|James Edward Hansen|
Hansen at the Our Opportunity student summit in March 2009
March 29, 1941 |
Denison, Iowa, U.S.
|Alma mater||University of Iowa|
|Known for||Radiative transfer, Planetary atmospheres,
|Influences||James Van Allen|
|Notable awards||United States National Academy of Sciences,
Carl-Gustaf Rossby Research Medal
James Edward Hansen (born March 29, 1941) is an American adjunct professor in the Department of Earth and Environmental Sciences at Columbia University. Hansen is best known for his research in the field of climatology, his testimony on climate change to congressional committees in 1988 that helped raise broad awareness of global warming, and his advocacy of action to avoid dangerous climate change. In recent years, Hansen has become an activist for action to mitigate the effects of climate change, which on a few occasions has led to his arrest.
After graduate school, Hansen continued his work with radiative transfer models, attempting to understand the Venusian atmosphere. Later he applied and refined these models to understand the Earth's atmosphere, in particular, the effects that aerosols and trace gases have on Earth's climate. Hansen's development and use of global climate models has contributed to the further understanding of the Earth's climate. In 2009 his first book, Storms of My Grandchildren, was published.
Early life and education 
Hansen was born in Denison, Iowa to James Ivan Hansen and Gladys Ray Hansen. He was trained in physics and astronomy in the space science program of 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. Hansen then began work at the Goddard Institute for Space Studies in 1967.
Research and publications 
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, his 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 is 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.
Studies of Venus 
In the late 1960s and early 1970s, following his Ph.D. dissertation, Hansen published several papers on the planet Venus. 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 greenhouse gases 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 were spherical, and had a refractive index and cloud drop effective radius which eliminated all of the proposed cloud types except sulfuric acid. Kiyoshi 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, confirming 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 Larry 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.
Global temperature analysis 
The first GISS (NASA Goddard Institute for Space Studies) global temperature analysis was published in 1981. Hansen and his co-author 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, providing 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 1991 eruption of Mount Pinatubo, 1992 saw a cooling in the global temperatures. There was speculation that this would cause the next couple 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 who 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 at any time in instrument history, and conclude that the recent El Niño 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 a region in 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 station; 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 computer code used to process the data and credited McIntyre with pointing out the flaw. Hansen indicated that he felt that several news organizations had overreacted to this mistake. In 2010, Hansen published a paper entitled "Global Surface Temperature Change" describing current global temperature analysis.
Black carbon studies 
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, through 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.
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 than previously assumed.
Anthropogenic impact on climate 
The United Nations Framework Convention on Climate Change is an international environmental treaty that has the objective of stabilizing greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.
In 2003, Hansen wrote a paper called "Can We Defuse the Global Warming Time Bomb?" in which he argued that human-caused forces on the climate are now greater than natural ones, and that this, over a long time period, can cause large climate changes. He further states that a lower limit on “dangerous anthropogenic interference” is set by the stability of the Greenland and Antarctic ice sheets. His view on actions to mitigate climate change is that "halting global warming requires urgent, unprecedented international cooperation, but the needed actions are feasible and have additional benefits for human health, agriculture and the environment."
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 humans are actually affecting climate. He describes this as a Faustian bargain because atmospheric aerosols have health risks, and should be reduced, but doing so will effectively increase the warming effects from CO2.
Hansen and coauthors 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-usual scenario. Hansen describes the situation with species extinction similarly to that of 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, finding that further warming of 1 °C would be highly disruptive to humans. An alternate scenario would keep the warming to below this if climate sensitivity were below 3 °C 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 findings are that arctic climate change has been forced by non-CO2 constituents as much as by CO2. The 2007 paper cautions that prompt action is needed to slow CO2 growth and to prevent a dangerous anthropogenic interference.
Climate model development and projections 
Vilhelm Bjerknes began the modern development of the general circulation model in the early 20th 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 those of 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. It was shown 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. The second generation of the GISS model was used 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, Hansen 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 and coauthors 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 melting of 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. However, 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 is 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[update], 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 clouds. 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.
Climate forcings, feedbacks, and sensitivity 
In 2000 Hansen authored a paper called "Global warming in the twenty-first century: an alternative scenario" in which he presented 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.
In a 2007 paper, Hansen discussed the potential danger of "fast-feedback" effects causing ice sheet disintegration, based on paleoclimate data. George Monbiot reports "The IPCC predicts that sea levels could rise by as much as 59 centimetres (1.94 ft) this century. Hansen’s paper argues that the slow melting of ice sheets the panel expects doesn’t fit the data. The geological record suggests that ice at the poles does not melt in a gradual and linear fashion, but flips suddenly from one state to another. When temperatures increased to 2–3°C (3.6–5.4°F) above today’s level 3.5 million years ago, sea levels rose not by 59 centimeters but by 25 metres (82 ft). The ice responded immediately to changes in temperature."
