Climate Engineering

Targeted interventions in the climate system are the subject of intense debate

While there is still hope that risks from climate change can be limited by cutting greenhouse gas emissions, there is also a perception that ‘time is running out’. This perception of a looming watershed has given rise to calls for research on intentional, large-scale interventions into the climate system, referred to as either ‘climate engineering’ or ‘geoengineering’. Both terms describe a diverse and largely hypothetical array of methods for manipulating the global climate in order to moderate or forestall some of the numerous impacts of climate change.

So far, the success of efforts to reduce the emission of greenhouse gases has been limited. Moreover, international climate negotiations and the transformation of energy infrastructures towards sustainability remain slow-paced. Should current emission patterns continue, this will likely lead to substantial global warming, sea level rise, ocean acidification, and changes in the frequency, intensity and locations of weather extremes. Many societies will struggle to adapt to these changes. Targeted interventions in the climate system have the potential to allow a degree of control over global average temperatures.

Promises and risks of climate engineering

There are various approaches to intentionally intervening into the climate. These are commonly grouped according to whether they attempt to actively remove carbon dioxide and other greenhouse gases from the atmosphere or whether they attempt to reflect incoming sunlight away from Earth and back into space. Options for removing greenhouse gases from the atmosphere include large-scale afforestation, the enhancement of weathering processes, or the direct capture of greenhouse gases from ambient air for subsequent storage. Options for reflecting sunlight back into space include the injection of reflective aerosol particles into the stratosphere or the brightening of marine clouds through the injection of cloud condensation nuclei, such as sea salt.

However, current knowledge suggests that any potential benefits of such interventions would be accompanied by significant risks and uncertainties. Climate engineering techniques are therefore the subject of intense debate and controversy within academia and society at large, which goes beyond the limited consideration of whether we are technologically capable of controlling global average temperatures. Rather, climate engineering emerges from a complex set of interactions between societal and technological developments that needs to be taken into account. These interactions shape the emergence of climate engineering approaches onto political agendas. Understanding this reflexive relationship is crucial to producing comprehensive, relevant knowledge to support decision-making about climate engineering.

IASS research on climate engineering

Our interdisciplinary team brings together physicists and chemists, international lawyers, political scientists as well as representatives from the fields of geography, philosophy and psychology.

We are especially interested in the governance of climate engineering techniques, including field experimentation on such techniques. We also work on the use of computer models to understand the impacts of sunlight-reflection techniques, and on the societal perception and deeper ethical implications of the full range of climate engineering techniques. A key aspect of our work is the transdisciplinary interaction with stakeholders from civil society and the policy-making community, to improve the accuracy, relevance and impact of our work. 

Photo front page: (c) istock


Prof. Dr Mark G. Lawrence


Managing Scientific Director

Dr Thomas Bruhn


Project Scientist

Sean Low


Research Fellow

Dr Stefan Schäfer


Program Leader

Katharina Beyerl


Project Scientist

IASS Fact Sheet 1/2013: Climate Engineering

With greenhouse gas emissions continuing to escalate, recent years have seen
a growing discussion on climate engineering (CE) – an array of proposed methods
for manipulating the global climate in order to moderate or forestall the effects
of climate change. Research has expanded rapidly and while it has become clear
that CE cannot serve as a direct substitute for emission reductions, the role of
specific CE methods as responses to climate change within a portfolio of measures
is being debated. 
concise overview by Sean Low, Stefan Schäfer and Achim Maas 


Conference film

From 18 to 21 August, more than 350 participants from 40 countries gathered in Berlin for the Climate Engineering Conference 2014. They discussed a multitude of questions associated with technical interventions in the climate system.

Argument Browser

Interactive graphic

The argument browser enables you to explore complex debates by selecting arguments and discovering their direct and indirect attack and support relations with other arguments and theses.


Field Tests of Solar Climate Engineering


Letter in the journal "Nature Climate Change" by IASS scientists Stefan Schäfer, Peter J. Irvine, Anna-Maria Hubert, David Reichwein, Sean Low, Harald Stelzer, Achim Maas and Mark G. Lawrence

Geoengineering our Climate?


A Working Paper Series on the Ethics, Politics and Governance of Climate Engineering


"Rethinking Climate Engineering Categorization"


Article in the journal "WIREs Climate Change" by IASS scientists Mark G. Lawrence, Achim Maas et al.

Earth's Future in the Anthropocene


Article in the journal "Earth's Future" about Climate Engineering in the context of the wider setting of societal development in the Anthropocene by Stefan Schäfer, Harald Stelzer, Achim Maas and Mark G. Lawrence