By April Garbuz, Wilton High School
With all the evidence of global warming, the question of why global temperatures remained constant during the last decade has baffled many and given climate change skeptics something to cite as evidence of global warming. But now a team of scientists led by Robert Kaufmann of Boston University has discovered why global surface temperatures did not continue to rise between 1998 and 2008. The study found that sulfur particles sent into the atmosphere by coal-burning power plants countered the effects of global warming.
While power plants in Asia emitted warming greenhouse gases, they simultaneously sent cooling sulfur particles into the atmosphere. The two types of emissions balanced one another’s effects, but altered the effects of natural cooling cycles associated with the sun and ocean temperatures.
The research team analyzed factors that contribute to global surface temperature, such as human-caused emissions, the solar cycle, and the climate patterns of warming El Niño to cooling La Niña. Naturally (without human input) temperatures would have been expected to cool, based on the La Niña shift and decreasing solar radiation. Stimulating the temperature change over the decade based on these factors, the researchers identified sulfur aerosols as the cause for the steady temperatures. Sulfur aerosols reflect light back into space and counteract the warming effects of greenhouse gases.
Kaufmann reported in the study:
“Humans do two things to the planet. They warm it by emitting greenhouse gases like carbon dioxide and methane, and they cool it by emitting these sulfur aerosols.”
Despite the cooling effects, sending sulfur into the air is not helpful. Sulfur aerosols combine with water vapor to form acid rain, which harms ecosystems, damages buildings, and causes respiratory problems. In short, further polluting the air to counter the harmful effects of other pollutants is not the solution to global warming.