Human activities that pump so much carbon dioxide into the atmosphere are often blamed for global warming, a phenomenon feared to cause the rising of sea levels, drought, extreme weather conditions and spread of infectious diseases.
Findings of a new study, however, suggest that emission of carbon dioxide into the atmosphere also has a beneficial effect. The new research showed that climate change alters global cycles to the extent that it has delayed the next ice age by thousands of years.
For their study published in the journal Nature on Wednesday, researchers simulated past ice ages and found a relationship among the amount of energy that Earth absorbs from the sun, glacial cycles and concentrations of carbon dioxide.
By looking at past ice ages and using a computer model of Earth that also predicts their occurrence, the researchers found that even if the emission of carbon dioxide abruptly stops, the next ice age would still be postponed by about 50,000 years. This is due to the combined effect of carbon dioxide concentrations before the Industrial Revolution and Earth's low orbital eccentricity.
Carbon dioxide in the atmosphere traps heat and thus causes a warming effect, which will occur no matter where the planet is in its orbital cycles. Sufficient amount of atmospheric carbon dioxide can counteract these cycles from making and unmaking ice ages.
The impact of greenhouse gases on the planet is long lasting because they can stay in the atmosphere for centuries, during which they can affect the evolution of the Northern Hemisphere's ice sheet. The ice gradually builds up over thousands of years through a mechanism of increasing snowfall, cooling temperatures, falling temperatures and increasing levels of sunlight.
Study researcher Andrey Ganopolski, from the Potsdam Institute for Climate Impact Research, said that while it can be mind-boggling to think that mankind is capable of interfering in a mechanism that shapes the planet, their study shows that emission of carbon dioxide from burning of coal, oil and gas are enough to postpone the next ice age by 50,000 years.
"Our analysis suggests that even in the absence of human perturbations no substantial build-up of ice sheets would occur within the next several thousand years and that the current interglacial would probably last for another 50,000 years," the researchers wrote in their study. "However, moderate anthropogenic cumulative CO2 emissions of 1,000 to 1,500 gigatonnes of carbon will postpone the next glacial inception by at least 100,000 years."