Beware of the "Temperature Debt"
Artificial cooling of the atmosphere with aerosols carries a long-term risk
The Paris climate agreement obliges the international community to limit global warming to two degrees. However, man-made greenhouse gas emissions continue to increase instead of decreasing. Is climate engineering a solution to slow global warming? In the current issue of the journal Nature, Professor Andreas Oschlies from GEOMAR Helmholtz Centre for Ocean Research Kiel warns of an underestimated long-term risk of solar radiation management, one of the proposed climate engineering measures.
When the Pinatubo volcano erupted in the Philippines in 1991, it blew huge amounts of dust and gases into the atmosphere. Therefore, solar radiation was partly reflected instead of warming the earth's surface. Global average temperatures in the lower atmosphere temporarily dropped by half a degree. So why not copy the volcano by deploying large quantities of aerosols into the atmosphere in order to slow down the current global warming?
This idea is already being discussed internationally and first tests are under way. However, in today's issue of the journal Nature, the biogeochemist Prof. Dr. Andreas Oschlies from the GEOMAR Helmholtz Centre for Ocean Research Kiel warns of an often disregarded side effect of so-called Solar Radiation Management (SRM). "Once you start SRM on a large scale, you cannot stop it without significant risks. This has been shown by many computer simulations of the Earth system," he emphasizes.
Reference:
Oschlies, A. (2018): Solar engineering must take temperature debt into account. Nature 554, 423 (2018), https://www.nature.com/articles/d41586-018-02203-x