For Earth Day: Two-thirds of Americans Believe Humans are Contributing to Increased Temperatures

As the nation gets ready to celebrate Earth Day 2008, attitudes towards global warming are little changed from last year. Two-thirds (67%) of Americans believe the activities of human beings are contributing to an increase in global temperatures. This is little changed from last year when 65 percent of Americans believed this. Last year, one in five (21%) Americans said they did not believe the activities of humans contributed to an increase in temperatures while this year 17 percent do not believe this.

These are some of the results of a nationwide Harris Poll of 2,529 U.S. adults surveyed online between April 7 and 15, 2008 by Harris Interactive^®.

Where there has been a change is in feelings towards the amount of the increase in temperatures. Last year half (50%) of those who believe humans are contributing to an increase in temperatures characterized that increase as substantial; this year 40 percent say it is substantial. Just under this (38%) believe the change is moderate, while one-third (33%) said it was moderate last year. One in five (18%) say the increase is slight, while 14 percent said slight last year.

The impact of global warming is not one that people believe will be a threat to them or their families soon. Three in ten (30%) Americans believe global warming will present a threat to them and their families within their lifetime while 39 percent believe it will not and almost one-third (31%) are not sure. Last year, over one-third (36%) believed it would be a threat within their lifetime while 41 percent said it would not and one-quarter (24%) were not sure.

One thing that has been discussed a lot recently is a carbon footprint. Everyone has one, but do people know what their footprint is? Probably not, as only one in ten (11%) Americans say that they have gone and looked up their personal and/or household’s carbon footprint. The younger people are, the more likely they have looked up their footprint. Almost one in five (18%) Echo Boomers (those aged 18-31) say they have looked up their carbon footprint and/or their household’s footprint as have 11 percent of Gen Xers (those aged 32-43) compared to just 9 percent of Baby Boomers (those aged 44-62) and 6 percent of Matures (those aged 63 and older).

While people may not be looking up their carbon footprint, Americans claim that they are doing things that will reduce it and their carbon emissions. Almost two-thirds (63%) of Americans say they may have reduced the amount of energy they use in their home, while two in five (43%) have purchased more energy efficient appliances. Additionally, over one-quarter (27%) of Americans have started purchasing more locally grown food while one in five (21%) have stopped drinking bottled water. Much smaller numbers (2% each) have purchased a hybrid car or purchased carbon offsets from an organization.

While most people are doing something, one-quarter of adults (27%) are doing nothing to reduce their emissions. And, while younger Americans may be more likely to look up their carbon footprint, they are also more likely to do nothing about it. Three in ten Echo Boomers (29%) and Gen Xers (31%) say they are doing nothing to reduce their emissions compared to one-quarter (26%) of Baby Boomers and one in five (20%) Matures.

Experience suggests that we should be somewhat skeptical of claims people make about doing the "right thing". Energy consumption continues to increase so whatever actions people are taking are probably modest ones. However, the fact that so many people feel that reducing their own carbon emissions and/or footprint is important is encouraging.

"Thinking about climate change, do you believe that the activities of human beings are contributing to an increase in global temperatures?"

Base: All adults

Note: Percentages may not add up exactly to 100% due to rounding.

"Would you characterize this increase in global temperatures as slight, moderate or substantial?"

Base: Believe humans contributing to increased global temperatures

Note: Percentages may not add up exactly to 100% due to rounding.

"Will global warming present a threat to you and your family within your lifetime?"

Base: All adults

Note: Percentages may not add up exactly to 100% due to rounding.

"Have you ever looked up what your personal or your household’s carbon footprint is? By carbon footprint, we mean the total amount of carbon dioxide emitted by an individual or a household."

Base: All adults

Note: Percentages may not add up exactly to 100% due to rounding.

"Which of the following have you done in an attempt to offset your carbon footprint or reduce your emissions?"

Base: All adults

This Harris Poll^® was conducted online within the United States between April 7 and 15, 2008, among 2,529 adults (aged 18 and over). Figures for age, sex, race, education, region and household income were weighted where necessary to bring them into line with their actual proportions in the population. Propensity score weighting was also used to adjust for respondents’ propensity to be online.

All sample surveys and polls, whether or not they use probability sampling, are subject to multiple sources of error which are most often not possible to quantify or estimate, including sampling error, coverage error, error associated with nonresponse, error associated with question wording and response options, and post-survey weighting and adjustments. Therefore, Harris Interactive avoids the words "margin of error" as they are misleading. All that can be calculated are different possible sampling errors with different probabilities for pure, unweighted, random samples with 100% response rates. These are only theoretical because no published polls come close to this ideal.

Respondents for this survey were selected from among those who have agreed to participate in Harris Interactive surveys. The data have been weighted to reflect the composition of the adult population. Because the sample is based on those who agreed to participate in the Harris Interactive panel, no estimates of theoretical sampling error can be calculated.

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