James Hansen

James Hansen

James E. Hansen (born March 29, 1941 in Denison, Iowa) heads the NASA Goddard Institute for Space Studies in New York City, a part of the Goddard Space Flight Center in Greenbelt, Maryland, Earth Sciences Division. He has held this position since 1981. He is also an adjunct professor in the Department of Earth and Environmental Sciences at Columbia University.

After graduate school, Hansen continued his work with radiative transfer models and attempting to understand the Venusian atmosphere. This naturally led to the same computer codes in modified form being used to understand the Earth's atmosphere. He used these codes to study the effects that aerosols and trace gases have on the climate. Hansen has also contributed to the further understanding of the Earth's climate through the development and use of global climate models.

Hansen is best known for his research in the field of climatology, his testimony on climate change to congressional committees in the 1980s that helped raise broad awareness of global warming, and his advocacy of action to limit the impacts of climate change.

Hansen was trained in physics and astronomy in the space science program of Dr. James Van Allen at the University of Iowa. He obtained a B.A. in Physics and Mathematics with highest distinction in 1963, an M.S. in Astronomy in 1965 and a Ph.D. in Physics, in 1967, all three degrees from the University of Iowa. He participated in the NASA graduate traineeship from 1962 to 1966 and, at the same time, between 1965 and 1966, he was a visiting student at the Institute of Astrophysics at the University of Kyoto and in the Department of Astronomy at the University of Tokyo.

As a college student at the University of Iowa, Hansen was attracted to science and the research done by James Van Allen's space science program in the physics and astronomy department. A decade later, he focus shifted to planetary research that involved trying to understand the climate change on earth that will result from anthropogenic changes of the atmospheric composition.

Hansen has stated that one of his research interests in radiative transfer in planetary atmospheres, especially the interpretation of remote sensing of the Earth's atmosphere and surface from satellites. Because of the ability of satellites to monitor the entire globe, they may be one of the most effective ways to monitor and study global change. His other interests include the development of global circulation models to help understand the observed climate trends, and diagnosing human impacts on climate.

In the late 1960s and early 1970s, Hansen published several papers on the planet Venus following his Ph. D dissertation. Venus has a high brightness temperature in the radio frequencies compared to the infrared. Hansen proposed that the hot surface was the result of aerosols trapping the internal energy of the planet. More recent studies have suggested that several billion years ago Venus's atmosphere was much more like Earth's than it is now, and that there were probably substantial quantities of liquid water on the surface, but a runaway greenhouse effect was caused by the evaporation of that original water, which generated a critical level of es in its atmosphere.

Hansen continued his study of Venus by looking at the composition of its clouds. He looked at the near-infrared reflectivity of ice clouds, compared them to observations of Venus, and found that they qualitatively agreed. He also was able to use a radiative transfer model to establish an upper limit to the size of the ice particles if the clouds were actually made of ice. Evidence published in the early 1980s showed that the clouds consist mainly of sulfur dioxide and sulfuric acid droplets.

By 1974, the composition of Venus' clouds had not yet been determined, with many scientists proposing a wide variety of compounds including liquid water and aqueous solutions of ferrous chloride. Hansen and Hovenier used the polarization of sunlight reflected from the planet to establish that the clouds where spherical, and had a refractive index and effective radius which eliminated all of the proposed cloud types except sulfuric acid. Kawabata and Hansen expanded upon this work by looking at the variation of polarization on Venus. They found that the visible clouds are a diffuse haze rather than a thick cloud, which confirmed the same results obtained from transits across the sun.

The Pioneer Venus project was launched in May 1978 and reached Venus late that same year. Hansen collaborated with Travis and other colleagues in a 1979 Science article that reported on the development and variability of clouds in the ultraviolet spectrum. They conclude that there are at least three different cloud materials that contribute to the images: a thin haze layer, sulfuric acid clouds, and an unknown ultraviolet absorber below the sulfuric acid cloud layer. The linear polarization data obtained from the same mission confirmed that the low- and mid-level clouds were sulfuric acid with radius of about 1 micrometer. Above the cloud layer was a layer of submicrometre haze.

The first GISS global temperature data was published in 1987. They analyzed the surface air temperature at meteorological stations focusing on the years from 1880 to 1985. Temperatures for stations closer together than 1000 kilometers were shown to be highly correlated, especially in the mid-latitudes, which provided a way to combine the station data to provided accurate long-term variations. They conclude that global mean temperatures can be determined even though meteorological stations are typically in the Northern hemisphere and confined to continental regions. Warming in the past century was found to be 0.5-0.7 °C, with warming similar in both hemispheres. When the analysis was updated in 1988, the four warmest years on record were all in the 1980s. The two warmest years were 1981 and 1987.

With the eruption of Mount Pinatubo, 1992 saw a cooling in the global temperatures. There was speculation that this would cause the next few years to be cooler because of the large serial correlation in the global temperatures. Bassett and Lin found the statistical odds of a new temperature record to be small. Hansen countered by saying that having insider information shifts the odds to those that know the physics of the climate system, and that whether there is a new temperature record depends upon the particular data set used.

The temperature data was updated in 1999 to report that 1998 was the warmest year since the instrumental data began in 1880. They also found that the rate of temperature change was larger than any time in instrument history, and conclude that the recent El Nino was not totally responsible for the large temperature anomaly in 1998. In spite of this, the United States had seen a smaller degree of warming, and the eastern U.S. and the western Atlantic Ocean had actually cooled slightly.

2001 saw a major update to how the temperature was calculated. It incorporated corrections due to the following reasons: time-of-observation bias, station history changes, classification of rural/urban stations, the urban adjustment based on satellite measurements of night light intensity, and relying more on rural station than urban. Evidence was found of local urban warming in urban, suburban and small-town records.

The anomalously high global temperature in 1998 due to El Niño resulted in a brief drop in subsequent years. However, a 2001 Hansen report in the journal Science states that global warming continues, and that the increasing temperatures should stimulate discussions on how to slow global warming. The temperature data was updated in 2006 to report that temperatures are now 0.8 °C warmer than a century ago, and conclude that the recent global warming is a real climate change and not an artifact from the urban heat island effect. The regional variation of warming, with more warming in the higher latitudes, is further evidence of warming that is anthropogenic in origin.

In 2007, Stephen McIntyre notified GISS that many of the U.S. temperature records from the Historical Climatology Network (USHCN) displayed a discontinuity around the year 2000. NASA corrected the data and credited McIntyre with pointing out the flaw. Hansen indicated that he felt that several news organizations had overreacted to this mistake.

Hansen has also contributed toward the understanding of black carbon on regional climate. In recent decades, northern China has experienced increased drought, and southern China has received increased summer rain resulting in a larger number of floods. Southern China has had a decrease in temperatures while most of the world has warmed. In a paper with Menon and colleagues, though the use of observations and climate models results, they conclude that the black carbon heats the air, increases convection and precipitation, and leads to larger surface cooling than if the aerosols were sulfates.

A year later, Hansen teamed with Makiko Sato to publish a study on black carbon using the global network of AERONET sun photometers. While the location of the AERONET instruments did not represent a global sample, they could still be used to validate global aerosol climatologies. They found that most aerosol climatologies underestimated the amount of black carbon by a factor of at least 2. This corresponds to an increase in the climate forcing of around 1 W/m2, which they hypothesize is partially offset by the cooling of non-absorbing aerosols.

Estimations of trends in black carbon emissions show that there was a rapid increase in the 1880s after the start of the Industrial Revolution, and a leveling off from 1900-1950 as environmental laws were enacted. China and India have recently increased their emissions of black carbon corresponding to their rapid development. The emissions from the United Kingdom were estimated using a network of stations that measured black smoke and sulfur dioxide. They report that atmospheric black carbon concentrations have been decreasing since the beginning of the record in the 1960s, and that the decline was faster than the decline in black carbon producing fuel use. The current estimations of black carbon emissions are likely a factor of 2 lower than actual values.

A 2007 paper used the GISS climate model in an attempt to determine the origin of black carbon in the arctic. Much of the arctic aerosol comes from south Asia. Countries such as the United States and Russia have a lower contribution that previously assumed.

The United Nations Framework Convention on Climate Change is an international environmental treaty that was aimed at stabilizing greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.

