Although the average legal immigrant or illegal alien in the U.S. produces an estimated 18 percent less CO2 emissions than the average native-born American, immigrants and illegal aliens residing in the U.S. produce an estimated four times more CO2 here than they would have in their home countries. By residing in the U.S., immigrants and illegal aliens produce an estimated 637 million tons of CO2 annually, but they would have produced 155 million tons -- 482 million tons less -- if they had not moved here. These figures would have been higher if the study had factored in the impact of children born here to immigrants.
The study estimates that five percent of the increase in annual world-wide CO2 emissions since 1980 is attributable to U.S. immigration. Moreover, the 482 million extra tons of global CO2 emissions produced by U.S. immigration would rank 10th in the world in emissions if it were a separate country.
CIS notes its research confirms what some involved in the global-warming issue are saying about the impact of immigration. Chief U.S. climate negotiator Harlan Watson, for example, has said that high immigration to the United States is an impediment to efforts to reduce national and world CO2 emissions.