An opinion poll conducted on the eve of 190-nation talks in Copenhagen has shown that global concern about climate change has decreased in the past two years. According to the Nielsen/Oxford University survey, 37 percent of over 27,000 Internet users in 54 countries said they were "very concerned" about climate change, down from 41 percent in a similar poll two years ago. The decline in concern was attributed to the world economic slowdown, with the United States also showing a decrease in the number of people very concerned about climate change. President Barack Obama is aiming to reduce US greenhouse gas emissions, primarily from the burning of fossil fuels, and is planning to attend a meeting in Copenhagen with over 100 other world leaders in an effort to negotiate a new UN deal. China, the leading emitter of greenhouse gases, saw an increase in the percentage of people who are very concerned about climate change, rising from 30% to 36%. The survey showed that Latin America and Asian-Pacific countries had the highest levels of concern, with the Philippines at the top with 78% following Typhoon Ketsana in September. Africa was not included in the poll. Eastern Europe had the lowest levels of concern regarding global warming caused by human emissions of greenhouse gases from burning fossil fuels. Estonia ranked lowest with only 10 percent expressing high levels of concern. According to Jonathan Banks, Business Insights Director Europe at the Nielsen Co., worries about climate change may be increasing due to the upcoming focus on Copenhagen. Economic problems had temporarily shifted attention away from climate change, but as the recession subsides, the Copenhagen summit is expected to bring this issue back to the forefront. The survey revealed that globally, air and water pollution, followed by climate change, were the top three environmental concerns for people around the world.