Eighteen prominent international climate scientists and economists have authored a paper that seeks to answer the most vexing environmental question facing the planet: How to reverse soaring carbon dioxide emissions and prevent the world from experiencing destabilizing climate change.
Their answer, presented in the journal PLOS One, boils down to this: Offer global leaders a detailed blueprint for decarbonization that involves setting a steadily rising price on carbon, the large-scale deployment of nuclear power and renewable energy, increased research into low-carbon energy technologies, and a reform of forestry and agricultural policies that leads to massive sequestration of CO2 — all while not spending more than 1 percent of global gross economic output.
“In terms of economics, comparing a path to decarbonization versus a path of wrecking the planet are not even close,” economist Jeffrey Sachs, a co-author of the paper and director of Columbia University’s Earth Institute, said at a press briefing. “We haven’t shown the path of decarbonzation clearly enough (and) what the real choices are.”
The lead author of the paper is James Hansen, former director of NASA’s Goddard Institute for Space Studies and now a scientist at the Earth Institute. His co-authors include scientists ranging from glaciologist Konrad Steffen of the Swiss Federal Institute of Technology to biologist Camille Parmesan of the University of Texas. A key conclusion of the paper is that a benchmark goal set by international climate negotiators — holding future temperature increases to 2 degrees C (3.6 degrees F) above pre-industrial levels — is too high and could lead to severe climate disruption. This includes intensifying melting of polar ice sheets, eventual sea level increases of 20 feet, global ecological shifts, and more powerful hurricanes, cyclones, and other storms, the paper says.
According to the paper, policymakers should aim to hold temperature increases to 1 degree C (1.8 degrees F) above pre-industrial levels, a highly ambitious goal that would require limiting total cumulative human CO2 emissions to 500 billion metric tons. To date, human activity has emitted 370 billion tons and is adding nearly 10 billion tons a year to the atmosphere. The paper also calls for new forestry and agriculture policies that would lead to the sequestration of 100 billions tons of carbon into the biosphere and the soil. The Intergovernmental Panel on Climate Change recently said that to keep temperature increases below 2 degrees C, the world’s economies could emit a cumulative total of 1 trillion tons of carbon — twice the level recommended by Hansen and his colleagues.
The paper’s key recommendation is a gradually increasing price on carbon that would reflect the true price to the global economy and environment of continuing to combust fossil fuels. Hansen said at the press briefing that although the increased deployment of solar, wind, and other renewable energy technologies is vital, the fact remains that after several decades of renewable energy subsidies, such technologies only account for 2 percent of the world’s energy mix. That does not even equal the current annual growth of fossil fuel usage, Hansen said. He suggested that widespread deployment of “third- and fourth-generation” nuclear power plants is essential to slashing carbon emissions.
Sachs stressed that none of the world’s major economies have developed detailed, realistic decarbonization plans, which has led to stalemate at global climate talks. Such plans, he said, would include significant increases in the research and development of “low carbon” energy, including nuclear power; achievable targets for switching the transportation sector and heating and cooling of buildings to low-carbon sources of electricity; and a price on carbon that would reward companies and individuals for sharply reducing fossil fuel use. California, he said, has embarked on such a path, with a target of reducing its carbon emissions by 80 percent by 2050.
“Simply issuing warnings will not solve the problem at all — people want solutions, not warnings,” Sachs said at the briefing at Columbia University. “Until we have a lot more clarity spelled out, which I think can be done, the politics will get stuck . . . because the public wants to know what does it mean for our lives? Is it safe? Is it compatible with our economic aspirations? The answer is actually, `Yes.’ The fundamental reason for optimism is that you can discern an alternative that makes sense, that addresses the problem of scale, and that is low-cost in the sense of being on the order of 1 percent (of global GDP). The underlying rationale is overwhelming — at low cost, it’s possible to avoid the devastating risks of a continued business-as-usual path.”
Article by Fen Montaigne, appearing courtesy Yale Environment 360.