Carbon dioxide discharged by coal-fired power plants and fossil-fueled vehicles has been causing hundreds of premature US deaths each year.

The deaths were due to lung and heart ailments linked to ozone and polluting particles in the air, which are spurred by carbon dioxide that comes from human activities, according to the study's author, Mark Jacobson of Stanford University.

As the planet warms due to carbon dioxide emissions, the annual death rate is forecast to climb, with premature deaths in the United States from human-generated carbon dioxide expected to hit 1,000 a year when the global temperature has risen by 1.8 degrees When the planet gets that hot, which could happen this century.

The world annual death rate is estimated to rise to 21,600, Jacobson said on Friday in a telephone interview.

Earth has warmed about 1.4 degrees F (0.8 degrees C) in the last 150 years, with most of that gain in the last three decades. Jacobson said about 700 to 800 U.S. annual deaths in the most recent years can be attributed to human-caused carbon emissions.

Carbon dioxide is one of several greenhouse gases blamed for climate change, but it is the one human have the most ability to control through regulation of activities that burn fossil fuels like coal and oil. It is also emitted by natural processes.

SG/HAR