There is no doubt that our climate is changing. Most of us would agree that it is caused by humans. But what if we have passed the point of no return? James Manning reports.

In climate science, there exists what is known as the ‘tipping point’ – the point at which what has been done to our environment cannot be reversed. Once we have reached this tipping point, the effects of climate change will be permanent, even if we stop burning fossil fuels and switch to completely green energy.

This is where plan B comes in.

Geoengineering tackles the problem from a different angle; like an assault on climate change rather than a defence. It is not a new science, but it is definitely controversial.

It is a more aggressive form of climate change mitigation, broadly defined as the human manipulation of the natural environment on a global scale in order to directly alter the climate and reverse the effects of climate change.

There are two main types of geoengineering: carbon dioxide removal, which aims to leach excess carbon from the atmosphere; and solar radiation management, which aims to cool the earth by deflecting sunlight. Each has their fair share of merits and weaknesses.

Overview

Prevention is the best cure – the scientific community agrees cutting carbon emissions should be the first priority in the fight against climate change. However, like most of the issues facing society today, it’s all caught up in politics.

The global community has been holding conferences and signing treaties for over 20 years. Margaret Thatcher first gave a speech in 1988 outlining the scientific evidence for climate change.

“Even though this kind of action may cost a lot, I believe it to be money well and necessarily spent because the health of the economy and the health of our environment are totally dependent upon each other,” she said.

And yet here we are in 2010 and little has changed. New technologies abound, real action (ironically the campaign slogan of the do-nothing Coalition) is slow on the uptake. Fossil fuel emissions are still rising from all of the world’s major polluters.

Reducing carbon emissions at this stage may simply not be enough to rectify the consequences of climate change. The severe lack of preventative action may mean that radical theories such as geoengineering are our only remaining options.

Dr Ramsis Salama, a climate and hydrological scientist, is an advocate of geoengineering. “We need to change all our systems – we need to know how to live with climate change. The way we live, the way we use resources like water is all wrong,” he said.

“Are we going to go at the same pace at which we are going now? No – nobody can guarantee that … something might happen, something else that might make the rate of climate change explode,” said Dr Salama.

The Royal Society, a preeminent scientific research society based in London, agrees. Their report Geoengineering the climate: science governance and uncertainty released late last year, states:

“Unless future efforts to reduce greenhouse gas emissions are much more successful than they have been so far, additional action in the form of geoengineering will be necessary if we are to cool the planet.”

“Some of these proposals may seem fantastical, and may prove to be so,” said Professor John Shepherd, chair of the geoengineering studies being undertaken at the Royal Society.

It has steadily gained popularity as scientists have become aware of the fact that reaching the tipping point for our environment is not matter of ‘if’, but ‘when. Indeed, we may have already passed it.

As a result, it has risen to the political agenda in some countries, such as Switzerland and the United Kingdom. Closer to home, the Victorian state government recently invested $250,000 in a ‘climate intervention technologies’ conference held in California in March, hosted by the US Climate Response Fund.

The conference, which included scientists from the United States, Europe and a former CSIRO scientist, discussed international guidelines for the application of geoengineering, risk assessment, social considerations and funding opportunities.

“This conference has been important step in determining the special considerations and obligations associated with research on climate intervention and remediation,” said Dr Michael McCracken of the Climate Response Fund at the conference.

Perhaps most important was the discussion of social and legal perspectives on geoengineering, rather than focussing purely on the science and ecological risks involved.

The general consensus reached was that until it is absolutely necessary, and further testing has been done, geoengineering should not be utilised, but that research should continue to be conducted.

Apart from this isolated instance by the Victorian Government, Australia and the CSIRO do not currently research or invest in any form of geoengineering, and declined to comment on an area of research in which they are not involved.

In the UK, however, an inquiry into geoengineering was held before the House of Commons earlier this year. British parliament concluded that regulation of geoengineering was crucial in order to monitor current research and prepare for future applications.

“If we start work now it will provide the opportunity to fully explore the technological, environmental, political and regulatory issues,” said a Government report on the inquiry.

The report states that regulation should be international due to the global nature of the technologies involved, and that individual regulatory frameworks must be developed for different technologies because they are vastly different in nature. The inquiry also called for international disclosure of the findings of geoengineering research.

Carbon dioxide removal

We simply have too much carbon dioxide in our atmosphere. Carbon dioxide removal, as the name suggests, aims to rectify that. While these technologies address the core of the problem, they work slowly over a very large time scale.

