Climate Change

Trends & Patterns

The distribution of the world’s rainfall is shifting as our climate changes. Wet areas may become wetter, dry areas drier, storms more intense, leading to more chaotic weather around the world. According to the Intergovernmental Panel on Climate Change (IPCC, 2011), an increase in the average global temperature is very likely to lead to changes in precipitation and atmospheric moisture, including shifts towards more extreme precipitation during storms.

As the lower atmosphere (the troposphere) becomes warmer, evaporation rates increase, which leads to an increase in the amount of moisture circulating. When the troposphere has more moisture, more intense precipitation occurs, thus potentially triggering more flooding over land.  Conversely in other areas, warmer temperatures may lead to increased drying accelerating the onset of drought.

Map showing global rainfall averages from 1998 - 2010, using TRMM precipitation data.
Global rainfall averages from 1998-2010, compiled from TRMM precipitation data.

To predict future changes in climate, scientists use very sophisticated computer models that rely on available global data to describe climate as it is today and project how it may behave in the future. The key information offered by both TRMM and GPM helps scientists more accurately estimate the rate of water transfer within the Earth's atmosphere and on the surface. It also reconciles the different parts of the overall water budget. By providing measurements of surface water fluxes, cloud/precipitation microphysics and latent heat release in the atmosphere, GPM advances Earth system modeling and analysis. More accurate global precipitation estimates improve the accuracy and effectiveness of climate models and advance understanding of climate sensitivity and future climatic change.