In a 2004 presentation at the University of Iowa, Hansen announced that he was told by high-ranking government officials not to talk about how anthropogenic influence could have a dangerous effect on climate because it's not understood what dangerous means, or how human are actually affecting climate. The human-made influences of global warming are smaller than natural regional climate fluctuations. This is partially because the effects of aerosol, which act to cool the surface, and mask the warming effects of greenhouse gases. He describes this as a Faustian bargain because atmospheric aerosols have heath risks, and should be reduced, but doing so will effectively increase the warming effects from CO2.

Hansen et al. propose that the global mean temperature is a good tool to diagnose dangerous anthropogenic interference with the climate system. Two elements are particularly important when discussing dangerous anthropogenic interference: sea level rise and the extinction of species. They describe a business as usual scenario, which has greenhouse gases growing at approximately 2% per year, and an alternate scenario, in which greenhouse gases concentrations decline. Under the alternate scenario, sea levels could rise by 1 meter per century, causing problems due to the dense population in coastal areas. But this would be minor compared to the 10 meter increase in sea level under the business as normal scenario. Hansen describes the situation with species extinction similarly to sea level rise. Assuming the alternate scenario, the situation is not good, but it is much worse for business as usual.

The concept of dangerous anthropogenic interference was clarified in a 2007 paper. They find that further warming of 1C would be highly disruptive to humans. An alternative scenario would keep the warming to below this if climate sensitivity were below 3C for doubled CO2. The conclusion is that CO2 levels above 450 ppm are considered dangerous, but that reduction in non-CO2 greenhouse gases can provide temporary relief from drastic CO2 cuts. Further, they find that arctic climate change has been forced by non-CO2 constituents as much as CO2. They caution that prompt action is needed to slow CO2 growth and prevent a dangerous anthropogenic interference.

Vilhelm Bjerknes began the modern development of the general circulation model in the early twentieth century. The progress of numerical modeling was slow due to the slow speed of early computers and the lack of adequate observations. It wasn't until the 1950s that the numerical models were getting close to being realistic. Hansen's first contribution to numerical climate models came with the 1974 publication of the GISS model. He and his colleagues claimed that the model was successful in simulating the major features of sea-level pressure and 500mb heights in the North American region.

A 1981 Science publication by Hansen and a team of scientists at Goddard concluded that carbon dioxide in the atmosphere would lead to warming sooner than previously predicted. They used a one-dimensional radiative-convective model that calculates temperature as a function of height. They reported that the results from the 1D model are similar to the more complex 3D models, and can simulate basic mechanisms and feedbacks. Hansen predicted that temperatures would rise out of the climate noise by the 1990s, much earlier than predicted by other researches. He also predicted that it would be difficult to convince politicians and the public to react.

By the early 1980s the computational speed of computers, along with refinements in climate models, allowed longer experiments. The models now included physics beyond the previous equations, such as convection schemes, diurnal changes, and snow depth calculations. The advances in computational efficiency, combined with the added physics, meant the GISS model I could be run for five years. They showed that global climate can be simulated reasonably well with a grid-point resolution as coarse as 1000 kilometers.

The first climate prediction computed from a general circulation model that was published by Hansen was in 1988, the same year as his well-known Senate testimony. It used the second generation of the GISS model to estimate the change in mean surface temperature based on a variety of scenarios of future greenhouse gas emissions. Hansen concluded that global warming would be evident within the next few decades, and that it would result in temperatures at least as high as during the Eemian. He argued that, if the temperature rises 0.4 °C above the 1950-1980 mean for a few years, it is the "smoking gun" pointing to human-caused global warming.

In 2006, Hansen and colleagues compared the observations with the projections made by Hansen in his 1988 testimony before the United States Congress. They described the intermediate scenario as the most likely, and that real-world greenhouse gas forcing has been closest to this scenario. It contained the effects of three volcanic eruptions in the fifty year projections, with one in the 1995, whereas the recent Mount Pinatubo eruption was in 1991. They found that the observed warming was similar to two of the three scenarios. The warming rates of the two most modest warming scenarios are nearly the same through the year 2000, and they were unable to provide a precise model assessment. They did note that the agreement between the observations and the intermediate scenario was accidental because the climate sensitivity used was higher than current estimates.

A year later, he joined with Rahmstorf and colleagues comparing climate projections with observations. The comparison is done from 1990 through January 2007 against physics-based models that are independent from the observations after 1990. They show that the climate system may be responding faster than the models indicate. Rahmstorf et al. show concern that sea levels are rising at the high range of the IPCC projections, and that it is due to thermal expansion and not from the Greenland or Antarctic ice sheets.

Following the launch of spacecraft capable of determining temperatures, Roy Spencer and John Christy published the first version of their satellite temperature measurements in 1990. Contrary to climate models and surface measurements, their results showed a cooling in the troposphere. In 1998, Wentz and Schabel determined that orbital decay had an effect on the derived temperatures. Hansen compared the corrected troposphere temperatures with the results of the published GISS model, and concluded that the model is in good agreement with the observations, noting that the satellite temperature data had been the last holdout of global warming denialists, and that the correction of the data would result in a change from discussing whether global warming was occurring to what is the rate of global warming, and what should be done about it.

Hansen has continued the development and diagnostics of climate models. For instance, he has helped look at the decadal trends in tropopause height, which could be a useful tool for determining the human "fingerprint" on climate. As of 12 February 2009 (2009 -02-12), the current version of the GISS model is Model E. This version has seen improvements in many areas, including upper-level winds, cloud height, and precipitation. This model still has problems with regions of marine stratocumulus. A later paper showed that the model's main problems are having too weak of an ENSO-like variability, and poor sea ice modeling, resulting in too little ice in the Southern Hemisphere and too much in the Northern Hemisphere.

In 2000 he authored a paper called Global warming in the twenty-first century: an alternative scenario in which he presents a more optimistic way of dealing with global warming focusing on non-CO2 gases and black carbon in the short run, giving more time to make reductions in fossil fuel emissions. He notes that the net warming observed to date is roughly as big as that expected from non-CO2 gases only. This is because CO2 warming is offset by climate-cooling aerosols emitted with fossil fuel burning and because at that time non-CO2 gases, taken together, were responsible for roughly 50% of the anthropogenic greenhouse gas warming.

Hansen notes that in determining responsibility for climate change, the effect of greenhouse gas emissions on climate is not determined by current emissions, but by accumulated emissions over the lifetime of greenhouse gases in the atmosphere. By this measure the U.K. is still the largest single cause of climate change, followed by the U.S. and Germany, even though its current emissions are surpassed by the Peoples Republic of China.

Hansen has been particularly critical of the coal industry, stating that coal contributes the largest percentage of anthropogenic carbon dioxide into the atmosphere. He acknowledges that a molecule of carbon dioxide emitted from burning coal has the same effect as a molecule emitted from burning oil. The difference is where the fuel originally resides. He says that most oil comes from Russia and Saudi Arabia, and that no matter how fuel-efficient automobiles become, the CO2 will eventually be burned. In a 2007 testimony before the Iowa Utilities Board, he stated that the United States has a large reservoir of coal, which makes it a resource that can be controlled through action by U.S. politicians, unlike oil which is controlled by other countries. He has called for phasing out coal power completely by the year 2030.

During his testimony before the Iowa Utilities Board in 2007, Hansen likened coal trains to "death trains" and asserted that these would be "no less gruesome than if they were boxcars headed to crematoria, loaded with uncountable irreplaceable species." In response, the National Mining Association stated that his comparison "trivialized the suffering of millions" and "undermined his credibility." Citing the reactions of "several people" and "three of his scientific colleagues" as his primary motivation, Hansen stated that he certainly did not mean to trivialize suffering by the families who lost relatives in the Holocaust and then apologized saying he regretted that his words caused pain to some readers.

Hansen has stated that NASA administrators have tried to influence his public statements about the causes of climate change. Hansen claims that NASA public relations staff were ordered to review his public statements and interviews after a December 2005 lecture at the American Geophysical Union in San Francisco. NASA responded that its policies are similar to those of any other federal agency in requiring employees to coordinate all statements with the public affairs office without exception. Two years after Hansen and other agency employees described a pattern of distortion and suppression of climate science by political appointees, the agency’s inspector general found that the NASA Office of Public Affairs had mischaracterized the science of climate change intended for the public.

Hansen has also appeared on 60 Minutes stating that the White House edited climate-related press releases reported by federal agencies to make global warming seem less threatening. He claimed that he was unable to speak freely without the backlash of other government officials, and that he has not experienced that level of restrictions on communicating with the public during his career.

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Coal phase out

A coal phase-out is the decommissioning of operating coal-fired power plants and prevention of the construction of new coal-fired power stations. The purpose of this is to decrease the high concentration of carbon emissions, which may be causing climate change.

