Usted no se lo cree

Fecha de nacimiento:

29/03/1941

Formación:

• 1963: B.A. in Physics and Mathematics with highest distinction (University of Iowa)
• 1967: M.S. in Astronomy in 1965 and a Ph.D.  in Physics (University of Iowa).
• 1962-1966: He participated in the NASA graduate traineeship
• 1965-1966: Visiting student at the Institute of Astrophysics at the University of Kyoto and in the Department of Astronomy at the University of Tokyo

Posición:

• Director del NASA Goddard Institute for Space Studies (New York)
• Catedrático del Department of Earth and Environmental Sciences, Columbia University

Áreas principales de conocimiento:

Temperatura, forzamientos: BC y otros gases, Dangerous Anthropogenic Interference, Venus

Observaciones:

Considerado el mejor climatólogo del mundo, desde 2008 dedica una parte de su actividad al activismo

Citas destacadas:

“Stabilizing climate is a moral issue, a matter of intergenerational justice. Young people, and older people who support the young and the other species on the planet, must unite in demanding an effective approach that preserves our planet.”

24/08/2010

“If humanity wishes to preserve a planet similar to that on which civilization developed and to which life on Earth is adapted, paleoclimate evidence and ongoing climate change suggest that CO2 will need to be reduced from its current 385 ppm to at most 350 ppm, but likely less than that.”

Target Atmospheric CO2: Where Should Humanity Aim? – The Open Atmospheric Science Journal 2:217-231 – February 2008

“The second fundamental property of Earth’s climate system, partnering with feedbacks, is the great inertia of oceans and ice sheets. Given the oceans’ capacity to absorb heat, when a climate forcing (such as increased greenhouse gases) impacts global temperature, even after two or three decades, only about half of the eventual surface warming has occurred. Ice sheets also change slowly, although accumulating evidence shows that they can disintegrate within centuries or perhaps even decades. The upshot of the combination of inertia and feedbacks is that additional climate change is already ‘in the pipeline’…”

Tipping Point. Perspective of a Climatologist – In: State of the Wild 2008-2009: A Global Portrait of Wildlife, Wildlands, and Oceans. W. Woods, Ed. Wildlife Conservation Society/Island Press, pp. 6-15.  – 28/04/2008

“The Venus syndrome is the greatest threat to the planet, to humanity’s continued existence… Now the danger that we face is the Venus syndrome. There is no escape from the Venus Syndrome. Venus will never have oceans again.”

Climate Threat to the Planet: The Venus Syndrome – Bjerknes Lecture, American Geophysical Union, San Francisco – 17/12/2008

Presencia en los medios convencionales:

James Hansen (1988) – The Greenhouse Effect: Impacts on Current Global Temperature and Regional Heat Waves – Guardian.co.uk – 23/06/1988  – http://image.guardian.co.uk/sys-files/Environment/documents/2008/06/23/ClimateChangeHearing1988.pdf
“I would like to draw three main conclusions. 1) The earth is warmer today than in any time in the history of instrumental measurements; 2) The global warming is large enough that we can ascribe with high degree of confidence … to the greenhouse effect; 3) Our computer simulations indicate that the greenhouse effect is already large enough to begin to effect the probability of extreme events such as summer heat waves.”

James Hansen (2007) – Climate Catastrophe: huge sea level rises are coming – unless we act now  – NewScientist 2614 – 25/07/2007 – http://www.newscientist.com/article/mg19526141.600-huge-sea-level-rises-are-coming–unless-we-act-now.html
“John Mercer effect: … I noticed that researchers who suggested that his paper was alarmist were regarded as more authoritative. It seems to me that scientists downplaying the dangers of climate change fare better when it comes to getting funding … After I published a paper in 1981 that described the likely effects of fossil fuel use, the US Department of Energy reversed a decision to fund my group’s research, specifically criticising aspects of that paper. I believe there is pressure on scientists to be conservative.”

James Hansen (2010) – Obama’s Second Chance on the Predominant Moral Issue of This Century – The Huffington Post – 05/04/2010 – http://www.huffingtonpost.com/dr-james-hansen/obamas-second-chance-on-c_b_525567.html
“Religions across the spectrum — Catholics, Jews, Mainline Protestants, Eastern Orthodox, and Evangelicals — are united in seeing climate change as a moral and ethical challenge. The Religious Coalition on Creation Care is working with the Citizen’s Climate Lobby, the Price Carbon Campaign, and economists at the Carbon Tax Center to help promote this honest and effective energy and climate policy. The public, if well-informed, can be expected to support this policy.”

Libros:

Storms of My Grandchildren (2009)

Declaraciones (testimonies)

James Hansen (1988) – The Greenhouse Effect: Impacts on Current Global Temperature and Regional Heat Waves – United States Senate – 23/06/1988
“Altogether the evidence that the earth is warming by an amount that is too large to be a chance fluctuation and the similarity of the warming to that expected from the greenhouse effect represents a very strong case. In my opinion, that the greenhouse effect has been detected, and it is changing our climate now.”

James Hansen (2008) – Global Warming Twenty Years Later: Tipping Points Near – Testimony to Congress – 3962223/06/2008 – http://www.columbia.edu/~jeh1/2008/TwentyYearsLater_20080623.pdf
“My presentation today is exactly 20 years after my 23 June 1988 testimony to Congress … Now we have used up all slack in the schedule for actions needed to defuse the global warming time bomb … Otherwise it will become impractical to constrain atmospheric carbon dioxide, the greenhouse gas produced in burning fossil fuels, to a level that prevents the climate system from passing tipping points that lead to disastrous climate changes that spiral dynamically out of humanity’s control.”

