Increased global warming caused by cloudsDate: 28 June 2020 Tags: Climate Change
A new study for understanding global warming indicates the reason is likely related to challenges simulating the formation and evolution of clouds.
Clouds have a complicated relationship with climate warming – certain types of clouds in some locations reflect more sunlight, cooling the surface, while others can have the opposite effect, trapping heat.
Compared with older models, these updated models has shown higher sensitivity to carbon dioxide – that is, more warming for a given concentration of the greenhouse gas.
If the models on the high end are correct and Earth is truly more sensitive to carbon dioxide than scientists had thought, the future could also be much warmer than previously projected.
Researchers have observed that interaction between clouds and tiny particles called aerosols in particular, seem to be contributing to higher sensitivity.
Researchers have traditionally evaluated climate model sensitivity using two different metrics. The first, which has been in use since the late 1970s, is called equilibrium climate sensitivity (ECS).
It measures the temperature increase after atmospheric carbon dioxide is instantaneously doubled from preindustrial levels and the model is allowed to run until the climate stabilizes.
Aerosols, which can be emitted naturally from volcanoes and other sources as well as by human activity, also reflect sunlight and have a cooling effect.
But they interact with clouds too, changing their formation and brightness and, therefore, their ability to heat or cool the surface.