Hansen stressed the uncertainties around these predictions. "It is difficult to predict time of collapse in such a nonlinear problem ... An ice sheet response time of centuries seems probable, and we cannot rule out large changes on decadal time-scales once wide-scale surface melt is underway." He concludes that "present knowledge does not permit accurate specification of the dangerous level of human-made [greehouse gases]. However, it is much lower than has commonly been assumed. If we have not already passed the dangerous level, the energy infrastructure in place ensures that we will pass it within several decades."
Responsibility for climate change 
Hansen noted that in determining responsibility for climate change, the effect of greenhouse gas emissions on climate is determined not 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.
On public policy, Hansen is critical of what he sees as efforts to mislead the public on the issue of climate change. He points specifically to the Competitive Enterprise Institute's commercials with the tagline "carbon dioxide—they call it pollution, we call it life", and politicians who accept money from fossil-fuel interests and then describe global warming as "a great hoax." He also says that changes needed to reduce global warming do not require hardship or reduction in the quality of life, but will also produce benefits such as cleaner air and water, and growth of high-tech industries. He was a critic of both the Clinton and George W. Bush Administrations' stances on climate change. Addressing the potential effects of climate change, Hansen has stated in an interview in January, 2009, "We cannot now afford to put off change any longer. We have to get on a new path within this new administration. We have only four years left for Obama to set an example to the rest of the world. America must take the lead."
Climate change activism 
Criticism of coal industry 
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 oil will eventually be burned and the CO2 emitted. 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.
Mountaintop removal mining 
On June 23, 2009, James Hansen, along with 30 other protesters including actress Daryl Hannah, was arrested on misdemeanor charges of obstructing police and impeding traffic, during a protest against mountaintop removal mining in Raleigh County, West Virginia. The protesters intended to enter the property of Massey Energy Company, but were blocked by a crowd of several hundred coal miners and supporters. Hansen said that mountaintop removal for coal mining "[provides] only a small fraction of our energy" and "should be abolished." Hansen called on President Barack Obama to abolish mountaintop coal mining.
Cap and trade 
In 2009 Hansen spoke out against cap and trade, advocating instead what he believes would be a progressive carbon tax at source carbon as oil, gas or coal, with a 100% dividend returned to citizens in equal shares.
Retirement from NASA 
Hansen retired from NASA in April 2013, saying he planned to take a more active role in the political and legal efforts to limit greenhouse gases. The same month, the National Center for Science Education, an organization noted for opposing laws limiting the teaching of evolution in United States science classrooms, named Hansen as an advisor to support the organization's new efforts regarding the teaching of climate change.
Keystone Pipeline 
In a CBC interviewed aired in April 2013, as Joe Oliver (politician) lobbied in Washington, DC for approval of Keystone pipeline extension intended to carry more synthetic crude oil from Canada's Athabasca Oil Sands to the Gulf of Mexico,  Hansen forcefully argued against opening the spigot on to these very dirty unconventional fossil fuels. According to Intergovernmental panel on climate change IPCC and other energy organizations "there is more than twice as much carbon in the tar sands oil" than in conventional oil. Hansen argued that coal, tar sands, tar shale (dirtiest fossil fuels on the planet) should stay in the ground to stablilize the climate within a century and to protect future generations. Although in 2013 the amount of oil from the oil sands is small, if the XL extension is built, oil will be pumped from the oil sands for decades even to the end of the 21st century. He claims by opening the Keystone XL spigot, it would be game over for the climate. He argues that many governments are only worried about the next two or three years, denying and ignoring what will happen decades from now. In the case of emissions, "It's not the case where you emit something and you see the effect. We see the beginnings of the effect but the large impacts are going to be in future decades and that science is crystal clear ... Effects come slowly because of the inertia of the climate system. It takes decades, even centuries to get the full response. But we know the last time the world was 2 degrees warmer, sea level was 6 meters or 20 feet higher." Hansen urged President Obama to reject the Keystone pipeline extension intended to carry more synthetic crude oil from Canada's Athabasca Oil Sands to the Gulf of Mexico. On February 13, 2013, Hansen was again arrested at the White House, along with Daryl Hannah and Robert F. Kennedy, Jr., during a further protest against the proposed Keystone pipeline extension.
Proposed solutions 
At the end of 2008, Hansen stated five priorities that he felt then President-elect Obama should adopt "for solving the climate and energy problems, while stimulating the economy". The five priorities were: efficient energy use, renewable energy, a smart grid, generation IV nuclear reactors and carbon capture and storage. Regarding nuclear, he expressed opposition to the Yucca Mountain nuclear waste repository, stating that the $25 Billion (US) surplus held in the Nuclear Waste Fund "should be used to develop fast reactors that consume nuclear waste, and thorium reactors to prevent the creation of new long-lived nuclear waste."
In 2009 Hansen wrote an open letter to President Barack Obama where he advocated a "Moratorium and phase-out of coal plants that do not capture and store CO2". In his first book Storms of My Grandchildren, similarly, Hansen discusses his Declaration of Stewardship, the first principle of which requires "a moratorium on coal-fired power plants that do not capture and sequester carbon dioxide".
