A climate summit has started in Paris, at which the powers that be will agree on what to do with global warming.
Why the existing problem of climate change on the planet does not have a full-fledged solution, it will get colder or warmer on Earth in the short and long term, and what will happen to Russia and its territory in the foreseeable future - read in this review.
Everything is bad
There is nothing funny about the concern about carbon dioxide common to Western civilization. Carbon dioxide (CO2) does block infrared radiation, especially in the 13.9 micrometer range, and although only a minority of the greenhouse effect is attributable to this gas, its presence "regulates" the atmosphere as a whole.
The presence of carbon dioxide heats the planet, and heating increases the amount of water vapor in the Earth's gas envelope and further increases the temperature. The complete burning of all known fossil fuel reserves means a 58-meter rise in sea level over a thousand years, complete melting of ice in Antarctica, inundation of millions of square kilometers and a rise in global temperatures by several degrees.
In such conditions, the extinction of polar bears, penguins and corals can be expected.
Fearfully? Most Russians will answer this question in the negative. Some will argue with irony: polar bears as a species appeared a million years ago, that is, they obviously experienced a climate much warmer than the present; penguins have found a time when there was no ice in Antarctica; corals have gone through an era when the coast of the Arctic Ocean was warmer than it is today on the Yalta embankment.
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The most savvy argue with knowledge: ten thousand years ago, the boreal period ended glaciation, raising the temperature by seven degrees Celsius in 50 years, and today we are frightened by the temperature rise until 2100 by only 2.7 degrees Celsius. And what is the danger?
Greed has ruined the fern
Man is not the first species that has managed to turn the climate of the home planet. Moreover, while its influence is much more modest than that of previous climate makers. Now Azolla primaeva is just a centimeter-long floating fern that can easily be confused with duckweed. But 49 million years ago, he accidentally caused a mini-apocalypse.
Then, on the surface of the Arctic Ocean, the average annual temperature (13 degrees Celsius) was equal to the Yalta one, the straits connecting it with other oceans narrowed, because of which the water in the ocean did not mix. Warm shores were irrigated by rains, and rivers brought many nutrients from land to the ocean.
Azolla primaeva algae on the Canning River in Australia
Azolla came along with fresh rainwater, and since this water is lighter than sea water, it formed a fresh layer several centimeters thick on the ocean surface. And then it was discovered that if the azolla shines for more than 20 hours a day (polar day), then it doubles its mass every 48 hours.
As the plants grew, they pulled carbon dioxide from the atmosphere, and over 800 thousand years reduced its concentration from 3,500 parts per million to 650 parts per million. It would have stretched more, but the average surface temperature of the Arctic Ocean dropped by 20 degrees, and the azolla froze. As a result, the planet received permanent ice caps at the north and south poles.
The conclusion is simple: one species that has seized huge resources and has no natural enemies can multiply so quickly that it will send the ecosystem to its forefathers before it can stop its own greed. Before the outbreak of Azolla breeding, there was seven times more carbon dioxide than it is now, but a man, who today is also devoid of enemies (like the Azolla once), is quite capable of correcting the mistakes made by the fern.
Climatic multi-port
One can often hear the opinion that for Russia with its harsh climate, warming is more likely a blessing. Its supporters are confident that although some of the gas pipelines and polar cities will suffer from the melting of permafrost, a very small area will go under the water, but the middle zone will finally acquire a climate similar to the modern Western European one.
In fact, the reality of warming is much more complex. The rise in temperatures leads not only to the degradation of permafrost, but also to the melting of methane hydrates, a process that results in large voids under the soil, and then craters. According to scientists, this could threaten Siberian cities.
In the extreme south, warming leads to an increase in evaporation from the water surface, which is why events similar to the catastrophic flood of 2012 in Krymsk became possible on the Black Sea coast.
But these are all small things compared to the larger threat. Strong warming leads to unpredictable changes in the humidification regime. A couple of million years ago, broad-leaved forests grew in the Arctic, and the Sahara was green and habitable.
The subsequent cold snap changed the situation dramatically: desertification processes began, which sometimes reversed during the next warming. However, sometimes a cold snap, on the contrary, led to the humidification of the Sahara - for example, during the last glaciation, the present desert was a savannah, whose inhabitants painted crocodiles and hippos on the walls of caves.
The desert came to its present state after the warming, which began in the Holocene, and the longer this era lasted, the drier the Sahara became: five thousand years ago there was an extensive system of rivers.
So the climate is too complex for modern climatological models to predict exactly how humidity will change in any part of the world as global temperature rises further.
It is known for sure that in recent years the number of forest fires in European Russia has been growing, and the precipitation is such that the level of groundwater in the Central Federal District is significantly lower than the average long-term values. And on the Caucasian peaks, there is less and less snow every year, which is why in some places everything is not all right with water resources in the region.
In other words, warming can really lead to the fact that Voronezh will become warmer than Paris. But without precipitation, this warming can do more harm than good.
