Most Americans agree that climate change is occurring, but they disagree about the causes and tend to base their opinions upon their politics rather than upon scientific knowledge. This tendency, recently reported in survey-based research from the Carsey Institute at the University of New Hampshire, is referred to as “biased assimilation”: “Most people gather information about climate change not directly from scientists but indirectly, for example through news media, political activists, acquaintances, and other non-science sources. Their understanding reflects not simply scientific knowledge, but rather the adoption of views promoted by political or opinion leaders they follow. People increasingly choose news sources that match their own views. Moreover, they tend to selectively absorb information even from this biased flow, fitting it into their pre-existing beliefs. This ‘biased assimilation’ has been demonstrated in experiments that find people reject information about the existence of a problem if they object to its possible solutions (Carsey Institute Issue Brief No. 26 by Lawrence C. Hamilton, Spring 2011)
In 2010 and early 2011, Carsey Institute researchers conducted 10 surveys involving 9,489 interviews in seven different regions of the United States that included three questions about climate change: “We asked how much people understand about the issue of global warming or climate change; whether they think that most scientists agree that climate change is happening now as a result of human activities; and what they believe personally about the topic. The questions are neutrally worded, concern beliefs about present facts rather than possible future events, and address the main point of statements made by scientists.” Key findings include:
- Most people say that they understand either a moderate amount or a great deal about the issue of global warming or climate change.
- Large majorities agree that climate change is happening now, although they split on whether this is attributed mainly to human or natural causes.
- The level of understanding about climate change varies considerably by region.
- Beliefs about climate change are strongly related to political party. Republicans most often believe either that climate is not changing now or that it is changing but from mainly natural causes. Democrats most often believe that the climate is changing now due mainly to human activities.
- Political polarization is greatest among the Republicans and Democrats who are most confident that they understand this issue. Republicans and Democrats less sure about their understanding also tend to be less far apart in their beliefs.
- People who express lower confidence also might be more likely to change their views in response to weather.
“If the scientists are right, evidence of climate change will become more visible and dramatic in the decades ahead. Arctic sea ice, for example, provides one closely watched harbinger of planetary change. In its 2007 report the IPCC projected that late-summer Arctic sea ice could disappear before the end of the 21st century. Since that report was written, steeper-than-expected declines have led to suggestions that summer sea ice might be largely gone by 2030, and some think much sooner. We will find out in time — either the ice will melt, or it won’t. The Arctic Ocean, along with other aspects of the ocean-atmosphere system, presents an undeniable physical reality that could become more central to the public debate. In the meantime, however, public beliefs about physical reality remain strikingly politicized.”
