If the world is warming up, why is it so cold in winter?

As climate change increases our planet's temperatures, warming has affected winters faster than summers. However, when temperatures drop below freezing, many people, including US President Donald Trump, ask, "If the Earth is warming up, why is it so cold in winter?"

The answer lies in the difference between the local weather and the climate in general.

The climate refers to how the atmosphere behaves over a long period, while the weather describes what happens in a much shorter time. In a certain way, the climate can be considered as the sum of long meteorological periods.

Or, if we use an badogy: the weather represents the amount of money you have in your pocket today, while the weather is your net worth. A billionaire who has forgotten his wallet one day is not poor, just as a poor man does not become rich if he suddenly realizes an unexpected profit of a few hundred dollars. The important thing is what happens in the long run.

Even if one day you are colder than usual, the entire planet is more often warmer than the historical average.

For example, in December 2017, the weather was exceptionally cold in many parts of the United States; they had temperatures between 8 and 16 degrees Celsius cooler than normal, but the world generally had warmer conditions of 0.5 degrees above average from 1979 to 2000:

Climatologists expect the world to warm an average of 1 to 3 degrees more by the end of the century – depending on how quickly greenhouse gas emissions rise – but that should not mean the end of the century. Winter There will always be historically minimal temperatures, but they will be more and more spaced.

According to a study published in 2009, the United States had about the same number of historical maximums as the temperature minimums observed in the 1950s, but in the 2000s it was twice as high as historical minima. There were still waves of cold, but they became much less frequent.

Some of the recent cold spells were caused by a climatic phenomenon called the polar vortex, referring to circular wind bands near the poles. More and more evidence suggests that the polar vortex occurs more frequently outside the Arctic region due to changes in the current due to warming of the atmosphere. These changes allow the icy air to escape from the Arctic and infiltrate south.

Some world politicians have already tried using the cold waves to badert that global warming is not the case. US President Donald Trump has a habit of being skeptical about climate change on Twitter and has published comments on "climate change" or "global warming" more than a hundred times since 2011. Before becoming president, he said that the change The climate was a hoax and claimed that the idea had been perpetuated by the Chinese.

In 2018, he went back on his comment saying, "I do not think it's a hoax, I think that there is probably a difference, but I do not know if this is caused by the l? humanity."

Hundreds of scientific organizations indicate that human activities are primarily responsible for global warming.

Brad Plumer, Lisa Friedman and Hiroko Tabuchi collaborated on the report.

* Copyright: 2019 The New York Times News Service