Marc Airhart said on March 14, 2011 at 10:39 a.m. Joseph, thanks for writing. As I understand it -- and I have to stress I'm not an expert on volcanic effects on climate -- following the Mount Pinatubo eruption in the early 1990s, global temperatures dipped for a year or two due to increased sulfate aerosols in the atmosphere reflecting more solar radiation back to space. Sure, some heat was released into the air from the volcano, but climatologists I've talked to say the cooling effect far outweighed any release of heat.
Joseph Oruoch said on Feb. 4, 2011 at 6:17 a.m. Volcanism is the only credible cause of climate change. The heat that warms the temperatures around the earth comes from within the earth and not the sun. When pressure builds within the earth then more heat diffuses from the mantle through the crust into the surrounding atmosphere causing global warming. But sometimes the pressures inside the earth becomes too much thereby cracking the crust and causing volcanic eruption. During a volcanic eruption the earth looses some of its heat rapidly and directly into the atmosphere meaning that the gradual heat that comes out through diffusion reduces and allows the global temperatures to cool. This regulates global temperatures causing both global warming and cooling. For further details on how this happens please go to http://www.climatechange.epitomeillustrations.com.