Honors and awards 
Hansen was elected to the National Academy of Sciences in 1996 for his "development of pioneering radiative transfer models and studies of planetary atmospheres; development of simplified and three-dimensional global climate models; explication of climate forcing mechanisms; analysis of current climate trends from observational data; and projections of anthropogenic impacts on the global climate system." In 2001, he received the 7th Annual Heinz Award in the Environment (endowed with US$250,000) for his research on global warming, and was listed as one of Time Magazine's 100 Most Influential People in 2006. Also in 2006, the American Association for the Advancement of Science (AAAS) selected James Hansen to receive its Award for Scientific Freedom and Responsibility "for his courageous and steadfast advocacy in support of scientists' responsibilities to communicate their scientific opinions and findings openly and honestly on matters of public importance."
In 2007, Hansen shared the US $1-million Dan David Prize for "achievements having an outstanding scientific, technological, cultural or social impact on our world". In 2008, he received the PNC Bank Common Wealth Award of Distinguished Service for his "outstanding achievements" in science. At the end of 2008, Hansen was named by EarthSky Communications and a panel of 600 scientist-advisors as the Scientist Communicator of the Year, citing him as an "outspoken authority on climate change" who had "best communicated with the public about vital science issues or concepts during 2008."
In 2009, Hansen was awarded the 2009 Carl-Gustaf Rossby Research Medal, the highest honor bestowed by the American Meteorological Society, for his "outstanding contributions to climate modeling, understanding climate change forcings and sensitivity, and for clear communication of climate science in the public arena."
Hansen won the 2010 Sophie Prize, set up in 1997 by Norwegian Jostein Gaarder, the author of the 1991 best-selling novel and teenagers' guide to philosophy Sophie's World, for his " key role for the development of our understanding of human-induced climate change."
Allegations of censorship 
In 2007, Hansen has stated that in 2005 NASA administrators had attempted to influence his public statements about the causes of climate change. Hansen said 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.
In June 2006, Hansen appeared on 60 Minutes stating that the George W. Bush White House had edited climate-related press releases reported by federal agencies to make global warming seem less threatening. He also stated that he was unable to speak freely without the backlash of other government officials, and that he had not experienced that level of restrictions on communicating with the public during his career.
Trials for energy company executives 
In 2008 interviews with ABC News, The Guardian, and in a separate op-ed, Hansen has called for putting fossil fuel company executives, including the CEOs of ExxonMobil and Peabody Coal, on trial for "high crimes against humanity and nature", on the grounds that these and other fossil-fuel companies had actively spread doubt and misinformation about global warming, in the same way that tobacco companies tried to hide the link between smoking and cancer.
Hansen and 1251 other activists were arrested in August and September 2011, at another demonstration in front of the White House. Hansen urged President Obama to reject the Keystone pipeline extension intended to carry more synthetic crude oil from Canada's Athabasca Oil Sands to the Gulf of Mexico. On February 13, 2013, Hansen was again arrested at the White House, along with Daryl Hannah and Robert F. Kennedy, Jr., during a further protest against the proposed Keystone pipeline extension.
In January 2009, Andrew Freedman wrote in the Washington Post, that the American Meteorological Society had erred in giving Hansen its Carl-Gustaf Rossby Research Medal: "His body of work is not at issue... Rather, the problem arises due to the AMS' recognition of Hansen's public communication work on climate change." Former AMS member Joseph D'Aleo, a skeptic of human-caused climate change, also criticized the award.
Also in 2009, physicist Freeman Dyson criticised Hansen's climate-change activism. "The person who is really responsible for this overestimate of global warming is Jim Hansen. He consistently exaggerates all the dangers... Hansen has turned his science into ideology." Hansen responded that if Dyson "is going to wander into something with major consequences for humanity and other life on the planet, then he should first do his homework". Dyson stated in an interview that the argument with Hansen was exaggerated by the New York Times, stating that he and Hansen are "friends, but we don't agree on everything."
After Hansen's arrest in 2009 in West Virginia, New York Times columnist Andrew Revkin wrote: "Dr. Hansen has pushed far beyond the boundaries of the conventional role of scientists, particularly government scientists, in the environmental policy debate." In 2009, Hansen advocated the participation of citizens at a March 2 protest at the Capitol Power Plant in Washington, D.C. Hansen stated, "We need to send a message to Congress and the president that we want them to take the actions that are needed to preserve climate for young people and future generations and all life on the planet".
In June 2009, New Yorker journalist Elizabeth Kolbert wrote that Hansen is "increasingly isolated among climate activists." Eileen Claussen, president of the Pew Center on Global Climate Change, said that "I view Jim Hansen as heroic as a scientist.... But I wish he would stick to what he really knows. Because I don't think he has a realistic idea of what is politically possible..."
