We have learned rather quickly what the graph showing the importance of "flattening the curve" means — applying social distancing against the uncontrolled spread of the Sars-Cov-2 virus, to prevent the collapse of national health services.

Without social distancing

In short, without controls the saturation point of hospitals — not only in Italy, particularly in terms of intensive care beds — would be reached within a few days, and many people would be left without treatment. The contagion curve would grow exponentially and in a short time the entire population could contract the virus, even asymptomatically.

For Italy, this would be a disaster given that the most vulnerable people — those affected by other conditions or who are elderly — make up a significant share of the total. The percentage of people over 65 in Italy is the highest in Europe: 35.7 per cent, according to Eurostat.

With social distancing

Conversely, a few weeks of "pause" inside our homes prevents the exponential surge in the contagion curve and allows hospitals to remain below the saturation point for intensive care beds, enabling doctors to treat everyone. A scenario well described by the video (above) from the Italian State Police — worth keeping in mind now that people are returning to using public transport, among other things.

This remains, for now, the best way to counter the health emergency and overcome the new coronavirus pandemic as quickly as possible — the first since we entered the Anthropocene, the so-called "human epoch".

Now let us try to overlay the tragedy, the solution and the graphs of the health emergency with the tragedy, the solution and the graphs of the climate emergency.

Whereas the first must be confronted on a timescale of days, the second must be confronted on a timescale of years. Whereas the first has as its critical threshold the saturation point of hospitals with Covid-19 patients, the second has as its ultimate limit the saturation point of the atmosphere with greenhouse gases.

That is the carbon budget. We have fewer than eight years left in which we are physically capable of reducing greenhouse gas emissions — such as carbon dioxide (CO2) — and preventing the global average temperature from exceeding the threshold of 1.5 degrees Celsius, the limit called for loudly by scientists to avoid unforeseeable consequences for our species and for the planet.

Then there is fossil distancing

The equivalent of so-called social distancing in the climate emergency is "fossil distancing". We must stop using fossil fuels such as coal, oil and gas. Like the social kind, this form of distancing must be applied immediately, because the more time passes, the harder it will be to meet the targets of the Paris Agreement. And with every passing year, CO2 emission cuts will need to be more drastic and therefore more difficult. Just as with the coronavirus: every additional day without quarantine causes the contagion curve to rise exponentially.

Like the virus, global warming too knows no borders. CO2 emitted on the other side of the world contributes to the rise in global average temperature in exactly the same way as that emitted by traffic outside our front door.

The positive side of all this is that the solutions we are learning during these pandemic "pause" days are the very same ones we should keep in mind to get out of the climate crisis: act here and now, without waiting for someone else to act in our place; stay united; be in solidarity with one another and tackle social inequalities; each do our part to live better, together — because one person's "unhealthy" lifestyle also harms the people around them, especially the most vulnerable, whether they are strangers or loved ones.

One single overarching issue

Finally, even human reactions to the solutions adopted to defeat these enemies – the stages that follow the achievement of awareness, in short – appear to have a great deal in common.

There is disagreement and debate about the usefulness of certain measures, about the pace of recovery, about the changes we will need to adopt in order to adapt our lifestyle to altered external conditions. And at a certain point these analogies, these parallels, end up touching one another and becoming one single overarching issue that humanity will have to address in an integrated way: how to achieve a form of sustainable development.

The debate between optimists and pessimists, between those who say this pandemic is an opportunity to cut CO2 emissions and those who instead believe that after the health crisis emissions will rise again faster than before, is already out of date. Because it is no longer a matter of taking sides – it is simply a matter of survival.

As Ralph Keeling – son of the great Charles David Keeling, who gave rise to the eponymous curve that tracks, month after month, year after year, the concentration of carbon dioxide in the atmosphere – states, the first "lesson is that a trauma like this can alter emissions", but the next step is "understanding how to alter emissions without a trauma like this".

Only by returning to respect the laws of nature will we be able to avoid new pandemics; only by ceasing to destroy the wildest and most remote natural habitats to make way for urbanisation, intensive agriculture and extractive activities will we be able to safeguard our species and prevent viruses unknown to us from being forced to make the now-famous "species jump" (spillover, in English) and give rise to zoonoses.

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