We are so far behind in taking action that a 2-degree rise in average global temperature is the best scenario we have. Luca Mercalli, president of the Società meteorologica italiana, tells us about it.
In the context of the climate crisis, the time for prevention has now given way to mitigation or, more precisely, to damage limitation. Because, as climatologist and science communicator Luca Mercalli states, the point of no return was already passed forty years ago. Proof of this lies in the increasingly frequent extreme weather events, humanitarian crises, species extinctions, disappearing glaciers and the continual alarming records – such as the most recent one last month: the hottest October in history.
So superlatives are beginning to sound like the new normal, and new terms and adjectives are being sought to describe ever-worsening situations and scenarios. Indeed, we are facing an uncertain and unprecedented future, one "rigged" by human hands, to the point that scientists say we are observing a world we do not know. Because while it is true that the climate has always been in constant flux, the problems began when human activity overlapped with – and in some cases outright replaced – its natural cycles, thereby ushering in an era in which humankind is more impactful than nature itself: the Anthropocene.
It is no coincidence that the Ipcc (the United Nations Intergovernmental Panel on Climate Change) has stated that we have just over ten years to take decisive action to limit global warming or the climate will spiral out of control – to what extent is unknown, but certainly with catastrophic consequences. To better understand the situation and the scenarios we are heading towards, amid climate movements denouncing inaction and government pledges that seem far from being fulfilled, we spoke with Luca Mercalli, president of the Società meteorologica italiana, during the world forum on urban forests held at the Triennale di Milano.
What are the scenarios ahead of us, in the best and worst cases?
The two scenarios outlined by the United Nations intergovernmental treaty on climate change, and in some ways endorsed by the Paris Agreement in 2015, are on one hand a worst-case scenario – that is, one with no emissions controls – in which by 2100 we could expect a rise of as much as 5 degrees in global temperature, with catastrophic consequences for humanity. Or, on the other hand, a more cautious scenario that would keep the temperature rise below 2 degrees by the end of this century but which will nonetheless bring consequences. This is because we unfortunately have to accept that the temperature increase – which is the result of forty years of delay in addressing the problem – is already a loaded gun. Nevertheless, 2 degrees is always better than 5, provided that emissions reductions are applied worldwide, and quickly.
In this sense, are trees our allies in mitigating climate change?
The role of trees and forests in mitigating climate change is significant, but we must bear in mind that it is not a solution in itself. We are already burning so many fossil fuels that trees cannot keep pace with recapturing this carbon. We can say that they play their part, but we cannot rely on them alone to solve the problem of global warming.
Even though it is a problem that affects everyone, why are we unable to adopt a global vision and approach to the climate?
The climate is the most globalised thing we have, yet it is not being treated as such – as, unfortunately, is the case with every other problem. Perhaps to date we have only globalised finance and pollution. But we have not globalised any way of tackling the climate crisis, so much so that the Paris Agreement, signed by more or less every country in 2015, has already seen the defection of Donald Trump. So rather than globalising measures, we are instead fragmenting them into the individual choices of separate governments, with some actively working against progress.
Read also: Luca Mercalli. Così cambia il clima in Italia, caldo tropicale al Nord ed estati più lunghe al Sud
Then there is a problem of climate perception. We must bear in mind that what matters are the global data. It can happen that there is a week or a month of fortunately normal conditions – snow in the Alps in mid-November is nothing out of the ordinary. Unfortunately, we do not give enough weight to all the truly exceptional data that, at a global level, tell us that temperatures have never been this high in the past 150 years – in fact, over the past millennia too, if we look at data obtained through non-numerical methods, that is, without the thermometers we have had globally for around 150 years, while there are other methods for reconstructing temperatures going back thousands of years. We know that we are now at the warmest point in the history of civilisation. If we keep looking at the fact that it was cold in Milan for a week, we have certainly not solved the problem. It is a bit like looking for excuses, for alibis to avoid taking action.
Are we still in time to act?
We are in time, but only to reduce the damage – certainly not to recover fully. By now, forty years of delay since the first organised political-level warnings, which date back to the late 1970s, weigh heavily on any possibility of repairing this damage. So at least 2 degrees is coming our way, even if we act immediately. If we do nothing, we are in for 5.