Can the world reconcile its hunger for energy with the need to fight climate change? The answer depends on whether it can find greener, cheaper, more efficient ways to produce and deliver that energy. But that in turn depends on the level of research and development spending, and overall investment, in this area — and the figures do not look promising.

Take the Mission Innovation initiative announced by then US president Barack Obama at the 2015 Paris climate summit — the gathering at which world leaders agreed to limit global warming to well below 2°C above pre-industrial levels.

MI’s 20 participant governments pledged to double their clean energy R&D investment in the five years to 2020. But that didn’t happen. Instead, there was a cumulative shortfall over the five-year period of more than $50bn, based on estimates from the Information Technology and Innovation Foundation, a US public policy think-tank.