Experts on the economics of climate change have revealed concerns that damages from climate change impacts will be larger and more immediate than previously estimated, according to a new survey from The Institute for Policy Integrity at New York University School of Law.
The survey’s respondents were limited to those who have published an article about food production, climate adaptation, energy economics and other topics related to climate change in a highly ranked, peer-reviewed economics journal since 1994.
The report, Expert Consensus on the Economics of Climate Change, says climate change will begin to have a net negative impact on the global economy very soon. The median estimate was “by 2025,” with 41 percent saying that climate change is already negatively affecting the economy.
On average, economic experts predicted far higher economic impacts from climate change than the estimates found in older surveys. Respondents predicted a global GDP loss of roughly 10 percent if global mean temperature increases by 3°C relative to the pre-industrial era by 2090 — this increase approximates a “business as usual” emissions scenario.
Experts believe that there is greater than a 20 percent likelihood that this same climate scenario — defined as a global GDP loss of 25 percent or more — would lead to a “catastrophic” economic impact.
Respondents overwhelmingly support unilateral emissions reduction commitments by the United States, regardless of the actions other nations have taken. Some 77 percent chose this option over alternatives such as committing only if multilateral agreements are reached. More than 80 percent of experts believe that the United States may be able to strategically induce other nations to reduce their greenhouse gas emissions by first adopting policies to reduce U.S. emissions.
Other survey questions focused on how climate change will affect specific sectors of the U.S. economy; how it will alter the economic growth rate; how states can most efficiently comply with the EPA’s Clean Power Plan; and other topics.
With world leaders amid the second and final week of COP21 in Paris discuss a global climate agreement, this new survey suggests the economic stakes are even higher than previously estimated.
Even if the proposed climate agreement is reached, there will be a significant gap in those actions and what will be needed to keep the planet cool enough to avoid the worst climate change impacts. Cities may be able to help fill this “emissions gap,” according to a new C40 report. If cities around the world take aggressive climate change action, they can help cut global emissions by 3.7 billion tons a year by 2030.