Roughly 40 percent of adults worldwide have never heard of climate change, according to an analysis of global climate change awareness and risk perception published in Nature Climate Change. The percentage of people unaware of climate change rises to more than 65 percent in developing countries such as Egypt, Bangladesh, and India, whereas only 10 percent of the public is unaware in North America, Europe, and Japan. The findings indicate that strategies for securing public engagement in climate issues will vary from country to country, the researchers say, because different populations perceive climate-related risks very differently. In many African and Asian countries, for example, climate risk is most strongly perceived through noticeable changes in local temperatures. “The contrast between developed and developing countries was striking,” said Anthony Leiserowitz, director of the Yale Program on Climate Change Communication and co-author of the study.