In July 2009, New York Times climate columnist Christa Marshall asked if Hansen still matters in the ongoing climate debate, noting that he "has irked many longtime supporters with his scathing attacks against President Obama's plan for a cap-and-trade system." "The right wing loves what he's doing," said Joseph Romm, a senior fellow at the Center for American Progress, a think tank. Hansen said that he had to speak out, since few others could explain the links between politics and the climate models. "You just have to say what you think is right," he said.
See also 
- Kloor, Keith (November 26, 2009). "The eye of the storm". Nature Reports Climate Change. doi:10.1038/climate.2009.124. Retrieved December 19, 2009.
- Charles Sherwin Shene and Donna Hansen Stene, The Hansen Family, Decorah, IA, 2009, 56-57.
- David Herring (November 5, 2007). "Earth's Temperature Tracker". Earth Observatory. NASA. Retrieved March 19, 2010.
- "Dr. James E. Hansen". Personnel Directory. NASA. Retrieved February 2, 2009.
- Hansen, J.E., and S. Matsushima (1967). "The atmosphere and surface temperature of Venus: A dust insulation model". Astrophys. J. 150: 1139–1157. Bibcode:1967ApJ...150.1139H. doi:10.1086/149410.
- Kasting J.F. (1988). "Runaway and moist greenhouse atmospheres and the evolution of earth and Venus". Icarus 74 (3): 472–494. Bibcode:1988Icar...74..472K. doi:10.1016/0019-1035(88)90116-9. PMID 11538226.
- Hansen, J.E., and H. Cheyney (1968). "Near infrared reflectivity of Venus and ice clouds". J. Atmos. Sci. 25 (4): 629–633. Bibcode:1968JAtS...25..629H. doi:10.1175/1520-0469(1968)025<0629:NIROVA>2.0.CO;2.
- Hansen, J.E., and H. Cheyney (1968). "Comments on the paper by D.G. Rea and B.T. O'Leary, "On the composition of the Venus clouds"". J. Geophys. Res. 73 (18): 6136–6137. Bibcode:1968JGR....73.6136H. doi:10.1029/JB073i018p06136.
- Krasnopolsky V.A., Parshev V.A. (1981). "Chemical composition of the atmosphere of Venus". Nature 292 (5824): 610–613. Bibcode:1981Natur.292..610K. doi:10.1038/292610a0.
- Hansen, J.E., and J.W. Hovenier (1974). "Interpretation of the polarization of Venus". J. Atmos. Sci. 31 (4): 1137–1160. Bibcode:1974JAtS...31.1137H. doi:10.1175/1520-0469(1974)031<1137:IOTPOV>2.0.CO;2.
- Kawabata, K., and J.E. Hansen (1975). "Interpretation of the variation of polarization over the disk of Venus". J. Atmos. Sci. 32 (6): 1133–1139. Bibcode:1975JAtS...32.1133K. doi:10.1175/1520-0469(1975)032<1133:IOTVOP>2.0.CO;2.
- Travis, L.D., D.L. Coffeen, A.D. Del Genio, J.E. Hansen, K. Kawabata, A.A. Lacis, W.A. Lane, S.A. Limaye, W.B. Rossow, and P.H. Stone (1979). "Cloud images from the Pioneer Venus orbiter". Science 205 (4401): 74–76. Bibcode:1979Sci...205...74T. doi:10.1126/science.205.4401.74. PMID 17778907.
- Kawabata, K., D.L. Coffeen, J.E. Hansen, W.A. Lane, Mko. Sato, and L.D. Travis (1980). "Cloud and Haze Properties from Pioneer Venus Polarimetry". J. Geophys. Res. 85 (A13): 8129–8140. Bibcode:1980JGR....85.8129K. doi:10.1029/JA085iA13p08129.
- Hansen, J.E., and S. Lebedeff (1987). "Global trends of measured surface air temperature". J. Geophys. Res. 92 (D11): 13345–13372. Bibcode:1987JGR....9213345H. doi:10.1029/JD092iD11p13345.
- Hansen, J., and S. Lebedeff (1988). "Global surface air temperatures: Update through 1987". Geophys. Res. Lett. 15: 323–326. Bibcode:1988GeoRL..15..323H. doi:10.1029/GL015i004p00323.
- Bassett,G.W. Jr. and Z. Lin (1993). "Breaking global temperature records after Mt. Pinatubo". Climatic Change 25 (2): 179–184. doi:10.1007/BF01661205.
- Hansen, J., and H. Wilson (1993). "Commentary on the significance of global temperature records". Climatic Change 25 (2): 185–191. doi:10.1007/BF01661206.
- Hansen, J., R. Ruedy, J. Glascoe, and Mki. Sato (1999). "GISS analysis of surface temperature change". J. Geophys. Res. 104 (D24): 30997–31022. Bibcode:1999JGR...10430997H. doi:10.1029/1999JD900835.
