Earth’s Energy Out of Balance: The Smoking Gun for Global Warming
April, 2005

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One consequence of the ocean’s inertia and the resulting planetary energy imbalance is that there is about 1 degree Fahrenheit more global warming ‘in-the-pipeline’ – warming that will occur this century without any further increases of greenhouse gases. The Earth has already warmed, on average, about one degree Fahrenheit over the past century

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October 4, 2016

The Politics of Climate

Polarized views about climate issues stretch from the causes and cures for climate change to trust in climate scientists and their research. But most Americans support a role for scientists in climate policy, and there is bipartisan support for expanding solar, wind energy

Political fissures on climate issues extend far beyond beliefs about whether climate change is occurring and whether humans are playing a role, according to a new, in-depth survey by Pew Research Center. These divisions reach across every dimension of the climate debate, down to people’s basic trust in the motivations that drive climate scientists to conduct their research.

Specifically, the survey finds wide political divides in views of the potential for devastation to the Earth’s ecosystems and what might be done to address any climate impacts. There are also major divides in the way partisans interpret the current scientific discussion over climate, with the political left and right having vastly divergent perceptions of modern scientific consensus, differing levels of trust in the information they get from professional researchers, and different views as to whether it is the quest for knowledge or the quest for professional advancement that drives climate scientists in their work.

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At the same time, political differences are not the exclusive drivers of people’s views about climate issues. People’s level of concern about the issue also matters. The 36% of Americans who are more personally concerned about the issue of global climate change, whether they are Republican or Democrat, are much more likely to see climate science as settled, to believe that humans are playing a role in causing the Earth to warm, and to put great faith in climate scientists.

When it comes to party divides, the biggest gaps on climate policy and climate science are between those at the ends of the political spectrum. Across the board, from possible causes to who should be the one to sort this all out, liberal Democrats and conservative Republicans see climate-related matters through vastly different lenses. Liberal Democrats place more faith in the work of climate scientists (55% say climate research reflects the best available evidence most of the time) and their understanding of the phenomenon (68% say climate scientists understand very well whether or not climate change is occurring). Perhaps it follows, then, that liberal Democrats are much more inclined to believe a wide variety of environmental catastrophes are potentially headed our way, and that both policy and individual actions can be effective in heading some of these off. Even the Republicans who believe the Earth is warming are much less likely than Democrats to expect severe harms to the Earth’s ecosystem and to believe that any of six individual and policy actions asked about can make a big difference in addressing climate change. And, a majority of conservative Republicans believe that each of the six actions to address climate change can make no more than a small difference.

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To understand how it’s possible to doubt something despite evidence to the contrary, try some thought experiments. Suppose you observe a shopper at the convenience store buying a lottery ticket. You are aware that the probability that he will lose the lottery is astronomically high, typically above 99.99 percent, but it’s hard to get yourself to sincerely say you know this person will lose the lottery. Now imagine your doctor screens you for a disease, and the test comes out negative. But consider the possibility that this result is one of those rare “false negative” cases. Do you really know the result of this particular test is not a false negative?

These scenarios suggest that it’s possible to feel as though you don’t know something even when possessing enormous evidence in its favor. Philosophers call scenarios like these “skeptical pressure” cases, and they arise in mundane, boring cases that have nothing to do with politics or what one wants to be true. In general, a skeptical pressure case is a thought experiment in which the protagonist has good evidence for something that he or she believes, but the reader is reminded that the protagonist could have made a mistake. If the story is set up in the right way, the reader will be tempted to think that the protagonist’s belief isn’t genuine knowledge.

When presented with these thought experiments, some philosophy students conclude that what these examples show is that knowledge requires full-blown certainty. In these skeptical pressure cases, the evidence is overwhelming, but not 100 percent. It’s an attractive idea, but it doesn’t sit well with the fact that we ordinarily say we know lots of things with much lower probability. For example, I know I will be grading student papers this weekend. Although the chance of this happening is high, it is not anything close to 100 percent, since there is always the chance I’ll get sick, or that something more important will come up. In fact, the chance of getting sick and not grading is much higher than the chance of winning the lottery. So how could it be that I know I will be grading and not know that the shopper at the convenience store will lose the lottery?

Philosophers have been studying skeptical pressure intensely for the past 50 years. Although there is no consensus about how it arises, a promising idea defended by the philosopher David Lewis is that skeptical pressure cases often involve focusing on the possibility of error. Once we start worrying and ruminating about this possibility, no matter how far-fetched, something in our brains causes us to doubt. The philosopher Jennifer Nagel aptly calls this type of effect “epistemic anxiety.”

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