It is well known that the Paris Agreement aims to keep climate change – perhaps the greatest current challenge to global sustainability – to within 2 °C of warming, and to strive for 1.5 °C. Many people point toward the scenarios used by the Intergovernmental Panel on Climate Change (IPCC) and conclude that this is feasible if only our leaders had the political will to do what’s necessary. However, it is less widely known that these scenarios assume the use of technologies to remove carbon dioxide from the atmosphere at very large scales. As global emissions have not lessened in the seven years since the scenarios’ development, more recent projections to stay within 2 °C and especially 1.5 °C rely upon both more aggressive emissions cuts and larger scales of ‘negative emission technologies’ (NETs). Yet not only are NETs’ actual development and scalability still uncertain, the technologies would present social and environmental risks of their own.

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