The United States ranked poorly in a recent international environmental assessment, coming in 39th out of 149 countries. Nations were ranked according to their performance in key categories, including agriculture policies, air pollution, sanitation, greenhouse-gas emissions, and more. Countries in Europe scored well as a whole; seven of the top 10 nations were European: Switzerland, Sweden, Norway, Finland, Austria, France, and Latvia. The others in the top 10 were Costa Rica, Colombia, and New Zealand. Researchers at Yale and Columbia University, who crunched the numbers, said this year they weighted climate-change efforts more heavily than in past assessments. High greenhouse-gas emissions, combined with lingering smog problems, contributed to the U.S.’s relatively low ranking. China came in at 104th, India was ranked even lower at 120th, and Iraq came in at 134th. Niger was dead last.