Papers destacados:

W.C. Wang, Y.L. Yung, A.A. Lacis, T. Mo and J.E. Hansen (1976) – Greenhouse Effects due to Man-Made Perturbations of Trace Gases – Science 194:685-690 doi:10.1126/science.194.4266.685 – 12/11/1976
“Nitrous oxide, methane, ammonia, and a number of other trace constituents in the earth’s atmosphere have infrared absorption bands in the spectral region 7 to 14 µm and contribute to the atmospheric greenhouse effect. The concentrations of these trace gases may undergo substantial changes because of man’s activities … These systematic effects on the earth’s radiation budget would have substantial climatic significance. It is therefore important that the abundances of these trace gases be accurately monitored to determine the actual trends of their concentrations.”

James Hansen et al (2005) – Earth’s Energy Imbalance: Confirmation and Implications – Science 308:1431-1435 doi: 10.1126/science.1110252 – 03/06/2005 – 15 autores
“Assume that initial stages of ice sheet disintegration are detected. Before action to counter this trend could be effective, it would be necessary to eliminate the positive planetary energy imbalance, now ~0.85 W/m2, which exists as a result of the ocean’s thermal inertia. Given energy infrastructure inertia and trends in energy use, that task could require on the order of a century to complete. If the time for a substantial ice response is as short as a century, the positive ice-climate feedbacks imply the possibility of a system out of our control.”

James Hansen et al (2005) – Efficacy of climate forcings – Journal of Geophysical Research 110: D18104 doi:10.1029/2005JD005776 – 38623 – NASA Goddard Institute for Space Studies and Columbia University Earth Institute – http://pubs.giss.nasa.gov/abstracts/2005/Hansen_etal_2.html – 45 authors
“One region that we find to be particularly susceptible to regional forcings is the Arctic (section 4.2). Climate response to anthropogenic ozone change and snow albedo change is concentrated in the Arctic and may be responsible for a substantial fraction of observed warming and sea ice loss. This suggests that reductions of these air pollutants, and their precursors, especially methane, may be an essential component of an effective strategy to slow anthropogenic climate change in the Arctic.”

James Hansen (2007) – Scientific reticence and sea level rise – Environmental Research Letters 2 024002 doi:10.1088/1748-9326/2/2/024002 – 24/05/2007
“I believe there is a pressure on scientists to be conservative. Papers are accepted for publication more readily if they do not push too far and are larded with caveats. Caveats are essential to science, being born in skepticism, which is essential to the process of investigation and verification. But there is a question of degree. A tendency for ‘gradualism’ as new evidence comes to light may be ill-suited for communication, when an issue with a short time fuse is concerned. However, these matters are subjective. I could not see how to prove the existence of a ‘scientific reticence’ about ice sheets and sea level. Score one for the plaintiff, and their ally and ‘friend of the court’, the United States federal government.”

James Hansen et al (2008) – Target Atmospheric CO2: Where Should Humanity Aim? – The Open Atmospheric Science Journal 2:217-231 doi:10.2174/1874282300802010217 – 10 authors – http://arxiv.org/abs/0804.1126
“The Intergovernmental Panel on Climate Change (ref) and others (ref) used several “reasons for concern” to estimate that global warming of more than 2-3°C may be dangerous. The European Union adopted 2°C above preindustrial global temperature as a goal to limit human-made warming (ref). Hansen et al. (ref) argued for a limit of 1°C global warming (relative to 2000, 1.7°C relative to preindustrial time), aiming to avoid practically irreversible ice sheet and species loss. This 1°C limit, with nominal climate sensitivity of ¾ °C per W/m2 and plausible control of other GHGs [6], implies maximum CO2 ~ 450 ppm (ref).”

James Hansen et al (2010) – Global Surface Temperature Change  – Reviews of Geophysics – http://data.giss.nasa.gov/gistemp/paper/gistemp2010_draft0803.pdf – 4 authors
«Figure 21 gives the lie to the frequent assertion that «global warming stopped in 1998». Of course it is possible to find almost any trend for a limited period via judicious choice of start and end dates of a data set that has high temporal resolution, but that is not a meaningful exercise. Even a more moderate assessment, «the trend in global surface temperature has been nearly flat since the late 1990s despite continuing increases in the forcing due to the sum of the well-mixed greenhouse gases» [Solomon et al., 2009], is not supported by our data. On the contrary, we conclude that there has been no reduction in the global warming trend of 0.15-0.20°C/decade that began in the late 1970s.»

Otros papers:

James Hansen (2009) – Survival of Tibetan Glaciers – Science briefs NASA – 29/12/2009 – http://www.giss.nasa.gov/research/briefs/hansen_14/
“Global warming must be the primary cause of glacier retreat, which is occurring on a global scale, but observed rapid melt rates suggest that other factors may be involved … Black soot, which includes black carbon (BC) and organic carbon (OC), absorbs sunlight and can speed glacial melting if BC reaches values of order 10 ng/g (nanograms per gram) or larger. The ice core data revealed that BC reached values of 20-50 ng/g in the 1950s and 1960s for the four stations that are downwind of European pollution sources. BC and OC amounts decreased strongly in the early 1970s, probably because of clean air regulations in Europe. However, the ice cores also reveal that in the past decade BC and OC began to increase again … The conclusion is that prospects for survival of Tibetan glaciers can be much improved by reducing black soot emissions. The black soot arises especially from diesel engines, coal use without effective scrubbers, and biomass burning, including cook stoves. Reduction of black soot via cleaner energies would have other benefits for human health and agricultural productivity. However, survival of the glaciers also requires halting global warming.”