As part of the international CLOUD project at the nuclear research center CERN, researchers at PSI have identified so-called sesquiterpenes—gaseous hydrocarbons that are released by plants—as being a major factor in cloud formation. This finding could reduce uncertainties in climate models and help make more accurate predictions. The study has now been published in the journal Science Advances.
According to the latest projections of the Intergovernmental Panel on Climate Change (IPCC), the global climate will be 1.5 to 4.4 degrees Celsius warmer than pre-industrial levels by 2100. This figure is based on various scenarios describing how anthropogenic greenhouse gas emissions may develop in the future. So in the best case, if we manage to curb emissions quickly and radically, we can still meet the 1.5 degree target of the Paris Agreement.
In the worst case, we will end up far above that. However, such projections are also subject to some uncertainty. In the worst-case scenario, for example, with emissions continuing to increase sharply, the rise in temperature could be as low as 3.3 or as high as 5.7 degrees Celsius, rather than 4.4 degrees.
These uncertainties in predicting how temperatures will change as a result of concrete developments in greenhouse gas emissions are essentially due to the fact that scientists do not yet fully understand all the processes that occur in the atmosphere—the interactions between the various gases and aerosols in it. Establishing them is the aim of the CLOUD project (Cosmics Leaving Outdoor Droplets), an international collaboration between atmospheric researchers at the CERN nuclear research center in Geneva. PSI helped to build the CLOUD chamber and is a member of the project’s steering committee.
Particularly the way in which cloud cover will develop in the future remains largely nebulous for the time being. However, this is a key factor in predicting the climate because more clouds reflect more solar radiation, thus cooling the earth’s surface.
2023-09-08 18:48:02
Post from phys.org rnrn