Talking about geo-engineering may prevent us needing it

Geo-engineering should be a last resort; there are better steps we can take first.

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.