The ozone layer is not recovering due to chemicals


The recovery of the hole in the ozone layer (a shield from the atmosphere that protects living beings from ultraviolet rays) can take at least 30 more years than originally anticipated, all due to increased emissions of a chemical used in labeled substances as “ozone friendly”.

This warning was given by a researcher at the University of Lancaster, UK, who studies how the chemical changes in the atmosphere influence the climate on planet Earth.
According to Ryan Hossaini, dichloromethane (CH₂Cl₂) is a colorless, volatile liquid, generally used as an industrial solvent or paint removal product, to decaffeinate coffee, to prepare plant extracts, to produce aerosols or polyurethane foams, and to construct air conditioners or Refrigerators.

The use of this chemical in industry has increased greatly since chlorine and chlorofluorocarbon (CFC) products have been more controlled by the Montreal Protocol (the industry has emitted one million tonnes of dichloromethane per year). Dichloromethane concentrations in the lower layers of the atmosphere have doubled since 2004.

Even so, many of the products containing dichloromethane are labeled as “ozone friendly”, which may not correspond to reality. Dichloromethane is a substance increasingly used to produce a molecule often used to replace chlorofluorocarbons (CFCs) in industry, difluoromethane (CH2F2). The problem is that when it reaches the atmosphere, dichloromethane begins to deteriorate after five months, thus releasing chlorine which in turn destroys ozone when it reaches the outermost layers of the atmosphere.

The Montreal Protocol was a treaty signed in September 1987, in which the signatory countries undertake to replace ozone-depleting chemicals with less harmful ones, all in an attempt to reduce the hole that had been detected above the ozone layer. Antarctica. Of all the chemicals that are harmful to the environment, 15 are types of chlorofluorocarbons. Among them is not dichloromethane since, at the time, these molecules were thought to be destroyed long before they reached the stratospheric layers (the outermost of the atmosphere, where the ozone layer is).

Recent data say that dichloromethane is more harmful than we thought.

According to Ryan Hossaini, for the time being, this substance accounts for less than 1% of the concentration of chlorine in the lower layers of the atmosphere. However, by 2050, following this rate of use, a quarter of that concentration may have been caused by dichloromethane.

Ryan Hossaini went on to say that “the prospect that the ozone hole will be closed in 2065 does not take into account the increase in dichloromethane emissions: if we take these emissions into account, the ozone hole can only Best prospects, in 2095”.
It is believed that the continent that emits more dichloromethane into the atmosphere is Asia.