New Yale-led research reveals for the first time what the world thinks about climate change and why.

Using data from the 2007-2008 Gallup World Poll, conducted in 119 countries, an international team of researchers identified the factors that most influence climate change awareness and risk perception for 90% of the world’s population.

The contrast between developed and developing countries was striking, note the researchers: In North America, Europe, and Japan, more than 90% of the public is aware of climate change. But in many developing countries, relatively few are aware of the issue, although many do report having observed changes in local weather patterns.

The study was published in the journal Nature Climate Change on July 27.

“Overall, we find that about 40% of adults worldwide have never heard of climate change,” said co-author Anthony Leiserowitz, director of the Yale Project on Climate Change Communication and study lead. “This rises to more than 65% in some developing countries, like Egypt, Bangladesh, and India.”

The research team also found that education level tends to be the single strongest predictor of a person’s awareness of climate change. However, the research reveals some stark differences between countries. In the United States, the key predictors of awareness are civic engagement, communication access, and education. Meanwhile in China, climate change awareness is most closely associated with education, proximity to urban areas, and household income.