- Hansen, J.E., R. Ruedy, Mki. Sato, M. Imhoff, W. Lawrence, D. Easterling, T. Peterson, and T. Karl (2001). "A closer look at United States and global surface temperature change". J. Geophys. Res. 106 (D20): 23947–23963. Bibcode:2001JGR...10623947H. doi:10.1029/2001JD000354.
- Hansen, J., R. Ruedy, Mki. Sato, and K. Lo (2002). "Global warming continues". Science 295 (5553): 275. doi:10.1126/science.295.5553.275c.
- Hansen, J., Mki. Sato, R. Ruedy, K. Lo, D.W. Lea, and M. Medina-Elizade (2006). "Global temperature change". Proc. Natl. Acad. Sci. 103 (39): 14288–14293. Bibcode:2006PNAS..10314288H. doi:10.1073/pnas.0606291103. PMC 1576294. PMID 17001018.
- "August 2007 update". GISS Surface Temperature Analysis. August 2007. Retrieved 6 February 2009.
- James Hansen (August 2007). "The Real Deal: Usufruct & the Gorilla". Retrieved 06 February 2009.
- Marc Kaufman (August 15, 2007). "NASA Revisions Create a Stir in The Blogosphere". The Washington Post. p. A6. Retrieved 2007-09-25.
- J. Hansen, R. Ruedy, M. Sato, and K. Lo (2010). "Global Surface Temperature Change". Reviews of Geophysics 48 (4). Bibcode:2010RvGeo..48.4004H. doi:10.1029/2010RG000345.
- Menon, S., J.E. Hansen, L. Nazarenko, and Y. Luo (2002). "Climate effects of black carbon aerosols in China and India". Science 297 (5590): 2250–2253. Bibcode:2002Sci...297.2250M. doi:10.1126/science.1075159. PMID 12351786.
- Novakov, T., and J.E. Hansen (2004). "Black carbon emissions in the United Kingdom during the past four decades: An empirical analysis". Atmos. Environ. 38 (25): 4155–4163. doi:10.1016/j.atmosenv.2004.04.031.
- Sato, Mki., J. Hansen, D. Koch, A. Lacis, R. Ruedy, O. Dubovik, B. Holben, M. Chin, and T. Novakov (2003). "Global atmospheric black carbon inferred from AERONET". Proc. Natl. Acad. Sci. 100 (11): 6319–6324. Bibcode:2003PNAS..100.6319S. doi:10.1073/pnas.0731897100. PMC 164444. PMID 12746494.
- Novakov, T., V. Ramanathan, J.E. Hansen, T.W. Kirchstetter, Mki. Sato, J.E. Sinton, and J.A. Satahye (2003). "Large historical changes of fossil-fuel black carbon aerosols". Geophys. Res. Lett. 30 (6): 1324. Bibcode:2003GeoRL..30f..57N. doi:10.1029/2002GL016345.
- Koch, D., and J. Hansen (2005). "Distant origins of Arctic black carbon: A Goddard Institute for Space Studies ModelE experiment". J. Geophys. Res. 110 (D4): D04204. Bibcode:2005JGRD..11004204K. doi:10.1029/2004JD005296.
- Jim Hansen (13 July 2006). "The Threat to the Planet". The New York Review of Books 53 (12).
- James Hansen (2003). "Can We Defuse the Global Warming Time Bomb?" (PDF).
- James Hansen (26 October 2004). "Dangerous Anthropogenic Interference". Retrieved 7 February 2009. "Natural regional climate fluctuations remain larger today than human-made effects such as global warming."
- Hansen, J., Mki. Sato, R. Ruedy, P. Kharecha, A. Lacis, R.L. Miller, L. Nazarenko, K. Lo, G.A. Schmidt, G. Russell, I. Aleinov, S. Bauer, E. Baum, B. Cairns, V. Canuto, M. Chandler, Y. Cheng, A. Cohen, A. Del Genio, G. Faluvegi, E. Fleming, A. Friend, T. Hall, C. Jackman, J. Jonas, M. Kelley, N.Y. Kiang, D. Koch, G. Labow, J. Lerner, S. Menon, T. Novakov, V. Oinas, Ja. Perlwitz, Ju. Perlwitz, D. Rind, A. Romanou, R. Schmunk, D. Shindell, P. Stone, S. Sun, D. Streets, N. Tausnev, D. Thresher, N. Unger, M. Yao, and S. Zhang (2007). "Dangerous human-made interference with climate: A GISS modelE study". Atmos. Chem. Phys. 7 (9): 2287–2312. doi:10.5194/acp-7-2287-2007.
- Spencer Weart (July 2008). "General Circulation Models of Climate". The Discovery of Global Warming. American Institute of Physics. Retrieved 11 February 2009.
