A data and a projection. The fact is that the temperature of the oceans is now the same as 125,000 years ago, at the time of the last interglacial era; the projection is that, as then, the water level will increase of 6-9 meters, which means submerging all coastal cities on the planet, New York included. Catastrophism? No, oceanographic observations of a research conducted by Jeremy Hoffman of the Oregon State University and published in the prestigious journal Science.
Twenty cm in 10 years
In the last hundred years the oceans raised of 20 centimetres; this trend might not only continue but also become faster. We are talking about centuries, not decades and therefore man has the possibility to put in action a series of harm reduction strategies, but now the process is initiated.
The human factor
The research highlights for the proponents of the thesis according to which everything is in the course of the natural evolution of the Earth, that this comparison between yesterday and today does not imply that climate change is a natural phenomenon as the trend of temperature in the interglacial period, rather the contrary. By comparing different rocky sediments and the fossil plankton, was in fact noticed a change in temperature identical to the one occurred from 1870 to 2014, but which in the past has happened in more than four thousand years. A sharp acceleration, whose only cause would be the intervention of man.
The process, as we said, is now triggered. Even if today we were able to stop the global warming, it would be too little to avoid large parts of the globe from ending up definitively underwater; and we are not even doing it: from COP21 we strive not to increase the global temperatures of 1.5 – 2°C, too little. In addition, there is the shadow of the new American policies with respect to the environment, which could contribute to aggravate this situation.
Nobody knows what will happen, but certainly it will not be a bed of roses. The raising of the water could change the directions of oceanic currents, in particular the current of the Gulf, and Europe would thus risk being condemned to a glacial era, while the rest of the world would heat up. Even the behaviour of the South and North Pole is difficult to understand; if the Arctic melts at twice the rate of the ice of the rest of the world, the Antarctic is cooling, losing gigantic pieces. One of these, still attached with a superfine isthmus, is almost as big as the Umbria Region.
The research of this year should be seen in correlation with another, dated 2015, carried out by Nasa, according to which from the beginning of the XX century the level of the oceans raised approximately of 20 cm and of more than 8 cm over the past 20 years. What worries more Nasa and other space agencies is what will happen to the ancient ice-caps covering the Greenland and the Antarctic, which seem increasingly unstable.
The fate of the glaciers
Tom Wagner, of the cryosphere program of Nasa, said he was worried: “From the paleoclimatic data we have seen that, if the ice-caps will rapidly break in pieces, an increase in the level of the oceans of ten feet in a century or two is possible. We are observing the evidence that the ice-caps are moving, but we need to better understand before being able to say that we are in a new era of rapid ice melting”.
In 2002 Nasa and the German space agency launched the Gravity Recovery and Climate Experiment, the twin satellites Grace which measure the movements of the mass, then the gravity, of the Earth every 30 days. If the land masses are stable, the water masses are very dynamic and Grace records these movements throughout the planet. The other new system is Argo, an international network of more than 3,000 ocean sensors floating in the open sea. Man is therefore able to monitor, evaluate, and to some extent predict. We are not in front of an impending catastrophe, but we cannot pretend nothing is happening. We are already behind schedule, but humanity does not seem to want to realize it.