If anyone has ever wondered what, in concrete terms, the effort required of the world to save us from climate catastrophe actually looks like, the answer has come from the coronavirus crisis. According to calculations by the British organisation Carbon Brief, the crisis will allow the planet to achieve the largest annual fall in CO2 emissions in history — greater than the one recorded in 1945, the final year of the Second World War, and five times larger than that of 2009, which was caused at the time by the global financial crisis.

Emissions will fall by more than 2 billion tonnes of CO2

This year, greenhouse gas emissions are expected to drop by around 5.5 per cent compared to 2019. This means we will avoid releasing between 2 and 2.5 billion tonnes of CO2 equivalent into the atmosphere. Is it possible that even this will not be enough to meet the climate targets set by the international community? Apparently so.

According to the Emission Gap report by the United Nations Environment Programme (Unep), if we are to limit the rise in average global temperature to a maximum of 1.5 degrees Celsius by the end of the century relative to pre-industrial levels, an annual reduction in emissions of 7.6% will be required — and this must be achieved every year from now until 2030.

A sharp drop in CO2 also forecast in Europe due to the coronavirus

In other words, to avoid climate catastrophe, we will need the equivalent effect, in terms of emissions reductions, of a coronavirus crisis every nine months. The Carbon Brief figures are, moreover, consistent with those of the Paris-based consultancy Sia Partners, which, focusing solely on Europe, similarly projected an annual contraction in CO2 emissions of 5 per cent.

The reality is that the average global temperature curve will not begin to reverse "until net emissions are brought to zero", the British organisation points out. The coronavirus crisis can therefore represent either a brief interlude or the beginning of an epoch-making change. In the first case, we will have saved ourselves from the epidemic but will not have secured a future for the planet.