A significant portion of total global carbon emissions are from electricity generation - coal, specifically, accounts for up to one-third of global carbon emissions. So to decrease carbon emissions and thus possibly stop extreme climate change from occurring, coal should be phased out.

This course of action is being undertaken by several governments. Germany is an example of a country that is phasing out coal Solar and wind are now primary sources of energy and renewable energy generation is growing. Coal is still a source of power in Germany, but it is gradually being replaced with renewable energy. Globally, coal is one the largest sources of energy in the world - 40 percent of the world's energy is generated from the burning of coal. As a way to phase out coal, a few countries, in which coal is primary source of energy, have enacted legislation to prevent the construction of any new coal facilities and to close operating coal fired facilities. Also in several such countries, initiatives have been started to support the viability of the renewable energy industry to replace decommissioned coal facilities. However, many other countries, such as the United States and Great Britain, but especially China and India, are planning increased coal production to aid their economic advance. Both China and India have large reserves of coal, but relatively little oil, natural gas, hydro, solar or wind capacity, and are heavily dependent on coal for electricity generation.

Some believe that coal should not be phased out and that clean coal technology is the way all emission from the burning of coal can be restrained. But the renewable energy infrastructure, unlike unproven carbon-capture technology, is being deployed now. Some environmentalists and climatologists support a phase-out and criticise clean coal as not a solution to climate change, while entrepreneurs promote improved regulations and modernised technology. Others point out that such a policy would affect developing countries most seriously because of the scarcity of other fossil fuels.

The Australian Greens party have proposed to phase out coal power stations. The NSW Greens proposed an immediate moratorium on coal-fired power stations and want to end all coal mining and coal industry subsidies. The Federal Government's proposed Carbon Pollution Reduction Scheme, an emissions trading scheme will, once enacted, make it more difficult for new coal fired power stations to be developed. The Federal Government and Victorian State Government want to modify existing coal-fired power stations into clean coal power stations. The Federal Labor government extended the mandatory renewable energy targets, an initiative to ensure that new sources of electricity are more likely to be from wind power, solar power and other sources of renewable energy in Australia. However, the energy density of fossil fuels is such that green energy is unlikely to be able to meet electricity demands.

There are currently no plans to phase out coal burning power stations. On the contrary, more such stations are planned and being built to help China achieve its economic goals.

Current Chancellor Angela Merkel, and her party colleagues in 2007 agreed to legislation to phase out Germany's coal sector.

In October 2007 the Clark Labour government introduced a moratorium on coal-fired power plants. The ban was limited to state-owned utilities, though an extension to private sector was considered. The Key National government elected in November 2008 lifted the moratorium.

California's SB 1368 created the first governmental moratorium on new coal plants in the United States. The law was signed in September 2006, took effect for investor-owned utilities in January 2007, and took effect for publicly-owned utilities in August 2007. SB 1368 applied to long-term investments (five years or more) by California utilities, whether in-state or out-of-state. It set the standard for greenhouse gas emissions at 1,100 pounds of carbon dioxide per megawatt-hour, the equal to the emissions of a combined-cycle natural gas plant. This standard created a de facto moratorium on new coal, since it could not be met without carbon capture and sequestration.

On April 15, 2008, Maine Governor John E. Baldacci signed LD 2126, "An Act To Minimize Carbon Dioxide Emissions from New Coal-Powered Industrial and Electrical Generating Facilities in the State." The law, which was sponsored by Rep. W. Bruce MacDonald (D-Boothbay), requires the Board of Environmental Protection to develop greenhouse gas emission standards for coal gasification facilities. It also puts a moratorium in place on building any new coal gasification facilities until the standards are developed.

In January, 2007, A resolution calling for a 180-day moratorium on new pulverized coal plants was filed in the Texas Legislature on Wednesday by State Rep. Charles "Doc" Anderson (R-Waco) as House Concurrent Resolution 43. The resolution was left pending in committee. On December 4, 2007, Rep. Anderson announced his support for two proposed integrated gasification combined cycle (IGCC) coal plants proposed by Luminent (formerly TXU).

Washington has followed the same approach as California, prohibiting coal plants whose emissions would exceed those of natural gas plants. Substitute Senate Bill 6001 (SSB 6001), signed on May 3, 2007, by Governor Gregoire, enacted the standard. As a result of SSB 6001, the Pacific Mountain Energy Center in Kalama was rejected by the state. However, a new plant proposal, the Wallula Energy Resource Center, shows the limits of the "natural gas equivalency" approach as a means of stopping carbon dioxide emissions from coal plants. This proposed plant would meet the standard set by SSB 6001, even though it would capture and sequester a portion (65 percent, according to a plant spokesman) of its carbon.

In March, 2008, Henry A. Waxman and Edward J. Markey, co-chair of the U.S. House or Representatives Committee on Government Oversight and Reform, introduced H.R. 5575, the “Moratorium on Uncontrolled Power Plants Act of 2008.” The legislation addresses the largest new source of global warming pollution — new coal-fired power plants that are being built without any controls on their global warming emissions.

A 38-page document authored by James Hansen and eight other scientists, entitled “Target Atmospheric CO2: Where Should Humanity Aim?” calls for phasing out coal power completely by the year 2030 .

Kharecha and Hansen also consider three other mitigation scenarios, all with the same coal phase-out schedule but each making different assumptions about the size of oil and gas reserves and the speed at which they are depleted. Under the Business as Usual scenario, atmospheric CO2 peaks at 563 parts per million (ppm) in the year 2100. Under the four coal phase-out scenarios, atmospheric CO2 peaks at 422-446 ppm between 2045 and 2060 and declines thereafter. The key implications of the study are as follows: a phase-out of coal emissions is the most important remedy for mitigating human-induced global warming; actions should be taken toward limiting or stretching out the use of conventional oil and gas; and strict emissions-based constraints are needed for future use of unconventional fossil fuels such as methane hydrates and tar sands.

In the the Green Peace and EREC´s Energy (R)evolution scenario, the world could eliminate all fossil fuel use by 2090 .

In October, 2007, Civil Society Institute released the results of a poll of 1,003 U.S. citizens conducted by Opinion Research Corporation.

The authors of the poll reported: "75 percent of Americans –-including 65 percent of Republicans, 83 percent of Democrats and 76 percent of Independents --would 'support a five-year moratorium on new coal-fired power plants in the United States if there was stepped-up investment in clean, safe renewable energy --such as wind and solar --and improved home energy-efficiency standards.' Women (80 percent) were more likely than men (70 percent) to support this idea.Support also was higher among college graduates (78 percent) than among those who did not graduate from high school (68 percent).

The exact question posed by the survey was as follows: More than half of power plant-generated electricity comes from coal. Experts say that power plants are responsible for about 40 percent of U.S. carbon dioxide pollution linked to global warming. There are plans tobuild more than 150 new coal-fired power plants over the next several years. Would you support a five-year moratorium on new coal-fired power plants in the United States if there was stepped-up investment in clean, safe and renewable energy –such as wind and solar –and improved home energy-efficiency standards? Would you say definitely yes, probably yes, probably no, definitely no, or don't know.

In October, 2007, fifteen groups led by Citizens Lead for Energy Action Now (CLEAN) called for a five-year moratorium on new coal-fired power plants, with no exception for plants sequestering carbon. The groups included Save Our Cumberland Mountains (Tennessee); Ohio Valley Environmental Council (West Virginia); Cook Inlet Keeper (Alaska); Christians for the Mountains (West Virginia); Coal River Mountain Watch (West Virginia); Kentuckians for the Commonwealth (Kentucky); Civil Society Institute (Massachusetts); Clean Power Now (Massachusetts); Indigenous Environmental Network (Minnesota); Castle Mountain Coalition (Alaska); Citizens Action Coalition (Indiana); Appalachian Center for the Economy & the Environment (West Virginia); Appalachian Voices (NC); and Rhode Island Wind Alliance (Rhode Island).

In May, 2008, Laurie Williams and Allan Zabel, two lawyers at the Environmental Protection Agency, wrote a public letter opposing cap-and-trade solutions to greenhouse gas emissions and supporting a federal moratorium on new coal plants that don't sequester their carbon dioxide emissions. The letter, "Urgent Plea for Enactment of Carbon Fees and Ban on New Coal-Fired Power Plants without Carbon Sequestration," was written in their capacity as citizens rather than in their capacity as EPA employees.

Some electricity producers are changing from coal to renewables.

