What respiratory problems may occur from increasing carbon dioxide levels?
Dan answers: Carbon dioxide does not directly cause respiratory problems at the levels expected to occur in the atmosphere. Global warming, however, can enhance smog formation, which would cause respiratory problems. Also, the same sources that release global warming pollution — most importantly automobiles and power plants — also release large quantities of nitrogen oxide and sulfur oxide emissions which cause smog and respiratory problems. Did the global temperature increase level off from 1940 to 1970 because of particulates? If so, why has the increase now continued? Dan answers: Observed changes in global temperature over the last century result from a combination of many factors, including greenhouse gases, particulate matter, small changes in the output of the sun, and natural variability. Increases in carbon dioxide and other greenhouse gases is the only credible explanation for the overall warming trend seen in the record. The explanation of some of the details of the record
