5.14 What about geoengineering? Won't that help us to control the climate?

This is an area where the social context of science is important, linking science, technology and ethics.

Geoengineering has been persistently talked about for a number of years now. As politicians avoid the challenge of reducing emissions and the impacts of climate change become more apparent, these solutions are being given increasingly serious attention – mainly in the belief that we can't afford to dismiss any potential solution.

Geoengineering solutions aim to cool a warming planet. Solutions can be divided broadly into two groups. One attempts to deal with short-wavelength radiation by reducing the amount of solar radiation entering the Earth's climate system. Examples include attempts to increase the Earth's albedo by cloud whitening or placing arrays of mirrors in space. The other group deals with long-wavelength radiation by attempting to reduce the amount of CO2 in the atmosphere. Examples include ‘biochar’ (turning biomass into charcoal and accelerating the uptake of carbon by soils) and fertilising plankton blooms in the oceans.

If they work (a big ‘if’), short-wavelength solutions are likely to act more quickly (almost instantaneous for some solutions) than long-wavelength solutions (tens of hundreds of years or more). Short-wavelength solutions won't deal with ocean acidification; long-wavelength solutions tend to involve very large-scale perturbations in regional or global ecosystems, which may involve adverse side effects.

Given the very substantial regional variations in climate in both space and time, geoengineering solutions inevitably raise fundamental ethical questions about who controls the climate and in whose interests is that control operated?

  • Robert Socolow (Princeton University) has some thought-provoking Powerpoint slides on ‘Prospicience and geoengineering: what if we can dial our future?’

  • RealClimate has a collection of briefings and discussion on geoengineering.

Activity 1

Think through these questions to explore the relationships between science, climate change and geoengineering solutions.

  • What ethical considerations should be taken into account in deploying geoengineering solutions?

  • Is it even sensible to think about ‘controlling’ a system as open and complex (and ever changing) as global climate?

  • What would be the ‘desired’ global average temperature?

  • How would we keep it there?

  • Who would make the decisions, over what spatial and time scales and in whose interests?

  • What do we really mean when we say we want to make the world a ‘better’ place?

5.13 Do we have any control over climate impacts in the future?

6 What are the regional effects of climate change on different parts of the world?