The Colorado Public Utilities Commission approved Xcel's voluntary decision to shut down two coal-fired power plants in the state and building one of the world's largest utility-scale solar power plants and adding 850 megawatts of wind energy to its system .

Biomass power is a growing trend in the United States . In 2006, Public Service of New Hampshire finished converting one of its coal-fired power plants into a 50-MW biomass power plant, the Northern Wood Power Project, which is fueled with wood chips. In 2008, DTE Biomass Energy (DTE Energy Company) agreed to buy the 50-MW E.J. Stoneman Power Plant in Cassville, Wisconsin, with plans to convert it to burn wood waste in 2009.

Georgia Power, a subsidiary of Southern Company, asked the state's public service commission for approval to convert the coal-fired Plant Mitchell to run on wood fuel. If approved, the retrofit will begin in 2011 and the biomass plant will start operating in mid-2012. The 96-MW biomass plant will run on surplus wood from suppliers within a 100-mile radius of the plant, which is located near Albany, Georgia.

Coal-fired power plant in Pepeekeo, Hawaii, that formerly provided electricity to a sugar mill is now being converted into a 24-megawatt (MW) biomass power plant. MMA Renewable Ventures is financing the conversion and will operate the new plant, which will be called the Hū Honua Bioenergy Facility . Located about 8 miles north of Hilo on the Big Island of Hawaii, the facility will draw on residual wood from the local timber industry and other biomass wastes to produce enough power for about 18,000 homes, meeting up to 10% of the Big Island's electricity needs.

Companies are also building new power plants designed to run on biomass.

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Greenpeace

Greenpeace is an international non-governmental organization for the protection and conservation of the environment. Greenpeace utilizes direct action, lobbying and research to achieve its goals. Greenpeace has a worldwide presence with national and regional offices in over 40 countries, which are affiliated to the Amsterdam-based Greenpeace International. The global organization receives its income through the individual contributions of an estimated 3 million financial supporters.

Greenpeace, originally known as the Greenpeace Foundation, was founded in Vancouver, British Columbia, Canada in 1972. On September 15, 1971, the Don't Make a Wave Committee sent an eighty foot halibut seiner “Phyllis Cormack”, from Vancouver, to oppose the United States testing nuclear devices in Amchitka, Alaska. While the boat never reached its destination and was turned back by the US military, this campaign was deemed the first using the name Greenpeace.

In 1972, the Greenpeace Foundation evolved in its own right to a less conservative and structured collective of environmentalists who were more reflective of the days counterculture and hippie youth movements who were spearheading the social revolution of the 1960s and 1970s. The social and cultural background from which Greenpeace emerged heralded a period of de-conditioning away from old world antecedents and sought to develop new codes of social, environmental and political behavior.

The focus of the organization later turned from anti-nuclear protest to other environmental issues: whaling, bottom trawling, global warming, old growth. nuclear power, and even genetically modified organisms.

Greenpeace is a global environmental organization that consists of Greenpeace International (Stichting Greenpeace Council) in Amsterdam and 28 national and regional offices around the world, providing a presence in 42 countries. These national and regional offices are largely autonomous in carrying out jointly agreed global campaign strategies within the local context they operate in and in seeking the necessary financial support from donors to fund this work. National and regional offices support a network of volunteer-run local groups. Local groups participate in many campaigns in their area and mobilize for larger protests and activities elsewhere. Millions of supporters who are not organized into local groups support Greenpeace by making financial donations and participating in campaigns as citizens and consumers.

Greenpeace runs campaigns and projects which fit into the "Issues" (as campaign areas are called within Greenpeace) categories below. Besides exposing problems such as over-fishing or threats linked to nuclear power, such as harmful radiation and proliferation, Greenpeace campaigns for alternative solutions such as marine reserves and renewable energy.

The organization currently addresses many and varied environmental issues with a primary focus on efforts to stop global warming and the preservation of the world's oceans and ancient forests. In addition to conventional environmental organization methods, such as lobbying businesses and politicians and participating in international conferences, Greenpeace uses [[nonviolencpaigns.

Greenpeace uses direct action to attract attention to particular environmental problems. For example, activists place themselves between the whaler's harpoons and their prey or invade nuclear facilities dressed as barrels of radioactive waste. Currently Greenpeace is in the midst of a campaign called Project Hot Seat, which is geared toward placing pressure on the United States Congress to stop global warming. Other initiatives include the development of a fuel-efficient car, the SmILE.

The EPIA/Greenpeace Advanced Scenario shows that by the year 2030, Photovoltaic systems could be generating approximately 2,600 TWh of electricity around the world. This means that, assuming a serious commitment is made to energy efficiency, enough solar power would be produced globally in twenty-five years’ time to satisfy the electricity needs of almost 14% of the world’s population.

In the the Green Peace and EREC´s Energy (R)evolution scenario, the world could eliminate fossil fuel use by 2090.

Think tanks, under the Greenpeace umbrella, propose blueprints for world's transition to renewable energy. The focus is to reduce carbon emissions without compromising on economic growth. The Solar Generation project, conceived in 2000 by Greenpeace and the European Photo- voltaic Industry Association (EPIA), addresses major energy challenges facing the global society and charts out the solar energy remedies until 2050. Greenpeace think tanks also focus on individual nation's energy scenarios. For example, Greenpeace has published scenarios where renewable resources like solar can become the backbone of the economies of developing countries like India, by 2050.

The origins of Greenpeace lie in the peace movement and the Campaign for Nuclear Disarmament generally, and particularly in the Don't Make A Wave Committee co-founded by Jim Bohlen, Patrick Moore, Paul Coté, and Irving Stowe, followed by an assortment of Canadian and expatriate American peace activists in Vancouver in 1970. Taking its name from a slogan used during protests against United States nuclear testing in late 1969, the Committee had come together with the objective of stopping a U.S. nuclear bomb test codenamed Cannikin beneath the Aleutian island of Amchitka, Alaska. The first ship expedition, inspired by the voyages of the Golden Rule, Phoenix and Everyman in 1958, was on the chartered West Coast fishing vessel, the "Phyllis Cormack," owned and sailed by John Cormack of Vancouver, and called the Greenpeace I; the second expedition was nicknamed Greenpeace Too!. The test was not prevented, but the voyage laid the groundwork for Greenpeace's later activities.

On 4 May 1972, following Dorothy Stowe's departure from the chairmanship of the Don't Make a Wave Committee, the fledgling environmental group officially changed its name to "The Greenpeace Foundation".

In 1972 the yacht Vega, a 12.5-metre (41 ft) ketch owned by David McTaggart (an eventual spokesman for Greenpeace International), was renamed Greenpeace III and sailed in an anti-nuclear protest into the exclusion zone at Mururoa in French Polynesia to attempt to disrupt French atmospheric nuclear testing. This voyage was sponsored and organised by the New Zealand branch of the Campaign for Nuclear Disarmament. CNDNZ and the New Zealand Peace Media had been lobbying the New Zealand Government and the New Zealand public to place pressure on Britain and France to agree to enforce a nuclear test ban in the South Pacific since the mid 1950s.

In 1973 the yacht Fri spearheaded an international protest of a flotilla of yachts in a voyage against atmospheric nuclear tests at Moruroa in French Polynesia. Fri was an important part of a series of anti-nuclear protest campaigns out of New Zealand and Australia which lasted thirty years, from which New Zealand declared itself a Nuclear free zone which became enshrined in legislation in what became the New Zealand Nuclear Free Zone, Disarmament, and Arms Control Act 1987. This voyage was organised by CNDNZ and the New Zealand Peace Media. In 1974, coordinated by Greenpeace New Zealand, the Fri embarked on a 3 year 40,233 kilometers “Pacific Peace Odyssey” voyage, carrying the peace message to all nuclear states around the world.

In 1974 the La Flor, from Melbourne, Australia, skippered by Rolf Heimann, a children's author, set out for Mururoa via New Zealand as Greenpeace IV but arrived after the final nuclear test for the year. The French military conducted more than 200 nuclear tests (40 of them atmospheric) at Mururoa and Fangataufa atolls over a thirty-year period ending in 1996.

In 1975 the Vancouver based Greenpeace Foundation mounted an anti-whaling campaign which encountered Soviet whalers over the seamounts off Mendocino, California. This campaign had been influenced by the work of Paul Spong and Farley Mowat as well as Robert Hunter's encounter with the Orca Skana.