- Somerville, R.C.J., P.H. Stone, M. Halem, J.E. Hansen, J.S. Hogan, L.M. Druyan, G. Russell, A.A. Lacis, W.J. Quirk, and J. Tenenbaum (1974). "The GISS model of the global atmosphere". Journal of the Atmospheric Sciences 31 (1): 84–117. Bibcode:1974JAtS...31...84S. doi:10.1175/1520-0469(1974)031<0084:TGMOTG>2.0.CO;2. ISSN 1520-0469. Unknown parameter
- Hansen, J., D. Johnson, A. Lacis, S. Lebedeff, P. Lee, D. Rind, and G. Russell (1981). "Climate impact of increasing atmospheric carbon dioxide". Science 213 (4511): 957–966. Bibcode:1981Sci...213..957H. doi:10.1126/science.213.4511.957. PMID 17789014.
- "Experts Find Possible Climatic 'Bomb'", Eleanor Randolph, Staff writer, Los Angeles Times, August 9, 1981, pg B3
- Hansen, J., G. Russell, D. Rind, P. Stone, A. Lacis, S. Lebedeff, R. Ruedy, and L. Travis (1983). "Efficient three-dimensional global models for climate studies: Models I and II". M. Weather Rev. Volume=111 111 (4): 609–662. Bibcode:1983MWRv..111..609H. doi:10.1175/1520-0493(1983)111<0609:ETDGMF>2.0.CO;2.
- Philip Shabecoff, Special to the New York Times (June 24, 1988). "Global Warming Has Begun, Expert Tells Senate". New York Times. Retrieved August 1, 2012. "...Dr. James E. Hansen of the National Aeronautics and Space Administration told a Congressional committee that it was 99 percent certain that the warming trend was not a natural variation but was caused by a buildup of carbon dioxide and other artificial gases in the atmosphere."
- Hansen, J., I. Fung, A. Lacis, D. Rind, Lebedeff, R. Ruedy, G. Russell, and P. Stone (1988). "Global climate changes as forecast by Goddard Institute for Space Studies three-dimensional model". J. Geophys. Res. 93: 9341–9364. doi:10.1029/88JD00231.
- Rahmstorf, S., A. Cazenave, J.A. Church, J.E. Hansen, R.F. Keeling, D.E. Parker, and R.C.J. Somerville (2007). "Recent climate observations compared to projections". Science 316 (709): 709. Bibcode:2007Sci...316..709R. doi:10.1126/science.1136843. PMID 17272686. "Previous projections, as summarized by IPCC, have not exaggerated but may in some respects even have underestimated the change."
- Spencer, R.W. And J.R. Christy (1990). "Precise Monitoring of Global Temperature Trends from Satellites". Science 247 (4950): 1558–1562. Bibcode:1990Sci...247.1558S. doi:10.1126/science.247.4950.1558. PMID 17782811.
- Wentz, F.J. and M. Schabel (1998). "Effects of orbital decay on satellite-derived lower-tropospheric temperature trends". Nature 394 (6694): 661–664. Bibcode:1998Natur.394..661W. doi:10.1038/29267.
- Hansen, J.E., Mki. Sato, R. Ruedy, A. Lacis, and J. Glascoe (1998). "Global climate data and models: A reconciliation". Science 281 (5379): 930–932. doi:10.1126/science.281.5379.930.
- Santer, B.D., R. Sausen, T.M.L. Wigley, J.S. Boyle, K. AchutaRao, C. Doutriaux, J.E. Hansen, G.A. Meehl, E. Roeckner, R. Ruedy, G. Schmidt, and K.E. Taylor (2003). "Behavior of tropopause height and atmospheric temperature in models, reanalyses, and observations: Decadal changes". J. Geophys. Res. 108 (D1): 4002. Bibcode:2003JGRD..108.4002S. doi:10.1029/2002JD002258.
- Schmidt, G.A., R. Ruedy, J.E. Hansen, I. Aleinov, N. Bell, M. Bauer, S. Bauer, B. Cairns, V. Canuto, Y. Cheng, A. Del Genio, G. Faluvegi, A.D. Friend, T.M. Hall, Y. Hu, M. Kelley, N.Y. Kiang, D. Koch, A.A. Lacis, J. Lerner, K.K. Lo, R.L. Miller, L. Nazarenko, V. Oinas, Ja. Perlwitz, Ju. Perlwitz, D. Rind, A. Romanou, G.L. Russell, Mki. Sato, D.T. Shindell, P.H. Stone, S. Sun, N. Tausnev, D. Thresher, and M.-S. Yao (2006). "Present day atmospheric simulations using GISS ModelE: Comparison to in-situ, satellite and reanalysis data". J. Climate 19 (2): 153–192. Bibcode:2006JCli...19..153S. doi:10.1175/JCLI3612.1.
