Humanity must learn to adapt to the ongoing climatic changes on the planet. This opinion is shared by a senior researcher at the laboratory of climate theory at the Institute of Atmospheric Physics named after A. M. Obukhov RAS Alexander Chernokulsky. In an interview with RT, the scientist said that throughout the history of the Earth, various factors influenced the global climate: changes in solar and volcanic activity, global restructuring of ecosystems, parameters of the earth's orbit, the fall of large meteorites. Today, in his opinion, anthropogenic impact is coming to the fore. The scientist also noted the importance of political and economic components in environmental issues.
It is widely believed that human activities have led to serious climate change on the planet. How scientifically justified is it?
- The first studies on the relationship between the greenhouse effect and temperature on the planet were carried out by scientists in the 1930-1950s. In the 1970s-1980s, the understanding was finally formed that burning fossil fuels increases the greenhouse effect.
If in the 1990s, the confidence of scientists that warming is associated precisely with the burning of fossil fuels was about 90%, now climatologists are 99.9% sure of this.
In general, various factors can affect the global climate: changes in solar and volcanic activity, global restructuring of ecosystems, parameters of the earth's orbit, the fall of large meteorites, finally. For example, the Little Ice Age, which caused a cooling on the Earth in the XIV-XIX centuries, was associated with increased volcanic activity and low luminosity of the Sun. Now the volcanic activity is rather weak, the change in solar activity from cycle to cycle is also insignificant, changes in the parameters of the orbit for such a short time are practically zero.
Climate models show that modern warming can only be explained by taking into account the burning of fossil fuels.
Where did the term "greenhouse effect" come from?
- At the beginning of the 19th century, Joseph Fourier suggested the existence of the greenhouse effect. He calculated the equilibrium temperature that a planet should have when it receives energy from the Sun, and found that the temperature of the Earth is higher than it should be. Fourier suggested that there are some gases in the atmosphere that additionally emit long-wave radiation. The term “greenhouse effect” appeared at the beginning of the 20th century, but the comparison with a greenhouse is not entirely correct, because convection is locked in a greenhouse. Whereas long-wave radiation is locked in the earth's atmosphere.
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In the mid-19th century, John Tyndall experimentally proved that water vapor and carbon dioxide are the main greenhouse gases. Later, Swedish scientist Svante Arrhenius was the first to calculate that if the level of CO2 in the atmosphere increases, it will lead to warming. As a resident of a server country, this hypothetical possibility only pleased him.
What is the most important evidence of human impact on climate?
- The evidence that formed the basis for understanding that humans really affect the climate appeared in the middle of the 20th century. In the late 1950s, the Mauna Loa Observatory in Hawaii opened, where they began to observe the concentration of carbon dioxide in the atmosphere. Scientists have seen how fast it is growing. Observations began when the level reached 315 ppm, today the figure is 415.
In the 1990s, work appeared on the study of Antarctic ice cores - roughly speaking, columns of ice extracted from a glacier. Ice contains air bubbles, and its chemical composition can be used to determine the composition of the atmosphere in the past. It was found that the concentration never rose above 280 ppm in the last 800 thousand years, it always fluctuated in the region of 180-280.
At the same time, the cycles of glaciation of the planet, associated with changes in the parameters of the Earth's orbit, were investigated - this is also an important factor influencing the climate (the so-called Milankovitch cycles). Then there was an understanding that the level of CO2 is growing rapidly. In addition, in the middle of the twentieth century, an isotopic analysis of carbon dioxide in the atmosphere was carried out and it was found that its composition increased the amount of light carbon isotopes that are released from the combustion of coal and oil. In addition, various mathematical climate models demonstrate that modern warming can only be explained in terms of fossil fuel combustion.
How strongly do we influence the climate?
- Warming is the result of human activity. If it were not for it, then the average temperature on the planet would be one degree lower.
For the first time, politicians started talking seriously about global warming after the release of the report of the Intergovernmental Panel on Climate Change (IPCC) at the UN, in which the increase in temperature on Earth was indicated by the fault of humanity. At the same time, opponents of the theory of global warming call the experts' conclusions a pseudoscientific fraud and believe that the topic of global warming is overheated for political purposes … However, climate issues are now one of the most pressing in the world. This topic became the main one at the 50th anniversary summit in Davos
- After the 1970s, there was a wave of scientific papers, articles on the topic of climate change. The first IPCC report appeared in 1990 to accumulate all the knowledge gained at that time on this issue. IPCC is an international group of experts on climate change, created by the World Meteorological Organization and the United Nations. The IPCC has only 25-30 people, but thousands of scientists (authors, reviewers) are involved in writing the assessment reports. The IPCC prepares resumes for politicians, and issues a politically neutral slice of modern knowledge. Their conclusions about the human influence on the climate are unambiguous.
Then politicians, based on such reports, decide for themselves what to do: adapt or mitigate the effects of climate change. The Kyoto Protocol, the Paris Agreement and the Davos summit are attempts to reach an agreement by the whole world.
Recently, there is a feeling that climate change has already led to insoluble problems that are only getting worse: destructive hurricanes regularly rage in America, Europe is periodically flooded, and forests are burning in Australia. Is this really so, or have we just become more informed thanks to the proliferation of mass communications, and have there always been similar problems on the planet?
- There are three processes to consider here. First, we have become more informed, this is a fact. The second process - humanity has become more vulnerable, as people began to settle in the floodplains of rivers, on the shores of the oceans. The third process is an increase in the number of dangerous climatic phenomena.
There have not been such fires as in Australia, for example, in the entire history of meteorological observations. Severe drought and record heat have led to such consequences.
Severe drought and record heat have led to wildfires in Australia unlike any other in the history of meteorological observations.
Of course, humanity is adapting to the ongoing changes. There is a problem with the flooding of tropical islands, "low" countries. The question remains whether they will be able to adapt and build, for example, high ramparts, or their adaptation will consist in the fact that they will negotiate with some country on the purchase of territories and, accordingly, move there. In any case, climatic migration is inevitable.
It was recently reported that at the beginning of 2020 in Russia there will be a state standard for adaptation to climate change. On January 4, the first stage of the national plan for adaptation to climate change until 2022 was approved. What are we preparing for? Perhaps we should rejoice at the softening of the climate in Russia, where it is usually winter for almost six months?
- In fact, scientists know what is happening now. We are influencing the climate, we have increased the greenhouse effect, and then we will continue to warm with small pauses. The last such pause in global warming was 5-15 years ago.
There are specific estimates of temperature changes for each region. It should be understood that carbon dioxide emission depends on the structure of energy consumption, industry around the world. We are tied to the models of economists, who give several scenarios for the future. Depending on these scenarios, for each region, a certain ensemble of temperature distribution, the probability of heavy precipitation, flood height, etc. is given, and then it is again up to economists and politicians to calculate all the pros and cons: how much money to spend on adaptation, mitigation, policy change on the climate to rebuild and prepare the economy.
Our country must count both the pluses and minuses. It is necessary to adapt to the pluses, realizing, for example, that for agriculture in certain regions there will be more favorable conditions. There are pros and cons, but different factors and from different areas. You need to develop a methodology to compare all the pros and cons. Conventionally: how to compare the advantages of the passage of container ships without icebreaker escort along the Northern Sea Route and the disadvantages of the destruction of infrastructure due to thawing of permafrost? There are many such examples. I have not yet seen work comparing such different consequences.
Authors: Arseny Skrynnikov, Alyona Medvedeva