In 1976 a campaign was launched against the killing and skinning of baby seals in Newfoundland for the high-fashion fur trade, targeting Norwegian ships engaged in the trade after receiving a hostile welcome from the Newfoundland fishermen involved in the hunt. Greenpeace used helicopters to move people and supplies to a base camp at Belle Isle. Brigitte Bardot later got involved in this campaign, to great effect. In the same year another anti-whaling expedition, using the James Bay as Greenpeace VII, disrupted the Soviet fleet again, but this time with the assistance of a "deep throat" source and extra funding from Ed Daly of World Airways. At about the same time visits to Japan were arranged to persuade the Japanese people that whaling should end.

By the late 1970s, spurred by the global reach of what Robert Hunter called "mind bombs", in which images of confrontation on the high seas converted diffuse and complex issues into considerably more media-friendly David versus Goliath-style narratives, more than 20 groups across North America, Europe, New Zealand and Australia had adopted the name "Greenpeace".

Greenpeace also engaged with its opponents through the courts both in Canada (defending a loitering charge for failing to leave a fisheries office) and in France (David McTaggart's Law of the Sea case to recover repair costs after his yacht Vega was damaged by the French navy).

Similarly, Greenpeace became involved with lobbying elected officials and various bodies such as the United Nations through events such as the Conference on the Human Environment and with the International Whaling Commission.

On August 21, 2007, Yvo de Boer, head of the UN Framework Convention on Climate Change (UNFCCC), angered environmental groups with his suggestion that "rich nations should be absolved from the need to cut emissions if they pay developing countries to do it on their behalf". Doug Parr of Greenpeace opposed Mr. de Boer's suggestion: "The current trading system is not delivering emissions reductions as it is ... Expanding it like this to give rich countries a completely free hand will simply not work." On August 22, 2007, the Philippine Department of Energy's plan to develop nuclear energy as an alternative source of power was opposed by Von Hernandez, campaign director of Greenpeace Southeast Asia, who warned that exploring nuclear options to bolster energy demand is "dangerous and misleading." He said the risks of accidents like Chernobyl or the most recent Kashiwazaki nuclear plant leak in Japan after an earthquake are real.

Four Greenpeace activists breached security at Heathrow Airport on February 25, 2008 to climb on top of a British Airways plane and protest plans to build a third runway On May 23, 2008, Greenpeace blocked coal shipments of Team Energy Philippines and intentions was to prevent expansion of coal power plants in the country. They sprayed a banner saying "Quit Coal" on the ship, but after negotiations they withdrew.

In September 2008, 6 Greenpeace activists who damaged a chimney at a power plant in the UK were declared "not guilty" of property destruction by a jury because they argued, through James Hansen who supported them in person, that they actually prevented greater property destruction due to climate change.

In 1979, the original Vancouver-based Greenpeace Foundation encountered financial difficulties. Disputes between offices over fund-raising and organizational direction split the global movement. David McTaggart lobbied the Canadian Greenpeace Foundation to accept a new structure which would bring the scattered Greenpeace offices under the auspices of a single global organization. On October 14, 1979, Greenpeace International came into existence. Under the new structure, the local offices would contribute a percentage of their income to the international organization, which would take responsibility for setting the overall direction of the movement.

Greenpeace's transformation from a loose international network to a global organization enabled it to apply the full force of its resources to a small number of environmental issues deemed of global significance, owing much to McTaggart's personal vision. McTaggart summed up his approach in a 1994 memo: "No campaign should be begun without clear goals; no campaign should be begun unless there is a possibility that it can be won; no campaign should be begun unless you intend to finish it off". McTaggart's own assessment of what could and could not be won, as well as how, frequently caused controversy.

In re-shaping Greenpeace as a centrally coordinated, hierarchical organization, McTaggart went against the anti-authoritarian ethos that prevailed in other environmental organizations that came of age in the 1970s. While this pragmatic structure granted Greenpeace the persistence and narrow focus necessary to match forces with government and industry, it would lead to the recurrent criticism that Greenpeace had adopted the same methods of governance as its chief foes, the multinational corporations. Its current Executive Director is Gerd Leipold.

For smaller actions and for continuous local promotion and activism, Greenpeace has networks of active supporters that coordinate their efforts through national offices. The United Kingdom has some 6,000 Greenpeace activists.

Since Greenpeace was founded, seagoing ships have played a vital role in its campaigns.

In 1978, Greenpeace launched the original Rainbow Warrior, a 40-metre (130 ft), former fishing trawler named for the Cree legend that inspired early activist Robert Hunter on the first voyage to Amchitka. Greenpeace purchased the Rainbow Warrior (originally launched as the Sir William Hardy in 1955) at a cost of £40,000. Volunteers restored and refitted it over a period of four months.

First deployed to disrupt the hunt of the Icelandic whaling fleet, the Rainbow Warrior would quickly become a mainstay of Greenpeace campaigns. Between 1978 and 1985, crew members also engaged in non-violent direct action against the ocean-dumping of toxic and radioactive waste, the Grey Seal hunt in Orkney and nuclear testing in the Pacific. Japan's Fisheries Agency has labeled Greenpeace ships as "anti-whaling vessels" and "environmental terrorists".

In 1985 the Rainbow Warrior entered into the waters surrounding Moruroa atoll, site of French nuclear testing. The sinking of the Rainbow Warrior occurred when the French government secretly bombed the ship in Auckland harbour on orders from François Mitterrand himself. This killed Dutch freelance photographer Fernando Pereira, who thought it was safe to enter the boat to get his photographic material after a first small explosion, but drowned as a result of a second, larger explosion. The attack was a public relations disaster for France after it was quickly exposed by the New Zealand police. The French Government in 1987 agreed to pay New Zealand compensation of NZ$13 million and formally apologised for the bombing. The French Government also paid ₣2.3 million compensation to the family of the photographer.

In 1989 Greenpeace commissioned a replacement vessel, also named the Rainbow Warrior, which remains in service today as the flagship of the Greenpeace fleet.

In 1996 the Greenpeace vessel MV Sirius was detained by Dutch police while protesting the import of genetically modified soybeans due to the violation of a temporary sailing prohibition, which was implemented because the Sirius prevented their unloading. The ship, but not the captain, was released half an hour later.

In 2005 the Rainbow Warrior II ran aground on and damaged the Tubbataha Reef in the Philippines while she was, ironically, on a mission to protect the very same reef. Greenpeace was fined $7,000 USD for damaging the reef and agreed to pay the fine, although it said that the Philippines government had given it outdated charts.

Greenpeace has been variously criticized for being too radical, too alarmist, or too mainstream, for using methods bordering on eco-terrorism, for having itself caused environmental damage in its activities, for taking positions which are not environmentally or economically sound, and for valuing non-human causes over human causes. These criticisms have been made by governments, industrial and political lobbyists and other environmental groups.

Greenpeace co-founder, Canadian Ecologist Patrick Moore left the organization in 1986 when it decided to support a universal ban on chlorine in drinking water, chlorine which Moore has called "the biggest advance in the history of public health" and "essential for our health." Moore has argued that Greenpeace today is motivated by politics rather than science and that none of his "fellow directors had any formal science education".

In March, 2007 a division dedicated to working more closely with the entertainment community, founded by Mark Warford and former Eurythmic Dave Stewart was established in Hollywood. Inaugural projects included the music release of 'Go Green', a celebrity-laden pop song that included Dave Stewart, Annie Lennox, Sarah McLachlan and newcomer Nadirah X and a cultural exchange with Greenpeace China and the Hollywood community. The affiliation with Greenpeace was closed in October, 2007 due gross misalignment. Founders Mark Warford and Dave Stewart continue under the banner of Weapons of Mass Entertainment.

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Global warming

Global warming is the increase in the average temperature of the Earth's near-surface air and the oceans since the mid-twentieth century and its projected continuation. Global surface temperature increased 0.74 ± 0.18 °C (1.33 ± 0.32 °F) during the 100 years ending in 2005. The Intergovernmental Panel on Climate Change (IPCC) concludes that anthropogenic greenhouse gases are responsible for most of the observed temperature increase since the middle of the twentieth century, and natural phenomena such as solar variation and volcanoes probably had a small warming effect from pre-industrial times to 1950 and a small cooling effect from 1950 onward. These basic conclusions have been endorsed by more than 40 scientific societies and academies of science, including all of the national academies of science of the major industrialized countries.