- Hansen, J., Mki. Sato, R. Ruedy, P. Kharecha, A. Lacis, R.L. Miller, L. Nazarenko, K. Lo, G.A. Schmidt, G. Russell, I. Aleinov, S. Bauer, E. Baum, B. Cairns, V. Canuto, M. Chandler, Y. Cheng, A. Cohen, A. Del Genio, G. Faluvegi, E. Fleming, A. Friend, T. Hall, C. Jackman, J. Jonas, M. Kelley, N.Y. Kiang, D. Koch, G. Labow, J. Lerner, S. Menon, T. Novakov, V. Oinas, Ja. Perlwitz, Ju. Perlwitz, D. Rind, A. Romanou, R. Schmunk, D. Shindell, P. Stone, S. Sun, D. Streets, N. Tausnev, D. Thresher, N. Unger, M. Yao, and S. Zhang (2007). "Climate simulations for 1880-2003 with GISS modelE". Clim. Dynam. 29 (7-8): 661–696. arXiv:physics/0610109. Bibcode:2007ClDy...29..661H. doi:10.1007/s00382-007-0255-8.
- Hansen, James; et al. (2000). "Global warming in the twenty-first century: An alternative scenario". Proc. Natl. Acad. Sci. 97 (18): 9875–9880. Bibcode:2000PNAS...97.9875H. doi:10.1073/pnas.170278997. PMC 27611. PMID 10944197.
- Hansen, James; et al. (2007). "Climate change and trace gases" (PDF). Phil. Trans. Roy. Soc. A 365 (1856): 1925–1954. Bibcode:2007RSPTA.365.1925H. doi:10.1098/rsta.2007.2052. PMID 17513270.
- Intergovernmental Panel on Climate Change (February 2007). "Climate Change 2007: The Physical Science Basis - Summary for Policymakers. Table SPM-3." (PDF).
- George Monbiot (3 July 2007). "A Sudden Change of State.".
- Adam, David (18 March 2009). "Leading climate scientist: 'democratic process isn't working'". The Guardian. Retrieved 2009-03-19.
- "Hansen's Kingsnorth testimony" (PDF). Retrieved 2 February 2009.
- Sutherland, J.J. (May 23, 2006). "They Call It Pollution. We Call It Life". NPR. Retrieved February 2, 2009.
- Hansen, James (November 21, 2006). "The Threat to the Planet: How Can We Avoid Dangerous Human-Made Climate Change?". Remarks of James E. Hansen on 21 November 2006 On Acceptance of WWF Duke of Edinburgh Conservation Medal. Columbia University. Retrieved February 5, 2009.
- Hansen, James (February 10, 2006). "Can We Still Avoid Dangerous Human-Made Climate Change?". Retrieved February 10, 2009.
- Schorn, Daniel (July 30, 2006). "Rewriting The Science". CBS News. Retrieved February 5, 2009.
- McKie, Robin (January 18, 2009). "'We have only four years left to act on climate change - America has to lead'". The Guardian. Retrieved February 2, 2009.
- "Direct Testimony of James E. Hansen". State of Iowa: Before the Iowa Utilities Board. Retrieved February 2, 2009.
- Hansen, J., Mki. Sato, P. Kharecha, D. Beerling, R. Berner, V. Masson-Delmotte, M. Pagani, M. Raymo, D.L. Royer, and J.C. Zachos (2008). "Target Atmospheric CO2: Where Should Humanity Aim?". Open Atmos. Sci. J. 2 (1): 217–231. arXiv:0804.1126. Bibcode:2008OASJ....2..217H. doi:10.2174/1874282300802010217. Retrieved February 2, 2009.
- Revkin, Andrew (November 26, 2007). "Climate, Coal and Crematoria". The New York Times. Retrieved February 2, 2009.
- "Hansen's correspondence with NMA re "coal crematoria"". Retrieved February 2, 2009.
- More from NASA's Hansen on coal Des Moines Register / Knight Science Journalism at MIT, November 7, 2007, Retrieved November 23, 2012
- Hansen, James (November 28, 2007). "Averting Our Eyes". James Hansen. Retrieved February 6, 2009.
- "Hannah, Hansen arrested in mountaintop removal protest". West Virginia Public Broadcasting. June 23, 2009.
- "Daryl Hannah, scientist among 30 arrested at W.Va. mine protest". Charleston Gazette. June 23, 2009.
- Revkin, Andrew C. (June 23, 2009). "Hansen of NASA Arrested in Coal Country". New York Times. Retrieved May 5, 2010.
- "A Plea To President Obama: End Mountaintop Coal Mining". Environment 360. Yale University. 22 June 2009.
- Associated Press. "About 100 arrested in DC mountaintop mining rally". Los Angeles Times.
- "Police Arrest Dozens Of People Protesting Mountaintop Mining". Nasdaq (Dow Jones). September 27, 2010. Retrieved September 27, 2010.
- James Hansen. Letter to Obama http://www.columbia.edu/~jeh1/mailings/20081229_DearMichelleAndBarack.pdf accessed December 10 2009.
- Bone, James (December 3, 2009). "Climate scientist James Hansen hopes summit will fail". Timesonline. Retrieved December 10, 2009.
- Randerson, James (January 2, 2009). "Nasa climate expert makes personal appeal to Obama". The Guardian. Retrieved December 10, 2009.
