The inhabitants of the middle latitudes of the Earth are accustomed to four traditional seasons: winter, spring, summer and autumn. Such periods are clearly expressed in two climatic bands stretching across the planet from 30 to 60 degrees latitude north and south of the tropics, including much more varied weather than at the equator, where there are mainly only two seasons: hot and dry, and also the rainy season. The same goes for the upper latitudes, where every year comes a cold winter with long dark nights and a slightly less cold summer with longer daylight hours. How will climate change affect this eternal cycle of nature?
So the summer has passed, as if it never happened
Today there are two ways to determine the change of seasons. The astronomical method is based on the change in the length of the days, which is due to the relative tilt of the earth's axis. In this system, winter is the period between the winter solstice on December 22, that is, the shortest day of the year, and the vernal equinox, when day and night are approximately equal, which occurs around March 21. Spring lasts from the vernal equinox to the summer solstice on June 22, or the longest daylight hours. Summer continues until the autumnal equinox on September 23rd, and autumn closes the cycle at the winter solstice.
There is also a meteorological method for determining the seasons, which has been around since the mid-1900s and is much simpler. The year is divided into four parts by months, so that winter is the "three white horses" December, January and February, spring is March, April, May, and so on. A 1983 study found that the meteorological method works more accurately in the continental regions of the northern hemisphere, while the astronomical method is more consistent with weather changes over the oceans in the southern hemisphere.
Warmer, even warmer
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Climate change is gradually making adjustments to the traditional concept of four seasons. Scientists have found that as the planet warms up, the tropics expand by 0.1-0.2 degrees of latitude every decade, so little by little the equatorial "two-season" is taking over territories where there used to be four seasons. But even in regions with four seasons, the weather and average temperatures vary. This can translate into earlier transitions from cold winters to warm spring days, and winters themselves are getting shorter and milder.
However, scientists are in no hurry to say that soon we will have only two seasons. All four will remain, only the timing and duration will be different. Summer will become longer and warmer, while winter, on the contrary, will shrink. However, the "transitional" seasons - spring and autumn - are not going anywhere.
So "The Seasons" by Pyotr Tchaikovsky will not lose their relevance!
Anton Ivanov