Climate model projections summarized in the latest IPCC report indicate that global surface temperature will likely rise a further 1.1 to 6.4 °C (2.0 to 11.5 °F) during the twenty-first century. The uncertainty in this estimate arises from the use of models with differing climate sensitivity, and the use of differing estimates of future greenhouse gas emissions. Some other uncertainties include how warming and related changes will vary from region to region around the globe. Although most studies focus on the period up to 2100, warming is expected to continue beyond 2100, even if emissions have stopped, because of the large heat capacity of the oceans and the lifespan of CO2 in the atmosphere.

Increasing global temperature will cause sea levels to rise< and will change the amount and pattern of precipitation, likely including an expanse of the subtropical desert regions. Other likely effects include Arctic shrinkage and resulting Arctic methane release, shrinkage of the Amazon rainforest (already very damaged by deforestation from logging and farming), increases in the intensity of extreme weather events, changes in agricultural yields, modifications of trade routes, glacier retreat, species extinctions and changes in the ranges of disease vectors. Directly linked to observed increases the intensity and frequency of natural disasters, global warming and climate change are now considered key drives behind rising global humanitarian and emergency relief needs.

Political and public debate continues regarding the appropriate response to global warming. The available options are mitigation to reduce further emissions; adaptation to reduce the damage caused by warming; and, more speculatively, geoengineering to reverse global warming. Most national governments have signed and ratified the Kyoto Protocol aimed at reducing greenhouse gas emissions.

The causes of the recent warming are an active field of research. The scientific consensus is that the increase in atmospheric greenhouse gases due to human activity has caused most of the warming observed since the start of the industrial era, and the observed warming cannot be satisfactorily explained by natural causes alone. This attribution is clearest for the most recent 50 years, which is the period when most of the increase in greenhouse gas concentrations took place and for which the most complete measurements exist.

The greenhouse effect was discovered by Joseph Fourier in 1824 and first investigated quantitatively by Svante Arrhenius in 1896. It is the process by which absorption and emission of infrared radiation by atmospheric gases warm a planet's lower atmosphere and surface. Existence of the greenhouse effect as such is not disputed even by those who do not agree that the recent temperature increase is attributable to human activity. The question is instead how the strength of the greenhouse effect changes when human activity increases the atmospheric concentrations of particular greenhouse gases.

Naturally occurring greenhouse gases have a mean warming effect of about 33 °C (59 °F), without which Earth would be uninhabitable. On Earth the major greenhouse gases are water vapor, which causes about 36–70 percent of the greenhouse effect (not including clouds); carbon dioxide (CO2), which causes 9–26 percent; methane (CH4), which causes 4–9 percent; and ozone, which causes 3–7 percent.

Human activity since the industrial revolution has increased the atmospheric concentration of various greenhouse gases, leading to increased radiative forcing from CO2, methane, tropospheric ozone, CFCs and nitrous oxide. The atmospheric concentrations of CO2 and methane have increased by 36% and 148% respectively since the mid-1700s. These levels are considerably higher than at any time during the last 650,000 years, the period for which reliable data has been extracted from ice cores. Less direct geological evidence indicates that CO2 values this high were last seen approximately 20 million years ago. Fossil fuel burning has produced approximately three-quarters of the increase in CO2 from human activity over the past 20 years. Most of the rest is due to land-use change, in particular deforestation.

CO2 concentrations are expected to continue to rise due to ongoing burning of fossil fuels and land-use change. The rate of rise will depend on uncertain economic, sociological, technological, and natural developments. The IPCC Special Report on Emissions Scenarios gives a wide range of future CO2 scenarios, ranging from 541 to 970 ppm by the year 2100. Fossil fuel reserves are sufficient to reach this level and continue emissions past 2100 if coal, tar sands or methane clathrates are extensively exploited.

The Earth's climate changes in response to external forcings, including those related to greenhouse gases, variations in its orbit around the Sun (orbital forcing), changes in solar luminosity, and volcanic eruptions. There are also positive and negative feedbacks which determine how the climate will respond to external forcing.

None of the effects of forcing are instantaneous. The thermal inertia of the Earth's oceans and slow responses of other indirect effects mean that the Earth's current climate is not in equilibrium with the forcing imposed. Climate commitment studies indicate that even if greenhouse gases were stabilized at 2000 levels, a further warming of about 0.5 °C (0.9 °F) would still occur.

One alternative hypothesis to the consensus view is that recent warming may be the result of variations in solar activity. A paper by Peter Stott and colleagues suggests that climate models overestimate the relative effect of greenhouse gases compared to solar forcing; they also suggest that the cooling effects of volcanic dust and sulfate aerosols have been underestimated. They nevertheless conclude that even with an enhanced climate sensitivity to solar forcing, most of the warming since the mid-20th century is likely attributable to the increases in greenhouse gases. Another paper suggests that the Sun may have contributed about 45–50 percent of the increase in the average global surface temperature over the period 1900–2000, and about 25–35 percent between 1980 and 2000.

Solar variation combined with changes in volcanic activity probably had a warming effect from pre-industrial times to 1950, but a cooling effect since. One predicted effect of an increase in solar activity would be a warming of most of the stratosphere, whereas an increase in greenhouse gases should produce cooling there. The observed trend since at least 1960 has been a cooling of the lower stratosphere. Reduction of stratospheric ozone also has a cooling influence, but substantial ozone depletion did not occur until the late 1970s. In 2006, Peter Foukal and colleagues found no net increase of solar brightness over the last 1,000 years. Solar cycles led to a small increase of 0.07 percent in brightness over the last 30 years. This effect is too small to contribute significantly to global warming.

A related hypothesis is that magnetic activity of the sun is a crucial factor which deflects cosmic rays that may influence the generation of cloud condensation nuclei and thereby affect the climate. Another paper found no relation between global warming and solar radiation since 1985, whether through variations in solar output or variations in cosmic rays. Henrik Svensmark and Eigil Friis-Christensen, the main proponents of cloud seeding by galactic cosmic rays, disputed this criticism of their hypothesis. A 2007 paper found that in the last 20 years there has been no significant link between changes in cosmic rays coming to Earth and cloudiness and temperature.

When a warming trend results in effects that induce further warming, the process is referred to as a positive feedback; when the effects induce cooling, the process is referred to as a negative feedback. The primary positive feedback involves water vapor. The primary negative feedback is the effect of temperature on emission of infrared radiation: as the temperature of a body increases, the emitted radiation increases with the fourth power of its absolute temperature. This provides a powerful negative feedback which stabilizes the climate system over time.

Global temperatures have increased by 0.75 °C (1.35 °F) relative to the period 1860–1900, according to the instrumental temperature record. This measured temperature increase is not significantly affected by the urban heat island effect. Since 1979, land temperatures have increased about twice as fast as ocean temperatures (0.25 °C per decade against 0.13 °C per decade). Temperatures in the lower troposphere have increased between 0.12 and 0.22 °C (0.22 and 0.4 °F) per decade since 1979, according to satellite temperature measurements. Temperature is believed to have been relatively stable over the one or two thousand years before 1850, with possibly regional fluctuations such as the Medieval Warm Period or the Little Ice Age.

Sea temperatures increase more slowly than those on land both because of the larger effective heat capacity of the oceans and because the ocean can lose heat by evaporation more readily than the land. The Northern Hemisphere has more land than the Southern Hemisphere, so it warms faster. The Northern Hemisphere also has extensive areas of seasonal snow and sea-ice cover subject to the ice-albedo feedback. More greenhouse gases are emitted in the Northern than Southern Hemisphere, but this does not contribute to the difference in warming because the major greenhouse gases persist long enough to mix between hemispheres.

Based on estimates by NASA's Goddard Institute for Space Studies, 2005 was the warmest year since reliable, widespread instrumental measurements became available in the late 1800s, exceeding the previous record set in 1998 by a few hundredths of a degree. Estimates prepared by the World Meteorological Organization and the Climatic Research Unit concluded that 2005 was the second warmest year, behind 1998. Temperatures in 1998 were unusually warm because the strongest El Niño-Southern Oscillation in the past century occurred during that year.

Anthropogenic emissions of other pollutants—notably sulfate aerosols—can exert a cooling effect by increasing the reflection of incoming sunlight. This partially accounts for the cooling seen in the temperature record in the middle of the twentieth century, though the cooling may also be due in part to natural variability. James Hansen and colleagues have proposed that the effects of the products of fossil fuel combustion—CO2 and aerosols—have, for the short term, largely offset one another, so that net warming in recent decades has been driven mainly by non-CO2 greenhouse gases.

Paleoclimatologist William Ruddiman has argued that human influence on the global climate began around 8,000 years ago with the start of forest clearing to provide land for agriculture and 5,000 years ago with the start of Asian rice irrigation. Ruddiman's interpretation of the historical record, with respect to the methane data, has been disputed.

