Earth to warm even if greenhouse gas cut - US study

If nations cut back on emissions, it will not heat up as much, but it will still be hotter than it is now, according to a computer climate model. \"Some continued global warming will occur ... even if the greenhouse gases in the air do not increase further, but the warming could be much less than the worst-case scenarios,\" lead researcher James Hansen said in a statement. If emissions continue to increase at the current rate, global temperatures may increase by 2-4 degrees Fahrenheit (1-2 Celsius) the study found. But if carbon dioxide emissions do not increase any faster than they are now and if nations cut emissions of true air pollutants - those harmful to humans - temperatures might only rise 1.4 degrees Fahrenheit (.75 Celsius). The climate model provided a convincing demonstration that global temperature change of the past half-century was mainly a response to climate forcing agents, or imposed perturbations of the Earth\'s energy balance, researchers found. This was especially true of human-made forcings, such as carbon dioxide and methane, which trap the Earth\'s heat radiation as a blanket traps body heat. Hansen is based at NASA\'s Goddard Institute for Space Studies in New York City, but the research was a collaborative effort among 19 institutions, including seven universities, federal agencies, private industry and other NASA centers, and was funded by NASA. The results appear in the current Journal of Geophysical Research-Atmospheres. REUTERS NEWS SERVICE