Memo to Paris negotiators: start talking about geoengineering
The Paris climate meeting is at risk of getting mired in the same fruitless debate that dogged the Copenhagen summit, only now it is even more fatuous.
Limiting greenhouse gas emissions to levels that are likely to result in less than either 1.5 or 2 degrees C of warming is now beyond our grasp. The full warming potential of greenhouse gases takes decades to be realised, and there is already enough gas in the air to take Earth’s average surface temperature to 1.5 degrees by mid-century. At the time of the Copenhagen meeting in 2009 it was remotely possible to cut emissions fast enough to avoid 2 degrees, but we’ve been following a worst-case scenario trajectory for emissions ever since, and it is widely recognised in the scientific community as impossible to cut emissions fast enough to achieve that now.
A world 1.5 degrees warmer is one without a Great Barrier Reef. It’s a world of rapidly rising seas, much more extreme weather, and rapidly declining biodiversity. A world of 2 degrees is one at risk of tipping into the abyss of climate chaos - a world in which our global civilisation is at increasing risk. This results from 21 years of failure to agree on climate action: it is hard to look such bad news in the eye and continue to strive for a better climatic future, which is perhaps why the negotiators continue to discuss ways of achieving the impossible.
"A world 1.5 degrees warmer is one without a Great Barrier Reef."
There are measures we could take, however, that would allow us to stay within 2 degrees, but they involves actions not being discussed in Paris. Some of these measures are, in my view, highly undesirable, while others are essential to our future.
If the first way is emissions reductions, the second way is geoengineering. The temptation to use catastrophic geoengineering methods such as injecting sulphur into the stratosphere is increasing. Sadly we are not negotiating a treaty to ban such extreme measures at Paris. Nor are we discussing the ‘third way’, which involves drawing carbon dioxide out of the atmosphere at a scale that makes a difference to our climate.
Third-way pathways are extraordinarily varied, from seaweed farming to the manufacture of carbon-negative cements and the production of carbon fibres and plastics from atmospheric CO2. Today, all such methods and technologies are nascent, and if we hope to have them operating at the gigatonne scale by mid-century we need to start investing in them now.
If we are serious about limiting temperatures to 2 degrees, they need to be high on the agenda of the first post-Paris meeting to review actions, hopefully in 2020.
Melbourne Sustainable Society Institute
University of Melbourne
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