Earth has experienced warming and cooling many times in the past. The recent Antarctic EPICA ice core spans 800,000 years, including eight glacial cycles timed by orbital variations with interglacial warm periods comparable to present temperatures.

A rapid buildup of greenhouse gases amplified warming in the early Jurassic period (about 180 million years ago), with average temperatures rising by 5 °C (9 °F). Research by the Open University indicates that the warming caused the rate of rock weathering to increase by 400%. As such weathering locks away carbon in calcite and dolomite, CO2 levels dropped back to normal over roughly the next 150,000 years.

Sudden releases of methane from clathrate compounds (the clathrate gun hypothesis) have been hypothesized as both a cause for and an effect of other warming events in the distant past, including the Permian–Triassic extinction event (about 251 million years ago) and the Paleocene–Eocene Thermal Maximum (about 55 million years ago).

Scientists have studied global warming with computer models of the climate. These models are based on physical principles including fluid dynamics and radiative transfer and are designed to be simplifications of the actual climate system. All modern climate models include an atmospheric model that is coupled to an ocean model and models for ice cover on land and sea. Some models also include treatments of chemical and biological processes. These models project a warmer climate due to increasing levels of greenhouse gases. Although a large amount of the variation in model outcomes depends on the greenhouse gas emissions used as inputs, the temperature effect of a specific greenhouse gas concentration (climate sensitivity) varies depending on the model used.

Global climate model projections of future climate depend on estimates of greenhouse gas emissions, most often those from the IPCC Special Report on Emissions Scenarios (SRES). In addition to human-caused emissions, some models also include a simulation of the carbon cycle; this generally shows a positive feedback, though this response is uncertain. Some observational studies also show a positive feedback. The representation of clouds is one of the main sources of uncertainty in present-generation models, though progress is being made on this problem.

Including uncertainties in future greenhouse gas concentrations and climate sensitivity, the IPCC anticipates a warming of 1.1 °C to 6.4 °C (2.0 °F to 11.5 °F) by the end of the 21st century, relative to 1980–1999. A 2008 paper predicts that the global temperature will not increase during the next decade because of short-term natural climate cycles.

Models are also used to help investigate the causes of recent climate change by comparing the observed changes to those that the models project from various natural and human-derived causes. Although these models do not unambiguously attribute the warming that occurred from approximately 1910 to 1945 to either natural variation or human effects, they do suggest that the warming since 1975 is dominated by man-made greenhouse gas emissions.

Current climate models produce a good match to observations of global temperature changes over the last century, but do not simulate all aspects of climate. Comparing model predictions with current climate is a good way to test the predictive power of models. While a 2007 study by David Douglass and colleagues found that the models did not accurately predict observed changes in the tropical troposphere, a 2008 paper published by a 17-member team led by Ben Santer noted errors in the Douglass study, and found instead that the models and observations were not statistically different. Not all effects of global warming are accurately predicted by the climate models used by the IPCC. For example, observed Arctic shrinkage has been faster than that predicted.

Although it is difficult to connect specific weather events to global warming, an increase in global temperatures may in turn cause broader changes, including glacial retreat, Arctic shrinkage, and worldwide sea level rise. Changes in the amount and pattern of precipitation may result in flooding and drought. There may also be changes in the frequency and intensity of extreme weather events. These changes are not likely to be reversible on timescales shorter than a thousand years. Other effects may include changes in agricultural yields, addition of new trade routes, reduced summer streamflows, species extinctions, and increases in the range of disease vectors.

Some effects on both the natural environment and human life are, at least in part, already being attributed to global warming. A 2001 report by the IPCC suggests that glacier retreat, ice shelf disruption such as that of the Larsen Ice Shelf, sea level rise, changes in rainfall patterns, and increased intensity and frequency of extreme weather events are attributable in part to global warming. Other expected effects include water scarcity in some regions and increased precipitation in others, changes in mountain snowpack, and adverse health effects from warmer temperatures.

Social and economic effects of global warming may be exacerbated by growing population densities in affected areas. Temperate regions are projected to experience some benefits, such as fewer deaths due to cold exposure. A summary of probable effects and recent understanding can be found in the report made for the IPCC Third Assessment Report by Working Group II. The newer IPCC Fourth Assessment Report summary reports that there is observational evidence for an increase in intense tropical cyclone activity in the North Atlantic Ocean since about 1970, in correlation with the increase in sea surface temperature (see Atlantic Multidecadal Oscillation), but that the detection of long-term trends is complicated by the quality of records prior to routine satellite observations. The summary also states that there is no clear trend in the annual worldwide number of tropical cyclones.

Additional anticipated effects include sea level rise of 0.18 to 0.59 meters (0.59 to 1.9 ft) in 2090-2100 relative to 1980-1999, repercussions to agriculture, possible slowing of the thermohaline circulation, reductions in the ozone layer, increasingly intense (but less frequent) hurricanes and extreme weather events, lowering of ocean pH, oxygen depletion in the oceans, and the spread of diseases such as malaria and dengue fever, as well as Lyme disease, hantavirus infections, bubonic plague, and cholera. One study predicts 18% to 35% of a sample of 1,103 animal and plant species would be extinct by 2050, based on future climate projections. However, few mechanistic studies have documented extinctions due to recent climate change and one study suggests that projected rates of extinction are uncertain.

Some economists have tried to estimate the aggregate net economic costs of damages from climate change across the globe. Such estimates have so far yielded no conclusive findings; in a survey of 100 estimates, the values ran from US$-10 per tonne of carbon (tC) (US$-3 per tonne of carbon dioxide) up to US$350/tC (US$95 per tonne of carbon dioxide), with a mean of US$43 per tonne of carbon (US$12 per tonne of carbon dioxide).

One widely publicized report on potential economic impact is the Stern Review. It suggests that extreme weather might reduce global gross domestic product by up to one percent, and that in a worst-case scenario global per capita consumption could fall 20 percent. The report's methodology, advocacy and conclusions have been criticized by many economists, primarily around the Review's assumptions of discounting and its choices of scenarios. Others have supported the general attempt to quantify economic risk, even if not the specific numbers.

Preliminary studies suggest that costs and benefits of mitigating global warming are broadly comparable in magnitude.

According to United Nations Environment Programme (UNEP), economic sectors likely to face difficulties related to climate change include banks, agriculture, transport and others. Developing countries dependent upon agriculture will be particularly harmed by global warming.

The broad agreement among climate scientists that global temperatures will continue to increase has led some nations, states, corporations and individuals to implement responses. These responses to global warming can be divided into mitigation of the causes and/or effects of global warming, and adaptation to the changing global environment.

By far the largest amount of political time and effort has gone into reducing in greenhouse gas emissions, principally through the Kyoto protocol. These efforts have been largely unsuccessful. Other approaches include carbon sequestration and certain geoengineering techniques.

The world's primary international agreement on combating global warming is the Kyoto Protocol, an amendment to the UNFCCC negotiated in 1997. The Protocol now covers more than 160 countries globally and over 55 percent of global greenhouse gas emissions. Only the United States and Kazakhstan have not ratified the treaty, with the United States historically being the world's largest emitter of greenhouse gases. This treaty expires in 2012, and international talks began in May 2007 on a future treaty to succeed the current one.

Many environmental groups encourage individual action against global warming, often by the consumer, but also by community and regional organizations. Others have suggested a quota on worldwide fossil fuel production, citing a direct link between fossil fuel production and CO2 emissions.

There has also been business action on climate change, including efforts at increased energy efficiency and limited moves towards use of alternative fuels. In January 2005 the European Union introduced its European Union Emission Trading Scheme, a greenhouse gas emissions trading scheme through which companies, in conjunction with government, agree to cap their emissions or to purchase credits from those below their allowances. Australia announced its Carbon Pollution Reduction Scheme in 2008. United States President Barack Obama has announced he will introduce an economy wide cap and trade scheme.

The IPCC's Working Group III is responsible for crafting reports that deal with the mitigation of global warming and analyzing the costs and benefits of different approaches. In the 2007 IPCC Fourth Assessment Report, they conclude that no one technology or sector can be completely responsible for mitigating future warming. They find there are key practices and technologies in various sectors, such as energy supply, transportation, industry, and agriculture, that should be implemented to reduced global emissions. They estimate that stabilization of carbon dioxide equivalent between 445 and 710 ppm by 2030 will result in between a 0.6 percent increase and three percent decrease in global gross domestic product.

