A chilling prophecy comes to us from James Hansen, 68 years of which almost 30 spent at NASA's Goddard Institute for Space Studies: he almost never makes an observation wrong. In 1981 he wrote that the following decade would mark peak heat and the prediction came true.
In the early nineties he said that the first decade of the new century would break the previous record and once again the facts proved him right. Let's hope you're wrong now because the scenario he draws is a nightmare: an increase in sea level of 7 meters at the end of the century.
Possible? “Not just possible”, Hansen replies, “but very likely if we behave as humanity did in a film that has just been released, The age of stupid: we live in a moment in which we can choose: take the path that allows us to slow down global warming or take the path that drags us towards a world similar to the Pleistocene, when sea levels were 25 meters higher."
The IPCC, the UN scientists' task force, reduces the estimates, speaking of a growth of the oceans by about half a meter. Hanson slows down the relief given the data in hand: “The UN predicts lower growth because it takes into consideration only a few factors, such as the thermal expansion of water due to the increase in temperature. The crucial element, deglaciation, is not counted for a very simple reason: the model cannot calculate it reliably."The scientist bases his prediction on the analysis of what really happened in the past when the concentration of carbon dioxide in the atmosphere made a sharp jump. By comparing today's data with paleo-climatic data, we can measure the extent of the risk: if the use of fossil fuels is not cut, the glaciers of the Antarctic peninsula, which are currently losing 200 cubic kilometers per year, will melt within a century. This will produce a 6-7 meter rise in sea level to which collapsing glaciers in areas such as Greenland will have to be added.The alternative?Immediately radically reduce the use of fossil fuels, starting with coal. It is the only possible one, because even two degrees more in a century is too much. “So far the inertia of the system has helped us,” concludes Hanson, “because for example the mass of water in the oceans has slowed down global warming. But inertia is not an ally in the long term: as soon as the trend is reversed, the oceans will begin to accelerate the process." By immediately eliminating the use of coal, the journey towards securing the planet could begin within twenty years.