Diamonds in the sky
An unpleasant feature of all these processes is that it is either difficult to stop them (try refusing to burn the same gasoline or gas) or dangerous. Recently, a group of climatologists proposed spraying diamond nanoparticles into the stratosphere, which would scatter sunlight and reduce global temperature.
The method, which they reasonably call the safest method of cooling the Earth, is bad in only one thing: it is a rather risky experience over seven billion people at once.
The fact is that the climate of a planet of our type near a star like the Sun is characterized by a positive feedback system that is not characteristic of most planets in the Universe. Ice caps, which increase as global temperatures drop, reflect more sunlight into space, further cooling the planet.
Other feedbacks are also included here: the lower the temperature, the less water vapor per unit volume of air, and it is water vapor that accounts for 70 percent of the total greenhouse effect.
But that's not all: as the ocean water cools, the amount of carbon dioxide that can be dissolved in it increases significantly. The seas literally suck the greenhouse gas out of the atmosphere, which is why they risk cooling even more, and then absorbing even more carbon dioxide.
It is not hard to guess that such systems with positive feedback can turn even moderate cooling into an avalanche of events that dramatically change the climate.
Barack Obama's speech at the climate summit in Paris
And the most unpleasant thing is that it is not known what can happen after such an artificial "diamond" cooling. It is not worth assuming that precipitation will return to the place where it decreased due to warming. The climatic history of the Earth shows that the Sahara can turn from the savannah to a desert both during warming and during the ice age, and it was not possible to reliably identify any regularity regulating this process.
Other seemingly safer methods of compensating for the growth of greenhouse gas emissions are also proposed. Thus, a group of German scientists proposed planting a jatrofa curcas plant in the same Sahara. For 20 years of active life, one hectare planted by him "draws" 25 tons of CO2 from the atmosphere per year.
To fully compensate for all anthropogenic emissions, it is enough to plant 13 million km2 with jatropha, which is approximately equal to the area of terrestrial deserts. Since the euphorbia plant can indeed reproduce successfully even in the driest conditions, the project looks both realistic and environmentally friendly on the outside.
Alas, the reflectivity of the desert surface is significantly higher than that of the same desert, but planted with shrubs and trees. By planting eight percent of the Earth's land area with plants (an option comparable in cost to spraying diamonds), we will increase the total heating of the Earth by the Sun by almost one percent - and this theoretically could heat the planet even more than carbon dioxide emissions.
As we can see, the climate is a complex system, moreover, it is not yet fully understood. In such conditions, an attempt to repair a delicate mechanism with a sledgehammer can do more harm than good. All this makes the chances of approving active strategies for anthropogenic global cooling very risky.
It is difficult to imagine how something with such unpredictable consequences could be agreed at the UN level. So it is too early to wait for the appearance of diamond dust over our heads.
War with the Mills
The prospects for the conservative scenario of combating global warming are also unclear. It is proposed to reduce carbon dioxide emissions as much as possible, but will that help?
A recent book by a team of renowned climate scientists asks the question: Can we reliably distinguish between current global warming and the effect caused by the usual variability of the Earth's climate?
As noted in the publication, "an important conclusion of the study is that natural climate changes on a scale of decades or more are so great that, without taking into account their influence, one can come to erroneous estimates of the sensitivity of the climate to anthropogenic impact."
Adélie Penguin in Antarctica
There are many examples of this kind of non-anthropogenic warming. It is well known that many trees grew in Greenland a thousand years ago, while the Thames was regularly frozen in ice four hundred years ago for the whole winter. About seven thousand years ago, natural warming occurred, even more extensive than the current one: the sea level was then three meters higher, and one meter higher than that which the fighters against global warming are scaring humanity with by the end of the 21st century.
If you ask climatologists about the causes of all these events, then among the various answers will necessarily be the phrase "natural variability." Other scientists, not finding the reasons for such climate changes, even try to deny the very fact of such warming and cooling - this is evidence of how insufficient human knowledge about them is.
In the Ammassalik Fjord area in Greenland
Unfortunately, there were no accurate meteorological observations in these epochs, but from indirect signs like sea level it is obvious that the earth's climate can change rapidly and strongly without any anthropogenic carbon dioxide emissions, and for reasons that can only be guessed at so far.
Climatology is a science in which a large-scale experiment is very difficult to conduct, not to mention that it is hardly worth it. There are no final answers to these questions so far, which means that humanity is in a state of uncertainty.
Global warming is a reality, and although there has been no increase in temperatures since 2000, this does not mean that the summer will not become even drier, and floods in the Far East and the Black Sea coast - more frequent. However, there are no reliable ways to stop the warming, or even confidence that we can do it at all.
All that is in our power is to be prepared for an unpleasant development of events and not to aggravate the situation too much both by an increase in greenhouse gas emissions and by not fully thought out steps to compensate for them.