A single carbon emission takes about 10 years to achieve its greatest effect on the atmosphere, refuting ideas that greenhouse gases take decades to cause damage.
Carnegie Institution for Science researchers examined individual emissions of greenhouse gases, in order to examine the time period over which the chemicals exerted their greatest effect on the atmosphere.
"CO2 emissions cause global temperatures to increase for about a decade, but then temperatures stay high for a long time. This means if we avoid an emission, we avoid heating that would otherwise occur this decade. This will benefit us and not just our grandchildren. This realization could help break the political logjam over policies designed to reduce greenhouse gas emissions," Ken Caldeira of the Carnegie Institution for Science said.
Most climate models examine environmental changes as they occur over several decades or centuries, encompassing greenhouse gas emissions from a multitude of sources. This study focused examinations on single sources, timed in a single release. This allowed researchers to examine, for the first time in great detail, the time scale of climatic effects of the gas.
A pair of computer models were merged to develop the new model. One of these, utilized by the Intergovernmental Panel on Climate Change, studied how carbon affects the global climate. The other model examined how carbon emissions interact with the carbon cycle of the Earth. This study accounted for natural carbon "sinks," including those in the ocean and biological processes that can store carbon for long periods.
The 10-year delay from emission to maximum effect is due to carbon dioxide being absorbed into the water before heating resumes.
Time scales of around a decade for effects of carbon dioxide suggest environmental changes taken today could be felt within the lifetime of most people. This would benefit not just the children and grandchildren of people alive today, but would bring more-immediate benefits, the study suggests.
"A lot of climate scientists have intuition about how long it takes to feel the warming from a particular emission of carbon dioxide. But that intuition might be a little bit out of sync with our best estimates from today's climate and carbon cycle models," Katharine Ricke of Carnegie, said.
Researchers point out that although atmospheric effects from carbon dioxide appears to peak within a decade, damage from the emissions can last much longer. These include changes to ecosystem, loss of species, and increased sea levels.
The timescale of the effect of carbon dioxide was profiled in the journal Environmental Research Letters.
