Volcanoes, Nuclear War and Sulphate Geoengineering: How aerosols cool the planet

Nov. 30th - Dec. 4th, Prof. Alan Robock, a renowned expert in aerosol-climate interaction from Rutgers University (US), will visit the CCSS. 

While climate scientists and policy makers worry about global warming induced by anthropogenic CO2 emissions, powerful cooling agents can impact the climate system. Volcanic eruptions can inject SO2 into the stratosphere, where it will form a sulphate aerosol veil that reflects part of the solar radiation and causes temporary global cooling. While the recent, well-studied Pinatubo eruption (1991) only caused modest cooling of about 0.5K, the LakagĂ­gar eruption in Iceland, 1783-84, may have had dramatic impacts on the global climate. 

But man-made catastrophes could have even worse impacts: Nuclear Winter. A nuclear war using 100 Hiroshima-sized bombs would inject so much smoke from the resulting fires into the stratosphere that the resulting climate change would be unprecedented in recorded human history. The impact of the nuclear war simulated here, using much less than 1% of the global nuclear arsenal, could sentence a billion people now living marginal existences to starvation. Alan Robock took part in the International Campaign to Abolish Nuclear Weapons (ICAN), which was awarded the Nobel peace price in 2017. 

On the other hand, maybe humans could use the cooling effect of stratospheric aerosol to solve the global warming problem? Mimicking the effect of volcanic eruptions, a suitable amount of SO2 could annually be injected into the stratosphere to reflect some sunlight and counteract global warming. But this so-called geoengineering is not without side effects. What are the benefits, and what are the risks involved? 


Alan Robock will give a CLUe lunchtalk on Nuclear Winter on November 30th. On Dec. 3rd, we will organise a symposium on volcano-climate interaction, and an Dec. 4th, a symposium on geoengineering will follow. All events are open to interested researchers (registration required; see websites).  


Prof. Alan Robock

Alan Robock is Distinguished Professor at the department of environmental sciences at Rutgers University (US) since 1998. Previously, he worked at the Department of Meteorology at the University Maryland (1977-1997) and was State Climatologist of Maryland (1991-1997). His research involves many aspects of climate change, using both observational analyses and climate model simulations.  Currently, he focuses on geoengineering, climatic effects of nuclear weapons, and the effects of volcanic eruptions on climate.  Alan Robock has published more than 240 peer-reviewed papers and received numerous awards, including the   Jule G. Charney Medal of the American Meteorological Society, 2015. He was participant in the International Campaign to Abolish Nuclear Weapons, which was awarded the Nobel Peace Prize in 2017.