This article is the first of a two-part series on views about global warming. The first focuses on awareness of the issue and its causes. The second will examine the relationship between these views and objective indicators of a nation's energy efficiency.

WASHINGTON, D.C. -- Gallup Polls conducted in 127 countries in 2007 and 2008 reveal that more than a third of the world's population has never heard of global warming. The percentage of people who report knowing "something" or a "great deal" about global warming ranged from a low of 15% in Liberia to a high of 99% in Japan. Across these 127 countries, the median percentage of people who report knowing about global warming is 62%. This leaves a worldwide median of 38% who either report having never heard about it or did not have an opinion.

Public awareness of global warming tends to be higher in highly developed countries and lower in less developed countries. In Japan and Finland, for example, nearly everyone surveyed reported knowing about global warming. However, in African countries such as Liberia and Benin, less than a quarter of people surveyed say they know about it. In fact, 16 of the 20 countries with the lowest public awareness of global warming are in Africa.

Respondents who reported knowing something or a great deal about global warming were asked about their views on the causes of global warming. Their responses reveal that public knowledge of the concept of global warming is not the same thing as the public belief that global warming is a result of human activities.

For example, Latin Americans are in the middle of the international pack in overall awareness of global warming. However, focusing on people who say they know about global warming, Latin Americans lead the world in the belief that rising temperatures across the globe (a part of global warming) are a result of human activity. In fact, 13 of the top 20 countries where more people believe global warming is a result of human activities are in Latin America.

Another example that reveals that public knowledge of the concept of global warming is not the same thing as public belief that global warming is a result of human activities is in the U.S. Despite the fact that the U.S. ranks third in overall awareness of global warming -- at 97% -- only 49% of this 97% say they think rising temperatures are a result of human activities.

The countries where fewer people believe that global warming is the result of human activities are highly dispersed. Although 8 of the 20 countries at the bottom of the world rankings are in Africa, the remaining 12 include a mixture of Asian and Middle Eastern countries, a few countries from the Former Soviet Union, and individual countries as different as Haiti and Iceland.

Click page 2 to see rankings of all 127 countries on perceptions of global warming.