If we do not reduce our emissions of greenhouse gases (and currently we are still there more and more instead of emitting less) than by 2084 the average temperature on our planet will have risen by four degrees in comparison with the pre-industrial era. Four degrees does not seem like much, but it is a disastrous prospect. In such a scenario, the major cities along the world's coasts have already become uninhabitable, which will result in hundreds of millions of climate refugees.
The number of forest fires will increase dramatically, also in our regions, where in such a scenario the climate will be very similar to the current one in Marrakech for example. Heat waves with temperatures of 45 degrees are all the new ones.
Until those four degrees in 2084, Chinese researchers will come in the journal Advances in Atmospheric Sciences. They rely on no fewer than 39 climate models from the Coupled Model Intercomparison Project (CMIP). This research project is aimed at the development and assessment of climate models and should eventually lead to the most accurate climate simulations possible.
The research shows that most models predict that the earth is already four degrees warmer before the end of this century than in pre-industrial times (assuming that we do not reduce our emissions). On average, the models predict that the temperature rise of 4 degrees Celsius in 2084 is a fact.
Four degrees does not seem like much, but it is a disastrous prospect. In such a scenario, the major cities along the world's coasts have already become uninhabitable, which will result in hundreds of millions of climate refugees.
Climate change could bring hell on earth
It is also a scenario in which all the ice that is still trapped in glaciers or on the poles begins to melt very quickly. That will ultimately increase the sea level by more than 50 meters. And it really goes fast: count on a meter every 20 years. The number of forest fires will increase dramatically, also in our regions, where in such a scenario the climate will be very similar to the current one in Marrakech for example. Heat waves with temperatures of 45 degrees are all the new ones.
It also means that an average summer day will be as warm as a day during the worst heat waves we now know. With a four-degree warming, countries such as Spain and Italy become largely uninhabitable, which will provide a new flow of refugees towards Scandinavia and the Baltic states, for example.
It is important to realize that once climate warming has started, it will continue for centuries, whatever measures you take. It is also true that non-linear effects ensure that 4 ° C heating is not simply twice as bad as 2 degrees of warming.
At four degrees we also ended up in what is called a runaway climate scenario. The world's permafrost will pump more than 500 billion tons of CO2 into our atmosphere. That has happened in the past and it has completely changed our planet.
The lessons from 55 million years ago
There will be no more ice at the poles, rain forests have been burned down and turned into desert, the Alps will look like the Atlas Mountains now. We end up in a situation that the earth already experienced 55 million years ago, during the Eocene.
The average temperature rose to 7 ° C at higher latitudes in barely 20,000 years, one of the fastest and largest climatic changes in geological history. The climate change caused a mass extinction - the name of it, the Grande Coupure, says everything.
The most accepted explanation of how this could be done is: as a result of the gradual warming during the Late Paleocene, the temperature of the seawater rose above a certain critical value, causing gas hydrates on the ocean floor to dissolve massively, releasing large amounts of methane into the atmosphere. .
The new study of the Chinese is really very bad news, especially when you consider that politicians are currently still working on agreements that should lead to global warming to 2 and possibly even 1.5 degrees Celsius. limited.
No effective plan that actually leads to a drastic reduction of greenhouse gas emissions.
Methane is a very strong greenhouse gas (twenty times as effective as carbon dioxide) and that would suddenly have accelerated the warming of the climate. Here is another interesting fact: the gradual warming that led to this in the Late Paleocene went 30 times slower than what we are going through.
In most models for the current global warming, no account is taken of the release of gas hydrates as a reinforcing factor. But, one thing is certain: if it happens, the earth will become unviable for man.
Methane bubbles trapped in ice
The new study of the Chinese is really very bad news, especially when you consider that politicians are currently still working on agreements that should lead to global warming to 2 and possibly even 1.5 degrees Celsius. limited. Although almost all countries on earth - with the exception of the US - have decided to do so, there is actually no effective plan that actually leads to a drastic reduction of greenhouse gas emissions.
What this research shows, is how much time is required. Because within a few decades - according to some models in 2064 already - we will have passed the goal of the Paris climate agreement.
Politicians, interest groups such as the fossil fuel sector and climate negationists have used the uncertainty inherent in climate models to raise doubts about climate change or to argue against strong policy measures.
But climate models are vital tools for scientists who try to understand the impact of greenhouse gas emissions. They are built on the basis of fundamental knowledge of the physics and climate of the world.
The climate system, however, is incredibly complex, and as a result there is disagreement about how to best model the most important aspects of it. An additional challenge is that the climate changes faster than the models improve, because events take place in the real world that the models did not predict. This is how Artic sea ice melts faster than the models can explain.
The result of this study, which bundles 39 of the most advanced models, is therefore extra relevant.
By: Mick Van Loon
https://www.whatsorb.com/category/climate