The end of March and the beginning of April were similar to the winter months. It was cold in Moscow. Snowstorms raged not only in the Murmansk region, but also in the Volgograd steppes. Snow fell in the Rostov region. Even in Crimea, snow charges were observed.
Millions of people every year - and not only in our country - ask themselves the question: why are scientists talking about global warming, and the thermometer outside the window lives some kind of life and refuses to confirm strict scientific calculations? Winters in many countries are getting colder, summers are lagging for a whole month, and abnormal weather events (snow in May, droughts, hurricanes, tropical showers) have become something ordinary.
We talk about the paradoxical consequences of what is commonly called global warming.
Climatic swing
Last week news came from Greenland. Located in its western part, the Jakobshavn glacier, famous for the fact that once an iceberg broke away from it, which destroyed the Titanic, began to grow in size. But it is considered one of the fastest melting glaciers: the water in the bay where it slides has been getting warmer since the eighties of the last century, and the glacier has lost 150 meters in recent years. But new measurements show that since 2016, the ocean current in this region has become colder, which has allowed the Jakobshavn Glacier to gain growth again.
The climate on Earth is changing, and sometimes in a very unexpected way, so some scientists are already avoiding the term "global warming". They just talk about "climate change". Yes, the average air temperature on the planet since the beginning of the twentieth century has risen by almost a degree, it is pointless to deny it, but the process in different regions is uneven, hence the surprises. Warming is most pronounced in the Northern Hemisphere, or more precisely, in its high (that is, northern) latitudes. Due to the unevenness of warming, the entire climate system becomes unstable, turning into a kind of swing.
“One of the paradoxes of global warming concerns Russians in the most direct way. Against the background of breaking records of global temperatures in our country, in the European part of Russia and in southern Siberia, at the beginning of the XXI century, abnormally cold winters began to be observed more often, - says Vladimir Semyonov, head of the climatology laboratory at the Institute of Geography of the Russian Academy of Sciences, Doctor of Physics and Mathematics. - And it turned out that such weather regimes, oddly enough, are a consequence of global warming in the Arctic. Namely, the rapid reduction in the area of sea ice, primarily in the Barents Sea."
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The surface area of the Arctic ice has decreased by more than 25% since 1970, and the temperature of the permafrost layer has risen by 5 degrees. The decrease in the amount of ice in the Barents and Kara Seas led to the fact that the stratospheric polar vortex weakened over the Arctic, and winters in Russia became more severe. Colds in May or, for example, a long, for two to three weeks, coolness in June - a consequence of the same reasons.
How does this mechanism work?
Funnel around the pole
In our hemisphere, air masses move from temperate latitudes to the north, where the pressure is lower. This movement is due to the difference in the heating of the earth's surface here and there. As the planet rotates around its axis, air currents flowing to its crown begin to swirl around the pole - from east to west. A giant funnel is formed, which is called the polar vortex (or polar cell). Its height is 8-10 km. But above this funnel, another one is formed, reaching the upper boundary of the stratosphere (50 km).
As mentioned, the Arctic is warming faster than other regions. And that's why. The snow melts - the earth is exposed. Ice melts - more open water appears. Both the earth and the water are dark, so they begin to absorb more solar heat, warm up, and thereby intensify the warming process.
As a result, the temperature difference between the pole and the nominal latitude is gradually decreasing. But we remember that due to this difference, air masses move northward and form a polar vortex. And here's the bottom line: the polar vortex becomes weaker, the funnel rotates at a lower speed and loses stability. It begins to chatter slightly, it creates additional waves in the atmosphere, wedging into the continent with frosty wedges, and disrupts the movement of the upper funnel. To the extent that it tears away from it masses of cold air, which rush to the south, get stuck for a long time on the territory of Russia and force us to torment the forecasters again and again: "And you call this global warming?"
Will the Gulf Stream stop?
The climatic paradoxes do not end there. Vladimir Semyonov gives two more examples:
“We see sea ice disappearing in the Arctic before our eyes. And at the same time, the area of sea ice around Antarctica is slowly but growing, despite warming. One hypothesis is that this is due to natural fluctuations in ocean circulation in the southern oceans.
The mass of the largest glacier on Earth is also growing: the Antarctic. This is due to the increased precipitation over the glacier. And in terms of its contribution, this increase exceeds the melting of ice due to the greenhouse effect."
Since the mid-nineties, a climatic horror story has been in circulation, which also looks like a paradox. We are talking about a model predicting a stop (and even a reversal) of the warm Gulf Stream. After that, they say, Europe will be covered with a glacier, and its population will have to hastily move to warmer regions. Fortunately, this hypothesis has not been confirmed.
“The stopping of the so-called 'oceanic conveyor' in the North Atlantic, carrying oceanic heat from southern latitudes, was predicted using idealized models,” says Vladimir Semyonov. “This gave rise to catastrophic climate change scenarios, rumors of a“new ice age”and the release of the Hollywood blockbuster The Day After Tomorrow, which was filmed for these reasons. However, further studies using more sophisticated models showed that such a scenario is impossible with global warming."
It is a pity that the same cannot be said about other surprises prepared for us by global climate change.
Author: Dmitry Pisarenko