- James Hansen. Tell Barack Obama the Truth – The Whole Truth. http://www.columbia.edu/~jeh1/mailings/20081229_Obama_revised.pdf accessed 10 December 2009.
- Kloor, Keith (November 26, 2009). "The Eye of the Storm". Nature Reports Climate Change. Retrieved December 11, 2009.
- "Climate Maverick to Quit NASA". New York Times. Retrieved 1 April 2013.
- National Center for Science Education (5 April 2013). "Three new climate advisors for NCSE". Retrieved 9 April 2013.
- "Climate test for Obama: 1,252 people arrested over notorious oil pipeline". Mongabay. September 6, 2011.
- Fitzpatrick, Meagan (27 April 2013). "Top U.S. climate expert calls Conservatives 'Neanderthal' Former NASA scientist James Hansen fires back at Natural Resources Minister Joe Oliver". CBC News.
- "Climate test for Obama: 1,252 people arrested over notorious oil pipeline". Mongabay. September 6, 2011.
- Suzanne Goldenberg (February 13, 2013). "Daryl Hannah leads celebrity Keystone XL protest at White House gates". The Guardian. Retrieved April 13, 2013.
- Hansen, James (2009). Storms of My Grandchildren. London: Bloomsbury Publishing. p. 242. ISBN 1-4088-0745-9.
- "Directory of the National Academy of Sciences". Retrieved 2007-06-19.
- "The Heinz Awards, James Hansen profile". Retrieved 2008-09-27.
- "AAAS Award for Scientific Freedom and Responsibility: James Hansen". American Association for the Advancement of Science. Retrieved 5 February 2009.
- "NASA Climate Scientist Honored by American Meteorological Society". NASA. 14 January 2009. Retrieved 5 February 2009.
- "AMS Awards". American Meteorological Society. Retrieved 05 February 2009.
- "Climate scientist Hansen wins $100,000 prize". Reuters. 7 April 2010. Retrieved 7 April 2010.
- "The FP Top 100 Global Thinkers". Foreign Policy. 26 November 2012. Archived from the original on 28 November 2012. Retrieved 28 November 2012.
- Baker, David R (December 5, 2012). "Climate guru slams cap and trade". San Francisco Chronicle (Hearst Newspapers). Retrieved January 1, 2013.
- Juliet Eilperin (January 18, 2005). "Putting Some Heat on Bush". Washington Post. Retrieved June 20, 2007.
- Andrew Revkin (January 29, 2006). "Climate Expert Says NASA Tried to Silence Him". The New York Times. Retrieved June 20, 2007. "They feel their job is to be this censor of information going out to the public."
- Bill Blakemore (January 29, 2006). "Top NASA Scientist Says He's Being Silenced on Global Warming". ABC News. Retrieved June 20, 2008.
- Andrew C. Revkin (June 3, 2008). "NASA Office Is Criticized on Climate Reports". The New York Times.
- Daniel Schorn (June 30, 2006). "Rewriting the Science". CBS. Retrieved February 7, 2009.
- Clayton Sandell (June 23, 2008). "Global Warming 20 Years Later". ABC News. Retrieved 2008-06-23.
- Ed Pilkington (23 June 2008). "Put oil firm chiefs on trial, says leading climate change scientist". London: The Guardian. Retrieved 6 February 2009.
- James Hansen (2008-06-23). "Guest Opinion: Global Warming Twenty Years Later". Worldwatch Institute. Retrieved 2008-06-23. "In my opinion, these CEOs should be tried for high crimes against humanity and nature."
- "Climate test for Obama: 1,252 people arrested over notorious oil pipeline". Mongabay. September 6, 2011.
- Freedman, Andrew (January 29, 2009). "Science Group Erred Giving Hansen Top Honor". Washington Post.
- Revkin, Andrew (January 14, 2009). "Weather Mavens Honor Climate Maven". New York Times.
- Dawidoff,, Nicholas (March 25, 2009). "The Civil Heretic". New York Times.
- A conversation with theoretical physicist and mathematician Freeman Dyson. Charlie Rose. August 14, 2009. http://www.charlierose.com/view/interview/10560. Retrieved November 21, 2010.
- Joshua Rhett Miller (February 27, 2009). "NASA's Chief Climate Scientist Stirs Controversy With Call for Civil Disobedience". Fox News. Retrieved August 27, 2010.
- Kolbert, Elizabeth (June 29, 2009). Abstract "The Catastrophist". The New Yorker.
- Marshall, Christa (July 14, 2009). "Does NASA's James Hansen Still Matter in Climate Debate?". New York Times.
Further reading 
- Bowen, Mark (2008). Censoring Science: Inside the Political Attack on Dr. James Hansen and the Truth of Global Warming. New York: Dutton. ISBN 978-0-525-95014-1.
- James Hansen's page at Columbia University
- James Hansen's page at the Goddard Institute for Space Studies
- Media related to James Hansen at Wikimedia Commons