Economists, Like Scientists, Agree on Climate
January 4, 2016
You’ve heard about the 97 percent. Did you know about the 95 percent (of economists?)
In the 2015 survey, the number of expert economists saying that the US should cut its emissions no matter what rose to 77%. A further 18% said that if other countries agree to cut their emissions, the US should follow suit. In other words, there is a 95% consensus among expert climate economists that the US should follow through with its pledges to cut carbon pollution in the wake of the Paris international climate negotiations, and more than three out of four agreed that the US should take action to curb global warming no matter what.
This expert consensus is in stark contrast to conservative political opposition to the Paris accord. For example, Republican presidential candidate Marco Rubio said of the agreement,
This kind of unilateral disarmament in our economy is reckless, and it is hurting the American Dream
Quite obviously an international agreement made by 195 nations around the world is the antithesis of unilateral action. However, 77% of expert economists agree that unilateral action would be appropriate in any case, directly contradicting Rubio’s comments. Additionally, 82% of the experts agreed that by implementing climate policies, the US could strategically induce other countries to cut their carbon pollution.
Climate change is already hurting the global economy
When asked at what date climate change will have a net negative impact on the global economy, the median survey response was 2025. In the recent past, climate change likely had a net positive impact on the global economy, due primarily to the effect of carbon fertilization on crops and other plant life. However, even contrarian economists agree, when accounting for the vulnerability of poorer countries to climate impacts, global warming has been hurting the global economy since about 1980.
• Experts on the economics of climate change expressed higher levels of concern about climate change impacts than the general public, when asked identical survey questions.• Economic experts believe that climate change will begin to have a net negative impact on the global economyvery soon – the median estimate was “by 2025,” with 41% saying that climate change is already negativelyaffecting the economy.• Respondents believe that numerous sectors of the U.S. economy will be harmed by climate change. A majoritypredicted negative impacts on agriculture (94%), fishing (78%), utilities (electricity, water, sanitation – 74%),forestry (73%), tourism/outdoor recreation (72%), insurance (66%), and health services (54%).• More than three-quarters of respondents believe that climate change will have a long-term, negative impact on the growth rateof the global economy.• More than 80% 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.• Respondents overwhelmingly support unilateral emissions reduction commitments by the United States, regardless of the actions other nations have taken (77% chose this option over alternatives such as committingonly if multilateral agreements are reached).
• The vast majority (75%) of respondents believe that the most economically efficient way for states to comply with the U.S. Environmental Protection Agency’s “Clean Power Plan” carbon regulations is through “market-based mechanisms coordinated at a regional or national level (such as a regional/ national trading program or carbon tax).”• The discounting approach that the U.S. government currently uses to analyze climate regulations andother policies – a constant discount rate calibrated to market rates – was identified by experts as the least desirable approach for setting discount rates in the context of climate policies. Nearly half (46%) ofrespondents favored an approach that featured declining discount rates, while 44% favored using ratescalibrated with ethical parameters.• On average, economic experts predicted far higher economic impacts from climate change than the estimates found in older surveys of economists and other climate experts. Respondents predicted a global GDP loss of roughly 10% 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% likelihood that this same climate scenario would lead toa “catastrophic” economic impact (defined as a global GDP loss of 25% or more).•Our findings revealed a strong consensus (69%) that the “social cost of carbon” should be greater than or equal to the figure currently used by the U.S. government (only 8% believe the value should be lower).