Earth's point of no return or global warming


In recent years, the climate on Earth has been noticeably changing: some countries suffer from abnormal heat, others from too harsh and snowy winters, unusual for these places.
Environmentalists talk about global climate change, including an increase in the average annual temperature, causing the melting of glaciers, and an increase in the level of the world's oceans.
Scientists identify several climatic risk factors that most seriously affect the state of the planet: deforestation and the death of the Amazon jungle, the disappearance of Arctic ice, the slowing of the Atlantic circulation, fires in taiga forests, the extinction of coral reefs, the melting of glaciers in Greenland and permafrost, the loss of glaciers in East and West Antarctica. It is no exaggeration to say that the climate in various parts of the planet is becoming extreme, less and less balanced.

And every year the situation worsens. The average temperature on the planet currently exceeds the pre-industrial level by 1.1 degrees Celsius. Experts say that by 2040 this indicator can reach 1.5 degrees Celsius. This, they say, will lead to the destruction of the ice sheets. Then the level of the world's oceans will rise by 10 meters, and fires and permafrost melting will increase carbon dioxide emissions into the atmosphere. This, in turn, according to scientists, will only accelerate warming.
In 2015, the Paris Agreement was adopted, which was signed by 196 countries of the world. It assumes that due to the limitation of greenhouse gas emissions, the temperature increase caused by anthropogenic impact on the climate will not exceed 2 degrees Celsius. This value is considered a relatively safe threshold at which the effects of climate change will not be so serious. If countries fulfill their obligations to reduce greenhouse gas emissions (and there are big doubts about this), global warming will be at least 3 degrees Celsius. Some economists, based on the fact that climatic points of no return are very unlikely (although catastrophic), believe that a warming of 3 degrees Celsius is optimal from the point of view of costs and results.


Scientists used climate models to determine the "point of no return", after which it will no longer be possible to limit warming. Standard climate models allow, in particular, to determine how the Earth's climate will change depending on the scenario of human actions — how greenhouse gas emissions will decrease or increase.
In their research, they showed that there are strict deadlines for climate protection actions (the last or deadline), and came to the conclusion that there is very little time left until the moment when the Paris goals (1.5 and 2 degrees Celsius) will become unattainable even with a sharp reduction in emissions.
Negative emissions, that is, the removal of CO2 from the atmosphere, for example, by capturing and burying carbon dioxide, would help to postpone the deadline for 6-10 years, but so far such technologies exist only in the form of prototypes. And some experts, however, are concerned that such technologies can do more harm than good, and to remove one ton of CO2 from the atmosphere, you need to spend $ 600.
If we increase the required probability (limiting warming) to 95%, the point of no return for two degrees Celsius shifts to 2022, and for one and a half degrees it has already been passed. Understanding the time frame in which it is necessary to start acting will help bring humanity to a safe climate trajectory, and at the same time, scientists call their calculations optimistic, since they do not fully take into account the impact of other greenhouse gases besides CO2.