So far, the estimated increase of the global temperature is 1°C average above the preindustrial period. At this rate of greenhouse gasses emissions, the temperatures could approximately rise to 2.5°C-4.4°C by the end of the century (2100). Even worse: there are countries like China, Russia and Canada which rates could lead the temperatures to reach 5°C. Scientists are then interested in understanding what would happen to our planet in case the route will continue to be the wrong one. In the HELIX (High-Ended Climate Impact and Extremes) project, climatologists examined the physical consequences for the planet depending on the different temperature rise scenarios.
What worries the most is the increasing frequency and intensity of the extreme meteorological events. Particularly, the stress provoked on the human life by the rise of heat waves, frequently accompanied by high humidity. With a 2°C increase, the areas subjected to heat waves would rapidly expand around the globe and with a 4°C increase there would be lead to dramatic consequences in the Tropics, mostly in Africa, South America and Southeast Asia.
Regarding precipitations, we will observe quite variable behaviors in the future with some areas that will be characterized by the increased frequency of drought, others by intense rain and other areas which will be subject to both phenomenon. The percentage of people damaged by floods will increase from the current 54 million to 97 million, in case of 2°C temperature rise, and 211 million, in case of 4°C temperature rise.
Another important issue will be the expected rising level of the sea, which could become extremely serious in case of collapse of the Artic glacial platform. What draw more attention are the Southeast Asian areas, particularly Bangladesh, which are densely populated and already in high vulnerability and exposition conditions. In fact, here is where rising sea level and presence of intense storms and hurricanes are combined.
Among the elements analyzed by the researchers, it has been particularly underlined the increasing risks for the world’s population related to food safety, which is measured in terms of availability, access, stability, and possibility of use of the food. Again, Africa and Southeast Asia suffer the higher risks. Already with a 2°C increase, several areas of the planet will reach levels of vulnerability with no precedent.
There’s a disturbing aspect which is faced by John Schellnhuber: the processes we observe as a consequence of climate change are not linear and they could reach the so-called tipping points, namely points of no return. In the future, the achievement of the different rising temperatures thresholds, 1.5°C, 2°C, till 4°C, would prompt progressive irreversible physical processes.Likely for some of them is already too late, such as for the fusion process of the Arctic Glacial Sea, Greenland glaciers and also for the continental mountain ones like the Alps.
There are also concerns about the modifications in progress in the global atmospheric circulation. The abnormal increase of the temperature in the Arctic affects, for instance, in the behavior of the so-called jet stream which is as a matter of act responsible for the weather in Europe. Anomalous drought, such as the ones happened in spring and summer 2018 in Northern Europe, and the intense rains in Italy at the end of October, are consequences ascribed to the modifications of the jet stream.
The situation is therefore extremely critical. Of course, it’s still possible to intervene. In fact, there are no physical impediment to the reduction of the greenhouse gasses emissions and the available technology would be helpful yet. However, we need a political will which has find all the countries united in one huge effort of cooperation and responsibility. That’s what we expect here in Katowice.
Why, instead, are the negotiations going very slowly? Why is there resistance? Probably the social and economic system we live in displays all its own limits. What if indeed is the system to be wrong? That’s the question that Schellnhuber asks himself and answers recalling to the necessity to cause a social change which could not be produced by the UN Conference on Climate Change.
It then up to us, civil society, to propose a "new narrative of the world" and to cause a "big bang toward a social change" which would guarantee better life conditions to mankind in this planet.
Tommaso Orlandi (Translation)
Tommaso Orlandi (Translation)