The U.S. agency NOAA (National Oceanic and Atmospheric Administration), which monitors oceans and climate, announced this week that the concentration of gases harmful to the ozone layer passed an "important milestone" when it was reduced to 50% of the level recorded in 1980, when it began to notice the damage generated by human activity to this important part of the planet's atmosphere.

Ozone concentrates in greater volume in the stratosphere, and prevents the incidence of ultraviolet rays from sunlight on living beings and ecosystems on Earth, regulating temperatures and environments. The so-called holes in the ozone layer are regions where gas is decreased, nodded over Antarctica, but also in other regions.

"In contrast to the middle latitudes, progress toward the recovery of the ozone layer over Antarctica has not been as rapid," say the scientists, pointing out that while maintaining the current pace, the recovery of the ozone layer on the continent should occur "around 2070."

"It's great to see this progress," says Stephen Montzka, senior scientist at NOAA's Global Monitoring Laboratory. "At the same time, it's a little humiliating to realize that science is still far from being able to say that the issue of the destruction of the ozone layer has been left behind."

In 1987, the Montreal Protocol was signed to try to contain the amount of ozone-harmful chemicals in the atmosphere, the so-called CFC gases (chlorofluorocarbons), reports Euronews Green.

Previously found in refrigerators, air conditioners, hair spray and industrial cleaning products, these chemicals began to be eliminated to protect the ozone layer. Agreed by all 197 parties, this was one of the first treaties universally ratified in the history of the United Nations.

Different research has pointed out new questions about the knowledge of ozone in the atmosphere. Using different methodologies, a group from Canada draws attention to the "tropical hole" in the layer, which would have depth comparable to the Antarctic phenomenon.

A study published in the journal Nature Climate Change shows impacts on the oceans, pointing out that about a third of the warming observed in Antarctic waters in the second half of the 20th century may be the result of ozone concentration in different atmospheric layers.

Source: Um só Planeta