The IPCC is a structure at the UN, established in 1988, after it became clear that the Earth's climate is not something given once and for all, but a changeable system, which is significantly influenced by humans. The IPCC reports provide the most comprehensive information on climate. They are prepared by hundreds of scientists from all over the world, analyzing thousands of scientific papers with the results of observations, computer simulations, and carefully check each formulation.
The conclusions from the IPCC assessment reports are taken into account in the preparation of international treaties necessary in order to avoid a catastrophic future for civilization and the entire planet. The reports are released in parts: the physical foundations of climate change, the impact on natural systems and adaptation, climate change mitigation. The last one was released in 2013-2014. After that, the Paris Climate Agreement was signed, the main goal of which is to stop the increase in the average global temperature at a level not higher than 2 degrees compared to the pre-industrial era and to do everything possible to keep it within 1.5 degrees.
The published report of Working Group I is part of the Sixth Assessment Report of the IPCC, which has been prepared since 2016 and will be fully completed in 2022. “Most importantly, the conclusions of previous reports that the climate as a whole are warming have been confirmed and that the main cause of warming is anthropogenic greenhouse gas emissions,” explains one of the authors of the report, Alexei Eliseev from Moscow State University and the Institute of Atmospheric Physics.
A new report from the IPCC says that since the 1850s and 1900s, human activities have increased the average global temperature by about 1.1 degrees. Each of the past four decades has been warmer than the last and any other in 170 years. The climate is changing in all regions. “If we take the current level, then we will choose the available emission for one and a half degrees in 15 years, and for two degrees - in 30 or 35 years,” says Aleksey Eliseev.
As much carbon dioxide, as now, in the atmosphere was not the last 2 million years, methane and nitrous oxide - 800 thousand years. Without a sharp and large reduction in greenhouse gas emissions, the goals of the Paris Agreement are unattainable. You need to act immediately. It would be possible to stabilize the global temperature in 20-30 years, but in any case it will rise until at least the middle of the 21st century. According to even the most optimistic scenario discussed in the report, by the end of the century it will be, on average, warmer than it is now. For this, greenhouse gas emissions should be no more than absorbed by ecosystems and with the help of technologies (while such technologies exist only in the form of prototypes). But if emissions do not decrease, but, on the contrary, increase significantly, then it may warm by more than three degrees or more.
Climate warming sometimes deceives intuition - suffice it to recall the recent frosts in Texas - and is manifested not only by an increase in average temperature (due to warming, climate variability is increasing). The water cycle is also increasing on the planet and its spatial characteristics are changing. Because of this, powerful downpours are pouring in some places, while drought is increasingly common in others. In high latitudes, precipitation is likely to be even more, and in the subtropics - less. The higher the global temperature rises, the more often extreme weather will be set.
Another author of the report, Olga Zolina from the Institute of Oceanology of the Russian Academy of Sciences and the Alpine University of Grenoble, considers the conclusion about extreme weather to be the most important: “Heat waves, droughts and extreme precipitation are very, very serious. We saw this in the summer: Germany, Belgium. This has happened before, but not so often and not so much, but it will be even more often and even stronger, and it is not known where. We cannot stop this, no matter what we do."
The report lists processes that cannot be reversed even after centuries, and possibly millennia.The oceans will continue to heat up, acidify and lose oxygen, and the sea level will rise. Permafrost will melt and release even more carbon into the atmosphere. “For people, the most critical is the rise in sea level. It would seem that from 1902 to 2018 it increased by 20 cm, but it will continue to grow, grow, grow, and we will not do anything about it,” says Olga Zolina.
The report also mentioned unlikely events such as a rapid decrease in the ice cover of Antarctica, which can nevertheless happen. Such events can strongly affect the climate system and cause a domino effect with a poorly predictable result. Aleksey Eliseev gives an example: “A hypothetical, but theoretically most probable situation - warming will weaken the meridional circulation of the ocean. Part of it is the Gulf Stream, which noticeably warms the climate of Europe and Eurasia, at least to the Urals. Northern Eurasia will start to get colder, and the tropics will start to heat up. Because of this, the forests of the Amazon may perish with additional release of carbon dioxide into the atmosphere. The issue has not been studied very well, threshold values have not yet been brought - this is a task for the future."
Russia, like other countries, is not separately mentioned in the report. "Russia is a very large country, has a vast territory with different climatic, economic, demographic conditions. In some places climate changes are favorable, and in some places they are not. Facilitation of navigation along the Northern Sea Route due to the degradation of sea ice is, rather, favorable for development The Paris Agreement provides for national adaptation plans. In Russia, such a plan has been adopted, the development of a second stage is planned. The attitude [to climate change] is quite serious, "says Sergey Semyonov from the Institute of Global Climate and Ecology, vice-chairman of Working Group II. Part of the Sixth Assessment Report of this group will be released in 2022.
But if we talk not only about Russia and not about plans, but about what has been done, then there is nothing to boast about. "There is not a single good news in the report, nothing at all. We only made things worse. If we get down to [the case] right now, we can only affect the rate of change. The rate could be so high that by 2030 the temperature will be [by] 1, 5 degrees [higher compared to pre-industrial times], and this is no longer a joke, "Olga Zolina sums up.
All three interviewed experts emphasize that the IPCC is not involved in politics. "The style of this group is this: it is said that if greenhouse gas emissions are arranged like this, then climate change will occur this way. Then it is not the concern of climatologists, but politicians, public figures, civil society. Governments and peoples must choose, what climatic future do they like, "says Sergei Semenov. Alexey Eliseev continues: “Someone will see climate change, when the whole Kuban is in drought and wheat stops growing there, and for someone the average annual temperature is half a degree higher throughout the Earth. But I know for sure: when it comes to serious consequences, there will be late".