The Max Planck Institute for Meteorology (MPI-M) is an internationally renowned institute for climate research. Its mission is to understand Earth's changing climate.


The MPI-M comprises three departments and, together with the Opens external link in current windowUniversity of Hamburg, an international PhD program:

The Atmosphere in the Earth System

The Land in the Earth System
The Ocean in the Earth System


In addition the institute hosts independent research groups focused on the following topics:


Scientists at the MPI-M investigate what determines the sensitivity of the Earth system to perturbations such as the changing composition of its atmosphere, and work toward establishing the sources and limits of predictability within the Earth system. MPI-M develops and analyses sophisticated models of the Earth system, which simulate the processes within atmosphere, land and ocean. Such models have developed into important tools for understanding the behaviour of our climate, and they form the basis for international assessments of climate change. Targeted in-situ measurements and satellite observations complement the model simulations.


Together with several other non-university research institutions the MPI-M and the University of Hamburg constitute Opens external link in current windowCliSAP, a centre of excellence for climate research and education in Hamburg, Germany.

Focus on

New study: Cooling by aerosols weaker and less uncertain

The new study "Rethinking the lower bound on aerosol forcing" in the Journal of Climate, written by Prof. Bjorn Stevens, director at the Max Planck Institute for Meteorology (MPI-M) and head of the department "The Atmosphere in the Earth System", presents a number of arguments as to why the cooling effect of aerosols is neither as strong nor as uncertain as has previously been thought.

A perturbation to the composition of Earth's atmosphere can be quantified through a perturbation of the radiative balance at the top of the atmosphere ("radiative forcing"). Radiative forcing is a motive force for climate change; for small perturbations Earth's global mean surface temperature is expected to change proportionally with this forcing. Aerosols in the atmosphere contribute to the radiative forcing; if there are more aerosols, they typically reflect more of the incoming solar radiation back to space and thus cool the surface. When, in the early 1990s, this effect first began to be considered quantitatively, it was estimated to have been -2.3 W/m2, which would have largely offset the warming effect of greenhouse gases at that time. Over time, research has pointed toward a lower magnitude of the aerosol forcing, but has had a difficult time ruling out the possibility of a very strong cooling effect from aerosols. Read more