Listen up Hillary.
New research co-authored by leading U.S. climate scientist James Hansen, a longtime employee of NASA who recently resigned to engage in climate activism, paints a grim picture of a future Earth left virtually uninhabitable by current warming trends. The paper, published Monday, concludes that energy-related decisions being made by today's government leaders will ultimately "determine the fate of humanity."
Hansen's paper, authored with several former NASA colleagues, warns that Earth's climate-regulating systems may be more sensitive to higher levels of carbon than scientists previously suspected. They also calculated the atmospheric changes that would be produced by burning off the estimated stock of Earth's fossil fuel reserves, finding that it would result in a planetary apocalypse.
"Burning all fossil fuels, we conclude, would make most of the planet uninhabitable by humans, thus calling into question strategies that emphasize adaptation to climate change," they write. Such a scenario, with average temperatures rising 16 degrees Celsius on land and 30 degrees Celsius at the poles, would leave just a fraction of humanity clinging to life atop Earth's highest ridges, Hansen et. al. predict.
Climate denialists have in recent months seized upon a strategy of downplaying the likelihood of climate-driven mass extinctions within the next 50-100 years, urging government officials to instead adopt policies that aim to help humanity adapt to climate change -- which they claim will be less than 2 degrees Celsius, bringing about unforeseen benefits.
By comparison, the World Bank warned last year that a rise of just 4 degrees Celsius is looking almost inevitable on our current track. Such a change would cause widespread famine, droughts, intensifying storm systems and mass population movements across dozens of developing nations as resources dwindle and coastlines are increasingly swallowed up by rising seas.
World Bank President Jim Yong Kim also warned in an advisory that a change of just 2 degrees Celsius, which many scientists believe to be unavoidable in the next 20-30 years, "will cause widespread food shortages, unprecedented heat waves, and more intense cyclones."
Hansen's report comes at a crucial time for global climate negotiators too, who are anticipating the Intergovernmental Panel on Climate Change's latest assessment of warming trends, set to be released later this month. Drafts of the report have already leaked to key climate skeptics, who've had a run of the mainstream media narrative on the matter in recent weeks. Hansen, however, pays little mind to the deniers and concludes his latest study with forceful clarity.
"If fossil fuels were made to pay their costs to society, costs of pollution and climate change, carbon-free alternatives might supplant fossil fuels over a period of decades," Hansen et. al write. "However, if governments force the public to bear the external costs and even subsidize fossil fuels, carbon emissions are likely to continue to grow, with deleterious consequences for young people and future generations."
"It seems implausible that humanity will not alter its energy course as consequences of burning all fossil fuels become clearer," the study concludes. "Yet strong evidence about the dangers of human-made climate change have so far had little effect. Whether governments continue to be so foolhardy as to allow or encourage development of all fossil fuels may determine the fate of humanity."
Hansen did not respond to a request for comment.
Photo credit: NASA Goddard Space Flight Center on Flickr, creative commons licensed.
Disclosure: Stephen C. Webster is a member of Al Gore's Climate Reality Project.