We live in a world where, although it may seem incredible, what happens here can have repercussions on the other part of the globe. As for the climate, we already spoke in a article that the large amount of water produced by rainforests regulates temperatures around the world.
Now, a study published in the journal Nature Climate Change, has discovered that, by continuing to emit carbon dioxide into the atmosphere, the North American monsoon could weaken. If they do, the consequences could be dramatic.
What is the monsoon?
To understand the seriousness of the matter, let's explain what monsoons are. A monsoon is a seasonal wind that is produced by the displacement of the tropical rain belt, which oscillates from the north of the Tropic of Cancer to the south of the Tropic of Capricorn in the course of the year. This belt carries rains in the southern hemisphere from October to March, and in the northern hemisphere from April to September.
While in one part it rains copiously, leading to very serious floods, in the other, on the contrary, the dry season is experienced.
How is it produced?
They are caused because the earth cools and heats up faster than water. There is the summer monsoon, and the autumn monsoon. The first is formed due to the fact that the earth reaches a temperature higher than that of the oceans, so that the air rises towards the atmosphere causing a storm or area of low pressure. The wind blows from areas of high pressure to areas of low pressure to try to equalize both pressures, thus creating a strong wind that blows from the ocean. Finally, rain occurs due to the elevation and cooling of the air in the mountains.
During fall and winter, the land cools more quickly, but the ocean takes longer to cool, so temperatures remain high. Therefore, the air rises, creating an area of low pressure over the ocean, and winds blow from the land toward the ocean. Since the temperature difference between the two is much smaller than in summer, the wind blowing from the high pressure to the storm is not as constant.
Why might the North American monsoon weaken?
Monsoons are very sensitive to greenhouse gases, according to the scientists authors of the study Salvatore Pascale, William R. Boos and their team. Using a global climate model, they have found that If carbon dioxide emissions were to double, the North American monsoon would weaken, specifically in the southwestern United States. Why?
The stability of the atmosphere, and therefore the weakened convection caused by the uniform warming of the sea surface, appear to be responsible for the reduction in precipitation. This change in climate is a clear example of the impact of CO2 emissions on the North American monsoon.
Thus, adaptation measures will have to be taken and, above all, make better use of water resources. Furthermore, it is important to consider how greenhouse gas emissions impact these weather patterns.