On Monday, Rep. Paul Ryan (R-WI) reiterated that he doesn’t think climate change is worth fighting, or that human beings are to blame.
Ryan is running for re-election in his Wisconsin district against Democratic challenger Rob Zerman. According to a report by the Associated Press, the question of humanity’s responsibility for climate change came up during a debate on Monday between the two. “I don’t know the answer to that question,” Ryan said, when the moderator pressed each candidate on the topic. “I don’t think science does, either.”
Ryan also asserted that “we’ve had climate change forever,” and that the benefits of policies to cut carbon emissions “do not outweigh the costs.”
This is not Paul Ryan’s first go-round on the issue: back in July, the Congressman dismissively said that “climate change occurs no matter what,” and that efforts by the Environmental Protection Agency to reduce greenhouse gas emissions from power plants are “an excuse to grow government, raise taxes and slow down economic growth.” For his part, Zerban said Monday night that climate change is both serious and man-made, according to the Associated Press’ story — but that it also presents an opportunity for the United States to invest in renewable sources of energy.
As for the substance of Ryan’s arguments, it’s worth addressing each.
On the first point — and to paraphrase several of Ryan’s Republican colleagues — the Congressman from Wisconsin is not a scientist. Specifically, he’s not climate scientist. But there are, in fact, many, many climate scientists out there who have studied climate change in detail. And 97 percent of them agree human carbon emissions are a major driver of climate change.
Furthermore, the United Nations’ Intergovernmental Panel On Climate Change (IPCC) — the single biggest international effort to collect and summarize scientific knowledge on climate change — has found a 95 percent certainty that humanity’s greenhouse gases are responsible for the vast majority of observed global warming since the 1950s. (That’s the same level of certainty scientists attach to the idea that cigarettes kill.) Thanks to ice core samples and other evidence, scientists have been able to reconstruct historical temperatures going back many thousands of years — and the data show temperatures plateauing about ten thousand years ago, followed by a dramatic increase in the last 200 years. That jump roughly lines up with the Industrial Revolution and the advent of mass fossil fuel use.
As for Ryan’s second claim — that “the benefits do not outweigh the costs” — there are several things that need to be unpacked here. To make this assertion, people usually draw on projections of how much climate change will reduce the size of the world’s future economy versus how much cutting carbon emissions would reduce it. But the metric here — global domestic product (GDP) — is a pinched and bloodless measure of human well-being. For example, the IPCC’s mid-range projections show a loss to global GDP of one to five percent by 2100 from continuing business-as-usual emissions. That seems small, until you consider Africa and its 1.1 billion inhabitants amount to three to five percent of GDP. “Would you rather have a one percent tax increase on everyone in the country or kill one percent of the population,” is how Trevor Houser, a key researcher in the recent Risky Business report, often puts it. “Because it’s about the same impact [on GDP].”
Modeling the combined systems of the climate and the global economy is also a devilishly complicated business, and there’s a reasonable case to be made that the IPCC, which is a conservative and consensus-based institution, is low-balling the risks by a wide margin. Climate change is ultimately a question of risk mitigation; the worst-case scenarios may be unlikely, but they would be absolutely devastating if they do occur. And because carbon dioxide is cumulative in the atmosphere, we make the worst-case scenarios a bit more likely with every ton we emit. To take a practical example, this is the whole idea behind health insurance: pay a certain price now to prevent for an outcome that, while statistically remote, would be catastrophic.
Finally, critics of efforts to cut carbon emissions and other forms of environmental pollution have a long history of wildly overstating the economic costs of such policies. Partially, this is because market economies are innovative and dynamic, and tend to tackle the challenges posed by regulations in better and more diverse ways than observers anticipate. But cuts to pollution also come with unexpected benefits to the economy, mainly in the form of healthier Americans who can then go on to produce more wealth and income. Lots of studies routinely show that these health benefits to job and economic growth significantly overtake any economic drag from regulatory compliance.
Now, not all forms of carbon emission reduction are created equal. Some are less efficient than others. But lots of economic models and real-world examples show a carbon tax, for example, would have essentially zero negative effect on the economy if the revenue it raises is plowed back into Americans’ pocketbooks through other tax cuts, dividends, or rebate checks.
But making sure a national climate policy is as efficient as possible is a reason for Paul Ryan and his fellow legislators to get in the game, rather than mindlessly repeating right-wing talking points from the sidelines.