Climate change opinion is the aggregate of public opinion held by the adult population. Cost constraints often restrict surveys to sample only one or two countries from each continent or focus on only one region. Because of differences among questions, wording, and methods—it is difficult to reliably compare results or to generalize them to opinions held worldwide.
In 2007–2008, the Gallup Poll surveyed individuals from 128 countries in the first comprehensive study of global opinions. The Gallup Organization aggregated opinion from the adult population fifteen years of age and older, either through the telephone or personal interviews, and in both rural and urban areas except in areas where the safety of interviewer was threatened and in scarcely populated islands. Personal interviews were stratified by population size or geography and cluster sampling was achieved through one or more stages. Although error bounds vary, they were all below ±6% with 95% confidence.
Weighting countries to a 2008 World Bank population estimate, sixty-one percent of individuals worldwide were aware of global warming, developed countries more aware than developing, with Africa the least aware. The median of people perceiving it as a threat was 47%. Latin America and developed countries in Asia led the belief that climate change was a result of human activities, while Africa, parts of Asia and the Middle East, and countries from the Former Soviet Union led in the opposite. Awareness often translates to concern, although of those aware, individuals in Europe and developed countries in Asia perceived global warming as a greater threat than others.
Unless referenced otherwise, all data is from the 2007–2008 Gallup poll mentioned earlier.