Ozone layer on road to recovery

Approximately 30 years after the protections of the Montreal Protocol were put into action, there’s more proof that the international contract to safeguard Earth’s ozone layer is effective, as per a fresh by 300 scientists. The large quantity of most ozone-depleting matters in the atmosphere have fallen since the earlier assessment, in 2010, and Earth’s shielding ozone layer is displaying signs of recovery, as per the “Assessment for Decision-Makers,” part of a larger report to be released early next year.
The report is the most recent in a sequence delivered every four years by the international scientific community, headed by the World Meteorological Organization (WMO) and the United Nations Environment Programme (UNEP), and co-sponsored by NOAA, the National Aeronautics and Space Administration (NASA) and the European Commission. The Decision-makers trust on these logical updates and have used them to increase protection of the ozone layer, banning or restricting the use of ozone-depleting substances, for example.
The stratospheric ozone layer, a fragile shield of gas, safeguards the Earth from dangerous ultraviolet rays of the sun. Maximum ozone is located in the stratosphere, far above Earth. The ozone layer acts as a safeguard, absorbing Ultra-Violet (UV) radiation from the Sun and safeguarding Earth’s surface from dangerous volumes of UV radiation. In the 1970s, NOAA researchers started to identify that particular chemicals, including chemicals called Chloro-Fluoro-Carbons (CFCs) and Halons, used extensively in cooling and firefighting, could reach the stratosphere and activate reactions that damages ozone. In 1985, scientists noticed that a seasonal “Ozone Hole” was establishing in the Antarctic spring, NOAA researchers performed a key role in showing that those same chemicals were triggering the hole.
Because of the Montreal Protocol, several ozone-damaging chemicals have been substituted by substances that don’t destroy ozone. Nonetheless, certain new chemicals, including the CFC-substitute Hydro-Fluoro-Carbons (HFCs), are powerful greenhouse gases and could substantially lead to climate change in the upcoming periods. Researchers from NOAA’s Earth System Research Laboratory play a significant part in this subject, testing offered new materials to understand if they are harmless for the ozone layer, climate and the environment.
Key findings:

1. Measures taken under the Montreal Protocol on substances that deplete the Ozone Layer are assisting the restore of the ozone layer to yardstick 1980 levels.
2. The climate benefits of the Montreal Protocol could be considerably offset by projected emissions of HFCs (Hydro-Fluoro-Carbons) utilized to substitute ozone depleting materials.
3. The yearly Antarctic ozone hole has triggered substantial changes in Southern Hemisphere surface climate in the summer. Ozone reduction has contributed to cooling of the lower stratosphere and this is very probable the main reason of noticed changes in Southern Hemisphere summertime circulation over of late decades, with linked effects on surface temperature, precipitation, and the oceans.
4. In the Northern Hemisphere, where the ozone depletion is lesser, there is no convincing link between stratospheric ozone depletion and tropospheric climate.
5. CO2, Nitrous Oxide and Methane will have an growing influence on the ozone layer. What happens to the ozone layer in the second half of the 21st century will mostly be determined by the concentrations of CO2, methane and nitrous oxide – the 3 key long-lived greenhouse gases in the atmosphere. In general, CO2 and methane lead to increase global ozone levels. By contrast, nitrous oxide, a by-product of food production, is both a strong greenhouse gas and an ozone depleting gas, and is expected to become more significant in future ozone depletion.

Month: Current Affairs - September, 2014