Geoengineering: Could far-fetched plans really halt climate change?

Analysis: Proposals include painting cities white and installing giant mirrors in Earth’s orbit

Twelve years to save the world. That is all we have, according to climate scientists who warn that global warming is the existential threat of our time.

Yet still global greenhouse emissions show no sign of peaking. A recent study found there is just a 5 per cent chance of us limiting warming to less than 2C by 2100. If we continue as we are, radical solutions are needed.

Authors of the Intergovernmental Panel on Climate Change report say it could be possible to limit warming to the best-case scenario of 1.5C. However, there’s a big catch: every one of the possible outcomes involves actively modifying the atmosphere. This technology – called geoengineering – does not currently exist.