The most popular form of carbon dioxide removal is ocean fertilisation, whereby the ocean is fertilised with iron, which stimulates the growth of carbon capturing plankton.

There are problems with this though – the carbon captured does not sink deep into the ocean easily, and once it does, it has a tendency to make the surrounding ocean low in oxygen. Needless to say, this can have alarming effects on marine biodiversity.

Another form of carbon dioxide removal, also known as carbon sequestering, uses mirrors and sunlight to leach carbon out of the air. This method is currently being researched in Switzerland at the Paul Scherrer Institute and Swiss Federal Institute of Technology.

Giant mirrors direct intense sunlight into laboratories, creating extreme temperatures up to 2000 degrees Celsius. When the compound calcium oxide is heated in these extreme temperatures, it leaches carbon dioxide out of the air, transforming it into calcium carbonate, or limestone powder. The powder is then further heated, at which point the calcium carbonate breaks down to calcium oxide and carbon. The calcium oxide can be reused and the carbon can be liquefied and stored.

Using this method, carbon dioxide could potentially be returned to atmospheric concentration levels not seen since before the Industrial Age.

However, this method also has its problems, such as safety issues and the cost of storing the carbon. Despite this, the Swiss Federal Institute of Technology endeavours to build a plant this year that has the ability to capture approximately one tonne of carbon dioxide every day.

Dr Salama explained why geoengineering is still in its infancy: “We have previously conducted a lot of research and geological experiments at the CSIRO on the sequestering of carbon dioxide, liquefaction of carbon dioxide and injecting it underground,” said Dr Salama.

“Research is still going on elsewhere, but to do it we have a long way to go. It is a solution, if you can find an easy way to transform carbon dioxide and inject it underground or into the oceans. It’s very good but it’s still very experimental and is only being done in very small amounts,” said Dr Salama.

Dr Salama warns that geoengineering techniques are only intended as a back-up plan: “Unless we stop the mechanism by which this is happening – humans – we can never stop the cycle.” There is a danger, after all, of creating public disillusion that geoengineering is a quick fix that enables to carry on polluting the way we have been for hundreds of years. This is definitely not the case.

Solar radiation management

Solar radiation management, on the other hand, aims to cool the planet by deflecting the sun’s rays back out to space. Unlike carbon dioxide removal, solar radiation management could act quickly to reduce the temperature of the planet in the event of a crisis.

One theory, developed by the 2006 Nobel Prize winner Professor Paul Crutzen, suggests injecting large amounts of sulphur into the atmosphere, like a volcano eruption.

Some argue that this is just fighting pollution with pollution, as there are side effects to adding copious amounts of sulphur to the atmosphere, such as the acid rain. Large amounts of sulphur also have the potential to destroy ozone particles. Moreover, sulphur does not last long in the atmosphere, and so would have to be continuously added – which does not come cheap.

With all these techniques, there is the possibility of other side effects that are not yet known, and will not be until they are tried. For example, altering the composition of the atmosphere, as suggested by the injection of sulphur, can have devastating effects on global weather patterns.

It is possible that entire seasons could shift, altering rainfall patterns and having unforseen impacts upon crops and global food supplies.

“We are going to face a lot of problems. We have to be certain about that,” warned Dr Salama.

Professor Shepherd agrees: “None of the geoengineering technologies so far suggested is a magic bullet, and all have risks and uncertainties associated with them.”

Other solar radiation methods include placing large mirrors in space to deflect the sun’s rays and the “bleaching” of clouds to increase reflectivity. However, these methods are very expensive and their side effects unknown.

Unlike carbon dioxide removal, solar radiation management does nothing to reduce the amount of carbon already in the air and its associated impacts, such as the acidification of oceans.

The Royal Society report concludes: “Geoengineering methods should only be considered as part of a wider package of options for addressing climate change … used irresponsibly or without regard for possible side effects, geoengineering could have catastrophic consequences similar to those of climate change itself.”

The Royal Society, the British Parliament and the Climate Response Fund have all recommended the establishment of ethical guidelines.

Geo-engineering the future

Many scientists now believe that one day, in the not too distant future, geoengineering may be our only option for survival.

But plan B is not without risk. Are the dangers it brings with it too great? What price do we put on the future of our planet, and indeed ourselves?