Amid increasing levels of atmospheric carbon dioxide, a new study warns our planet could reach a tipping point where marine stratus clouds become unstable and disappear, which could significantly worsen global warming.
Dangerous Concentration Of Atmospheric Carbon Dioxide
In a new study published in the Nature Geoscience on Feb. 25, researchers found that the event could increase the surface temperature by about 14 degrees Fahrenheit. It may occur when carbon dioxide concentrations reach above 1,200 parts per million. Increasing levels of this greenhouse gas are largely blamed for climate change.
Carbon dioxide concentration is currently around 410, but this is increasing. If the burning of fossil fuels continues at its current rate, Earth's carbon dioxide levels may reach above 1,200 ppm in the next century.
"I think and hope that technological changes will slow carbon emissions so that we do not actually reach such high CO2 concentrations," study researcher Tapio Schneider, from California Institute of Technology said.
Stratus clouds cover about 20 percent of subtropical oceans. They cool and shade the planet as they reflect sunlight and hit them back into space. This makes them important in regulating the surface temperature of the Earth.
Schneider and colleagues created a model of the atmospheric section above a subtropical ocean then simulated the clouds and their turbulent motions over this patch of the ocean on supercomputers.
Schneider and colleagues observed instability of the cloud decks which was followed by increased warming when the levels of carbon dioxide exceeded 1,200 ppm.
They also found that once the cloud decks disappeared, they did not reappear until the concentration of carbon dioxide dropped to levels that are substantially below where the instability initially occurred.
"Climate transitions that arise from this instability may have contributed importantly to hothouse climates and abrupt climate changes in the geological past. Such transitions to a much warmer climate may also occur in the future if CO_2 levels continue to rise," the researchers wrote in their study.