CHICAGO - A survey on climate change conducted in more than a dozen countries found that a majority of people in nations including South Korea, Australia, Iran and Mexico - but not the United States - view global warming as a critical threat.

In the U.S., about 46 percent of those questioned said global warming is critical, while four in 10 labeled it “an important but not critical threat,” in the survey conducted by The Chicago Council on Global Affairs and WorldPublicOpinion.org, in cooperation with other polling organizations.

Among the other countries where the question was asked, the Ukraine was the only nation where less than four in 10 participants found global warming to be a critical threat. There, it was 33 percent.

The polling was conducted last year, with field periods varying from June to December. More than 20,000 people were polled. The margin of error ranged between 3 and 4 percent.

The survey, which was released Tuesday, was first conducted in the United States, China and India. When organizations in other countries expressed interest, the effort was expanded, said Steven Kull, an editor at WorldPublicOpinion.org who took the lead in managing and analyzing the poll results.

The survey was conducted in 17 countries plus the Palestinian territories - a total area representing more than 55 percent of the world's population. Not all questions were asked in all countries.

Kull said he was struck by the widespread concern over climate change.

“If you think about the fact that just two decades ago, hardly anyone knew what climate change or global warming was, and now you have people all around the world - even in developing countries - really absorbing that there is something to address here,” Kull said. “It's really quite phenomenal that this kind of change can happen.”

Another set of questions found strong support from residents in the United States, Poland and the Ukraine for the idea that developed countries should provide substantial aid to developing countries that commit to limiting their greenhouse gas emissions.

On the flip side, the idea that developing countries should commit to limiting their emissions if developed countries were willing to provide aid was strongly supported in Armenia and China; in India 48 percent polled favored such a proposal, but 23 percent declined to answer.

On a question that polled whether immediate steps should be taken to combat global warming even if it involves “significant costs,” the strongest support was found in Australia (69 percent of those responding), Israel (54 percent), the United States (43 percent) and China (42 percent).