A lack of global action to combat climate change is forcing scientists to explore measures that might have been considered unethical a decade ago.
With carbon dioxide emissions tracking at the high end of predictions (and beyond) and the impacts of climate change becoming clearer by the day, scientists are moving beyond mitigation and adaption approaches. For the first time, they are seriously discussing geo-engineering – altering the planet physically or chemically to reduce the effects of climate change – as a potential emergency measure.
Over two days in late September, more than 60 scientists, engineers, social scientists and interested people gathered in Canberra for a symposium: Geoengineering the Climate? A Southern Hemisphere Perspective.
If all else fails …
Geo-engineering is in sharp contrast to mitigation – which aims to reduce greenhouse gas emissions – and adaption – which develops local and regional responses to climatic changes.
For both mitigation and adaption strategies, the ethical and governance challenges are considerable, but predictable. For example, some countries that are the highest emitters of greenhouse gases per person, such as Australia and the United States, were the slowest to sign on to global mitigation agreements, like the Kyoto Protocol.
With geo-engineering, the consequences are untested and dangerously unpredictable.
For this reason, it was made quite clear at the symposium that geo-engineering (or “climate remediation” as the attendees called it) could not replace the urgent need for substantial national and international efforts to mitigate climate change.
In exploring the consequences of geo-engineering, the symposium divided the potential strategies into two groups – those that remove carbon from the atmosphere and those that reflect sunlight back into space.
Removing carbon from the atmosphere
The first group of technologies discussed were those that could conceivably remove carbon from the atmosphere and lock it in vegetation, soils or oceans or inject it underground.
These technologies included:
- changes to land cover management – this includes looking at trees, crops and other sources of sequestration
- changing agricultural practices to increase carbon uptake in soils
- fertilising the ocean using iron or nitrogen
- direct capture of carbon through carbon capture and storage (CCS) technologies.
Some of the least risky of these options are already being used to mitigate against climate change. These include reforestation and increasing soil carbon.
The symposium found there was a sizeable difference between the perceived potential of these approaches and what is realistically achievable in the next 40 years.
For example, there are considerable difficulties in increasing the carbon content in Australian soils due to the low nitrogen content. In addition, it is difficult to measure and validate the amount of carbon actually sequestered.
Similarly, the future of CCS is far from clear. CCS technologies remain underfunded by industry and research and development is slow. At best, CCS can only be regarded as a part of the solution and has yet to demonstrate it is safe, effective, permanent and economically viable.
Increasing reflection of sunlight
The second group of technologies is focused on reducing the amount of sunlight that reaches Earth and warms the planet. This could be achieved by increasing the reflectivity of the Earth’s surface or the reflectivity of clouds and particles in the atmosphere.
Some of the technologies examined increase reflection at the surface by growing highly reflective vegetation for crops, and by using reflective paints on buildings.
Atmospheric technologies included attempts to increase cloud brightness and by injecting aerosols into the stratosphere.
As a group these solar radiation management technologies were considered to be the most risky.
The symposium found reducing sunlight has a significantly different effect than reducing greenhouse gas emissions in terms of resultant spatial effects, changes to temperature patterns over time, and effects on rainfall. Reducing sunlight leads to more cooling in the day time and in summer, whereas reducing greenhouse gases leads to more cooling at night and in winter. Hence, reducing sunlight cannot exactly offset the warming patterns due to increasing greenhouse gases.
The immediate climate responses may be local but would almost certainly have unpredictable knock-on effects for the climates of distant areas. Reflecting more sunlight in one region would cool the climate locally but, since the variations in climate are globally connected, such changes would likely affect weather and rainfall patterns all around the globe.
There may also be uncertain impacts on the ozone layer and other important areas in the stratosphere.
The ethical consequences
Many symposium attendees were concerned about the ethical issues associated with geo-engineering. This is due to the widespread and unpredictable results of some of the remediation technologies.
An early view expressed at the symposium was that any research on solar radiation (sunlight) management was simply a way of ignoring and diverting funds from the process of mitigating climate change.
Of course, climate remediation might just be necessary, if the persistent lack of global action continues and we pass the point of no return.
If the climate gets beyond that tipping point, geo-engineering might be able to minimise the effects of global climate change while the reduction of greenhouse gases takes effect.
Of course, there are many ethical concerns about this approach, including:
- the unforseen impacts of climate remediation
- the effect these untested approaches may have beyond the borders of the countries that institute geo-engineering solutions
- the burdens geo-engineering could place on future generations.
The governance consequences
The world is currently struggling with governance issues around reducing carbon emissions and has been since the 1992 Framework Convention on Climate Change. In that time, no policy or action has made a meaningful impact on the increasing rate of global carbon emissions.
Solar radiation management systems, in particular, would be very difficult to govern. While one of these technologies could be deployed unilaterally (by a nation or private entity, at a potential cost of more than $1 billion a year), the impacts will be global and could have unanticipated consequences.
Where to from here?
At the end of the two-day symposium it was clear that ethical and governance considerations are of prime importance. It was also clear that urgent, well-informed, high-level international discussions are also needed. Such discussions could help to prevent unilateral geo-engineering before the consequences are properly understood.
The research plan, Live Within Earth’s Limits: An Australian Plan to Develop a Science of the Whole Earth System, was proposed as a foundation for all future explorations of the climate remediation issue.
While the prospect of geo-engineering is a frightening one for many people – and rightly so – it’s far better that we have these discussions now before it’s too late.
And speaking of “before it’s too late”, let’s not forget that geo-engineering is only being discussed because of inaction on other fronts. Meaningful global efforts to combat climate change are more than overdue – perhaps the upcoming UN Climate Change Conference in Durban will make some progress.
Let’s just hope we can get our act together before geo-engineering becomes a necessity, not just something we’re talking about.