During the first days of the current month of April, a historical cold wave hit all over Europe, some believe that it has not been repeated for about a hundred years, as temperatures dropped between 11-18 degrees Celsius from the normal range, which brought people back from the beginning of spring to Winter deepened in hours, and also led to disturbance of early blooming plants and crops in many countries.

(1)

In the same period, some countries in the Arab world were hit by an unexpected heat wave at this time of the year, as Egypt, for example, witnessed a remarkable rise in temperatures to break the barrier of 40 degrees Celsius in some governorates, 5-8 degrees Celsius more than the average, So what is really going on?

Climate whistles

Think of the climatic system as a series of bells that are distributed uniformly over an area of ​​ten square kilometers, each one at a distance of one meter from the other. Here everything may be normal all day long with faint or normal sounds, but if one of the bells gets louder it will stir up its surroundings, which will then whistle in turn to arouse a wider environment, and in a matter of seconds all the bells will be ringing.

The same applies to climate change. The change in average temperatures over decades raises the attention of climate systems in general to become more violent. Here, heat waves become hotter and longer-lived, hurricanes become stronger than usual, droughts become longer, dust storms become more severe, and cold waves become colder than usual. natural.

Although cold waves are less likely to occur in the context of higher temperatures, other climatic disasters allow for exceptional cold waves to occur, at that point let's look at the Polar Vortex, which are continuous and large-scale areas of low pressure that rotate in a hurricane-like manner higher Each pole, extending deep into the atmosphere above, these vortices create a large mass of cold, dense air beneath and surrounding each pole.

In the normal case (3), these vortices are in the form of one coherent cell or dome, and therefore the cold air below is completely confined to the polar circles only, but sometimes these vortices may weaken, here they can be divided into two or more cells, And it begins to travel far from the poles, and when it is very weak it can disintegrate greatly and thus travel south to deeper regions, down to the depth of countries such as the United States of America, or even North Africa and the Arabian Peninsula.

But on the other hand (as you notice in the attached design), the edges of the polar air that extended to the south affect the surrounding weather, attracting the air heights towards it, causing the hot air to travel upwards, and thus the emergence of heat waves in its surroundings, and in fact this is what actually happened In the Arab world, where the outskirts of that cold wave affected the countries of the Maghreb, but it hit the east of the continent with a heat wave.

According to many studies in this range (4,5), climate change causes the polar region to warm, which has a rate of warming greater than twice the rates in the rest of the planet, causing the difference in temperatures between the polar region and lower latitudes to become less, This difference is always the reason for the wind speed in the polar vortex to increase, which facilitates the fragmentation of the vortex with time, and increases the chances of recurring cold waves.

In a study published in the prestigious journal "Science" (6) in February 2021, a research team indicated that it may not only be about the Arctic vortex breaking up, but even if it is not fragmented, there is the ability to expand due to a warming climate, extending regions located in its south It has never been affected by cold air masses from the north, and researchers have found that the polar vortex rings have already significantly expanded over the past 40 years.

It is believed that this was the cause of severe cold waves that some countries experienced during the past few years, for example, in 2019 and 2021, the cold wave in the United States of America was so massive that some areas (such as Chicago) had a temperature lower than the temperature of Mars itself. And there is the cold wave that has been called a "beast from the east" that struck Britain in 2018 and caused complete paralysis in some regions.

As for the Arab region, although these waves are usually less severe because of our relative distance from the impact of these fluctuations in the conditions of the arctic vortex, this did not prevent their impact from extending to us, lowering temperatures to rates not seen for a long time.

the world is changing

Of course, there are no confirmed links between climate change and a specific event, but in general we are sure that climate change increases the rates of anomalies in weather conditions, for example (7), a study conducted by the National Oceanic and Atmospheric Administration (NOAA) in the United States of America had Several different simulation models indicated that climate change may increase the likelihood that the rains of the monsoon season will fail in some US regions, which could spark a multi-year drought that shows no sign of abating, and another study concluded that extremely warm and humid winters on Northwest Russia in 2019 and 2020 was only possible due to climate change.

On the other hand, a research paper found that the odds of a severe heat wave in Western Europe in May 2020 increased 40 times due to human-caused climate change, and that severe wildfires in Siberia during 2020 were caused by non-standard weather conditions increased The probability of its occurrence is up to 80% than it was a century ago as a result of global warming.

In 2018, (8) a study from the journal Science Advances indicated that the rates of severe and fatal weather events in general will rise by up to 50% by the year 2100. Just last year, these phenomena caused the displacement of about 18 million people from their homes, while Climate scientists expect that in just three decades, 200 million people will be forced to do the same because of climate change, so a new term has recently appeared, "climate migrants", to express those who have been pushed by climate change to flee their homes, and the stronger and more frequent the climate strikes. It is likely that the rates of these migrations will increase and their scope will also expand.

The world as we know it is changing, many initiatives have already begun to work to reduce the effects of climate change, and we may one day be able to stop the emissions of greenhouse gases and the pollution of the planet, which has become as close as possible to a factory, one side of which is resources we harvest, and the other is a huge garbage can.

However, the harmful impact of climate change is already present, and we do not know how long it will continue even after we complete our efforts to contain it to the fullest, assuming that the politicians agreed to take it seriously one day!

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Sources:

  • Record-setting cold snap hits Europe, stunning spring crops

  • “Meteorology” warns citizens of the weather today and tomorrow: “wind activity and high temperatures” (details)

  • This Is Why Global Warming Is Responsible For Freezing Temperatures Across The US

  • Warm Arctic episodes linked with increased frequency of extreme winter weather in the United States

  • Reduced North American terrestrial primary productivity linked to anomalous Arctic warming

  • Linking Arctic variability and change with extreme winter weather in the United States

  • Report: Climate change contributed to some of 2020's worst weather

  • Projected changes in persistent extreme summer weather events: The role of quasi-resonant amplification

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