Bjorn B. Stevens To What Extent Do Aerosol Particles in the Atmosphere Mask the Effects of Greenhouse Gases?

Bjorn B. Stevens is Director of the Department for the Atmosphere in the Earth System, at Max Planck Institute for Meteorology and teaches at the University of Hamburg. Previously, Stevens was a Professor of Dynamic Meteorology at the University of California, Los Angeles (USA). Stevens has made major contributions to the research on atmospheric convection in the climate system. He was awarded the Clarence Leroy Meisinger Award of the American Meteorological Society, and is an associate fellow at various institutions, including the Alexander von Humboldt Society.

Area of Research

Meteorology, Atmospheric Science

Sandrine Bony, Bjorn Stevens, Dargan M.W. Frierson, Christian Jakob, Masa Kageyama, Robert Pincus, Theodore G. Shepherd, Steven C. Sherwood, A. Pier Siebesma, Adam H. Sobel, Masahiro Watanabe and Mark J. Webb. "Clouds, Circulation and Climate Sensitivity." Nature Geoscience 8 (2015): 261-268.  
Bjorn Stevens. "Water in the Atmosphere." Physics Today 66 (2013): 29-34.  
Bjorn Stevens and Stephen E. Schwartz. "Observing and Modeling Earth’s Energy Flows." Surveys in Geophysics 33 (2012): 779-816.  
Thorsten Mauritsen and Bjorn Stevens. "Missing Iris Effect as a Possible Cause of Muted Hydrological Change and High Climate Sensitivity in Models." Nature Geoscience 8 (2015): 346-351.  
Bjorn Stevens, Sandrine Bony, Hélène Brogniez, Laureline Hentgen, Cathy Hohenegger, Christoph Kiemle, Tristan S. L'Ecuyer, Ann Kristin Naumann, Hauke Schulz and Pier A. Siebesma. "Sugar, Gravel, Fish, and Flowers: Mesoscale Cloud Patterns in the Tradewinds." Quarterly Journal of the Royal Meteorological Society (2019). doi:10.1002/qj.3662.  
Sandrine Bony and Bjorn Stevens. "Measuring Area-Averaged Vertical Motions with Dropsondes." Journal of the Atmospheric Sciences 76 (2019): 767–783. doi:10.1175/JAS-D-18-0141.1.  

since 2009


University of Hamburg (Universität Hamburg)

since 2008


Max Planck Society (more details)

Max Planck Institute for Meteorology



University of California

Department of Atmospheric and Oceanic Sciences


Visiting Scientist

Max Planck Society (more details)

Max Planck Institute for Meteorology


Post-Doctoral Fellow

National Center for Atmospheric Research, USA


PhD in Atmospheric Science

Colorado State University


Master in Electrical Engineering

Iowa State University


- The Clarence Leroy Meisinger Award of the American Meteorological Society (2002)


- Alexander von Humboldt Foundation (1998-1999)

© Maximilian Dörrbecker

Max Planck Society

Hamburg, Germany

"The Max Planck Society is Germany's most successful research organization. Since its establishment in 1948, no fewer than 18 Nobel laureates have emerged from the ranks of its scientists, putting it on a par with the best and most prestigious research institutions worldwide. The more than 15,000 publications each year in internationally renowned scientific journals are proof of the outstanding research work conducted at Max Planck Institutes – and many of those articles are among the most-cited publications in the relevant field." (Source)


Max Planck Institute for Meteorology

"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. 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. For that purpose MPI-M develops and analyses sophisticated models of the Earth system. Targeted in-situ measurements and satellite observations complement the model simulations." (Source)


Since the rise of industrialization more and more greenhouse gases are being emitted into the atmosphere and as a result the earth’s climate is warming. It is known that part of the temperature rise is balanced by aerosol particles in the atmosphere – partly also emitted by human activity. The extent of that balancing however is unknown. As BJORN B. STEVENS explains in this video, the researchers used a new approach to estimate how strong this effect actually is: they used a top down perspective and asked if the assumptions made in earlier studies are consistent with current observations. Their findings show that the cooling effect of aerosol particles is not as large as previously calculated. Most significantly, this means that we do not have to fear an increase of global warming due to cleaner air.

Rethinking the Lower Bound on Aerosol Radiative Forcing

  • Bjorn Stevens
  • Journal of Climate
  • Published in 2015
Bjorn Stevens. "Rethinking the Lower Bound on Aerosol Radiative Forcing." Journal of Climate 28 (2015): 4794-4819.