Geoengineering would involve the deliberate modification of Earth's environment on a large scale "to suit human needs and promote habitability". It can be divided two major approaches. The first is remediation, in which greenhouse gases would be removed from the atmosphere, principally by carbon sequestration methods such as air capture. The second is solar radiation management, in which incoming solar radiation would be reduced, such as by the insertion of stratospheric sulfur aerosols. The slow pace of action to reduce greenhouse gas emissions have led some scientists to suggest that these techniques may be necessary. Whilst some cool roof and tree planting projects are underway, no planetary-scale geoengineering has yet been attempted.

Increased publicity of the scientific findings surrounding global warming has resulted in political and economic debate. Poor regions, particularly Africa, appear at greatest risk from the projected effects of global warming, while their emissions have been small compared to the developed world. At the same time, developing country exemptions from provisions of the Kyoto Protocol have been criticized by the United States and Australia, and used as part of a rationale for continued non-ratification by the U.S. In the Western world, the idea of human influence on climate has gained wider public acceptance in Europe than in the United States.

The issue of climate change has sparked debate weighing the benefits of limiting industrial emissions of greenhouse gases against the costs that such changes would entail. There has been discussion in several countries about the cost and benefits of adopting alternative energy sources in order to reduce carbon emissions. Business-centered organizations, conservative commentators, and companies such as the Competitive Enterprise Institute and ExxonMobil have downplayed IPCC climate change scenarios, funded scientists who disagree with the scientific consensus, and provided their own projections of the economic cost of stricter controls. Likewise, environmental organizations and a number of public figures have emphasized the potential risks of climate change and promote the implementation of GHG emissions reduction measures. Some fossil fuel companies have scaled back their efforts in recent years, or called for policies to reduce global warming.

Another point of contention is the degree to which emerging economies such as India and China should be expected to constrain their emissions. According to recent reports, China's gross national CO2 emissions may now exceed those of the U.S. China has contended that it has less of an obligation to reduce emissions since its per capita emissions are roughly one-fifth that of the United States. India, also exempt from Kyoto restrictions and another of the biggest sources of industrial emissions, has made similar assertions. The U.S. contends that if it must bear the cost of reducing emissions, then China should do the same.

A variety of issues are often raised in relation to global warming. One is ocean acidification. Increased atmospheric CO2 increases the amount of CO2 dissolved in the oceans. CO2 dissolved in the ocean reacts with water to form carbonic acid, resulting in acidification. Ocean surface pH is estimated to have decreased from 8.25 near the beginning of the industrial era to 8.14 by 2004, and is projected to decrease by a further 0.14 to 0.5 units by 2100 as the ocean absorbs more CO2. Since organisms and ecosystems are adapted to a narrow range of pH, this raises extinction concerns, directly driven by increased atmospheric CO2, that could disrupt food webs and impact human societies that depend on marine ecosystem services.

Global dimming, the gradual reduction in the amount of global direct irradiance at the Earth's surface, may have partially mitigated global warming in the late 20th century. From 1960 to 1990 human-caused aerosols likely precipitated this effect. Scientists have stated with 66–90% confidence that the effects of human-caused aerosols, along with volcanic activity, have offset some of the global warming, and that greenhouse gases would have resulted in more warming than observed if not for these dimming agents.

Ozone depletion, the steady decline in the total amount of ozone in Earth's stratosphere, is frequently cited in relation to global warming. Although there are areas of linkage, the relationship between the two is not strong.

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Climate Code Red: The Case for Emergency Action

Climate Code Red: The Case for Emergency Action is a 2008 book, published by Scribe Publications, which presents scientific evidence that the global warming crisis is worse than official reports and national governments have so far indicated. The book argues that we are facing a "sustainability emergency" that requires a clear break from business-as-usual politics. The authors explain that emergency action to address climate change is not so much a radical idea as an indispensable course we must embark upon. Climate Code Red draws heavily on the work of a large number of climate scientists, including James Hansen .

Co-author David Spratt is a Melbourne businessman, climate-policy analyst, and co-founder of the Carbon Equity network. Co-author Philip Sutton is convener of the Greenleap Strategic Institute and Assistant Convenor of the Climate Emergency Network.

The book was launched by the Governor of Victoria, Professor David de Kretser in Parliament House in Melbourne, Victoria, on July 17, 2008.

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The Environmentalist

The Environmentalist is a public interest, eco-investigative journalism site that reports on the geopolitics and science of climate change, general politics, sustainable living, business impact and the history of affected regions.

Founded in November, 2006, The Environmentalist's writers include Huffington Post environmental and geopolitical contributor, Janet Ritz; Presidential Climate Action Plan (PCAP) Executive Director, William S. Becker; award winning playwright and author, Sherman Yellen; author of the REAL McCAIN Cliff Schecter; filmmaker Greg Reitman, producer of the 2008 Sundance Film Festival award winning documentary, Fields of Fuel; Democratic Activist Terry Leach; as well as scientists, environmental lawyers and various guest contributors.

Founding Publisher and Managing Editor, Janet Ritz, is the daughter of award winning Associated Press courtroom artist and journalist, Rosalie Ritz. An environmental activist and writer who was mentored in her youth by writer and composer Joaquin Nin-Culmell, concert promoter Bill Graham and artist Zahara Schatz, Janet Ritz founded The Environmentalist in 2006 as a forum for unfiltered climate science information after learning from colleagues about the editing of James Hansen's climate science reports by the Bush administration.

In August, 2007, Ritz wrote an article for the Huffington Post: NASA's Climate Change Satellites: White House Cuts Leaked, which reported cuts in climate science satellites that were concurrent with a declaration by the Bush Administration to become more involved in fighting global warming . This led to an expansion of The Environmentalist's format to include topics beyond the environment. In January, 2008, The Environmentalist began to be picked up by wire services. In April, 2008, the editorial page was launched when Ritz published a tribute to her late mother's work on both The Huffington Post and The Environmentalist . World news, history and resource pages followed soon after.

The Environmentalist displays articles under the following sections (verticals): Home, Politics, Climate, World, Science, History, Business, Resources, Editorial, Lifestyle, Eco-Links, Tags and Archive. The articles are noted for their use of illustrations, photographs, charts and diagrams to clarify article points and conclusions.

A public interest site, The Environmentalist, is published under a Creative Commons 3.0 License with many of its articles carried by various online wire services, including Reuters, Chicago Sun-Times, Atlanta Journal-Constitution, Fox News, IBS and USA Today.

In November, 2008, The Environmentalist published an editorial by PCAP Executive Director, Bill Becker, entitled Struggling for Obama's Soul that followed a review of Becker's book, The 100 Day Action Plan to Save the Planet summarizing the Presidential Climate Action Plan developed for the incoming administration.

In August, 2008, The Environmentalist published filmmaker Greg Reitman's personal account, A Filmmaker's 'Fields of Fuel' of his journey that led to the 2008 Sundance Film Festival Audience Award winning documentary Fields of Fuel.

Hansen's letter was addressed to Prime Minister Yasuo Fukuda of Japan, host of the 2008 G8 Summit. He requested Fukuda's leadership in addressing the findings.

In May, 2008, an article by contributing writer, Terry Leach, entitled: Hillary Clinton's ‘Victory’ in Pennsylvania: The Rush Limbaugh Effect and subsequently picked up by Reuters , The Huffington Post , and The Chicago Sun-Times , posited that the votes for Hillary Clinton cast during the Pennsylvania Primary should be explored to assess the impact by Rush Limbaugh's Operation Chaos. This resulted in the phrase "The Limbaugh Effect" being used across the media sphere, which earned a response from Rush Limbaugh that was answered by The Environmentalist's managing editor in an article entitled: Why Rush Limbaugh Thinks This Site is Unfriendly .

More Published articles are listed on the Archives page.

In addition to their regular writers, The Environmentalist allows query submission by guest contributors. Interested writers submit a short synopsis through the site's contact page, along with their qualifications and reasons for writing.

On February 4, 2008, The Environmentalist endorsed Senator Barack Obama for President of the United States , citing his environmental policy positions as the reason for choosing him over the other candidates.

On January 31, 2008, Managing Editor, Janet Ritz, writing outside the environmentalism genre, reviewed and endorsed , a new release, Crossing the Line, by Ryko Recording Artist, Bill Cutler, an album that included deceased Grateful Dead lead guitarist, Jerry Garcia, among other surviving notables of the last three decades, many of whom had endorsed Senator Obama.

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