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The Institution’s latest report: Geo-Engineering – Giving us time to act? argues that geo-engineering could be another potential component in our approach to climate change that could provide the world with extra time to decarbonise the global economy.

Approaches to climate change: an overview

Many people believe that we are fast approaching a critical point in dealing with climate change.  Our planet is continuing to get hotter due to the release into the atmosphere of greenhouse gases, most worryingly carbon dioxide (CO2), due to human activity.

The consensus is that we cannot allow global average temperature to rise by 2oC above pre-industrial levels.  If we do - and many predict this will happen within the next few decades - dramatic changes to our climate may occur which could jeopardise modern civilisation.

What can be done to prevent this rise?  For many years, governments have primarily focused on climate change mitigation: reducing the amount of CO2 each nation emits into the atmosphere.  More recently, climate change adaptation has been embraced: an approach which sets out to ensure that critical assets, such as power generation, transport links. water supplies and the urban environment, are redesigned and rebuilt to protect against future changes in climate.

A third, less explored approach, is geo-engineering: where technology is used to remove CO2 from the atmosphere, or where the planet is cooled by reflecting solar radiation back into space.  Geo-engineering is not an encompassing solution to global warming; it is no 'silver bullet', but it could be another potential component in our approach to climate change that could provide the world with extra time to decarbonise the global economy.

Geo-engineering options

The Institution of Mechanical Engineers has undertaken an initial assessment of a range of potential geo-engineering options available under its ‘Cooling the Planet’ programme.  Of the many options reviewed, the three most promising have been outlined in this report.

1. Artificial trees

Research is being undertaken into building machines which, like trees, can remove CO2 from the atmosphere.  This occurs when air passes through the device (the tree) and CO2 sticks to a sorbent material (the leaves).  The CO2 is then removed and buried underground in the same way as conventional carbon capture and storage (CCS).

2.Algae-coated buildings

Algae naturally absorbs CO2 through photosynthesis.  Strips of algae can be fitted to the outside of buildings and then periodically harvested for use as biofuel in conjunction with a carbon sequestration solution.

3. Reflective buildings

Reducing the amount of solar radiation absorbed by the earth’s climate system has the potential to cool the planet. This can simply be achieved by making surfaces more reflective and thus lowering the heating effect the sun’s rays have on us.  Although this option may not be as effective as the other two proposals, it does have the additional benefit of reducing temperatures in urban heat islands.

Roadmap for our future

It is important that these geo-engineering options are not seen as alternatives to climate change mitigation.  To this end, the Institution proposes a climate change roadmap over the next 75 to 100 years, in which geo-engineering is an integrated supporting element in global climate mitigation and adaptation plans.

Plan B or a fully integrated component?

Despite its potential, the UK Government considers geo-engineering as a low priority: a Plan B.  However, it could be geo-engineering that provides the global community with those extra years to introduce effective mitigation and adaptation strategies and, in the long term, remove some of the existing CO2 from the atmosphere.  As such, geo-engineering needs to become a fully integrated part of a comprehensive three-part approach embracing Mitigation, Adaptation and Geo-engineering: a 'MAG approach' to climate change policy.

Research and Development

For geo-engineering to be considered, more research into its potential to reduce global warming needs to be undertaken.  Furthermore, a realistic cost analysis and timescale of planetary wide implementation needs to be worked through.


In response to these challenges, the Institution of Mechanical Engineers has developed the following recommendations for Government and other stakeholders:

  1. Support geo-engineering research
  2. Use the resources we already have as a world leader in engineering and climate modelling
  3. Pilot promising schemes
  4. Adopt a realistic roadmap for decarbonisation of the global economy integrating geo-engineering
  5. Maximise the commercial opportunities for UK plc

Read the full report

For further information about environment policy recommendations.

For further information about the Institution’s environment theme activity.

Read the press release about Geo-Engineering.

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