As a consequence, I expect to see a major diversion of investment from fossil fuels to clean energy before long. Let me explain that uplifting prognosis using an account of recent history.

On 18 April, Carbon Tracker, a small group of financial analysts that I chair, published its second report. In our first report in 2011, we had calculated the amount of “unburnable carbon” in coal, oil and gas reserves if governments meet their commitments to keep the rise in global temperatures below the danger threshold of 2°C; the figure we reached for this “stranded” carbon was 80%.