Science

Global Plan To Fix Ozone Hole Is Working

Global Plan To Fix Ozone Hole Is Working”

Discovery of the hole in 1985 elevated concerns about damage to the ozone layer, the invisible barrier in the Earth's stratosphere that protects humans from the sun's harmful ultraviolet rays. Later amendments to the Montreal Protocol completely phased out production of CFCs.

Previous attempts at charting the ozone layer's ebb and flow have centred on the physical size of its hole, so this study marks an exciting deviation from conventional monitoring. These compounds include chlorofluorocarbons (CFCs), halons, carbon tetrachloride, and methyl chloroform.

Strahan said the recovery would continue at a slow pace because CFCs are long-lived molecules that persist in the atmosphere for decades.

Atmospheric scientist and lead author Susan Strahan from NASA Goddard Space Flight Center in Greenbelt in Marylandm said in a statement that, "We see very clearly that chlorine from CFCs is going down in the ozone hole, and that less ozone depletion is occurring because of it". When Antarctica is bathed in sunlight in the Southern Hemisphere's summer, CFCs break down and produce chlorine, which then break apart ozone atoms.

"During this period, Antarctic temperatures are always very low, so the rate of ozone destruction depends mostly on how much chlorine there is", Strahan said.

NASA’s *Aura* satellite which measures atmospheric chemical compositions
NASA’s *Aura* satellite at about 705 km above the Earth measures atmospheric chemical compositions

Using a special instrument designed by scientists at NASA's Jet Propulsion Laboratory in California, the agency's Aura satellite has measured declines in the concentration of ozone-killing chlorine.

In 1987, in what was heralded as a major diplomatic feat, the world's countries came together in Canada to sign the Montreal Protocol, an global treaty aimed at gradually eliminating the production of ozone-depleting substances. By measuring hydrochloric acid levels each fall, scientists were able to gauge the amounts of chlorine in the ozone hole.

New measurements show that the decline in chlorine-resulting from an worldwide ban on manmade chemicals called chlorofluorocarbons (CFCs)-has resulted in about 20 percent less ozone depletion during the Antarctic winter than there was in 2005, the first year measurements were made by NASA's Aura satellite. Chlorine is hard to measure, but when it's run out of ozone to eat, chlorine molecules react with methane to form hydrochloric acid, which is easier to measure. "As far as the ozone hole being gone, we're looking at 2060 or 2080". Mercifully, a recently published study has confirmed positive news after it showed the hole is indeed healing, with new techniques revealing just why that is.

Study's co-author and a fellow atmospheric scientist from the Goddard, Anne Douglass said that, "CFCs have lifetimes from 50 to 100 years, so they linger in the atmosphere for a very long time". "But we're not yet seeing a clear decrease in the size of the ozone hole because that's controlled mainly by temperature after mid-September, which varies a lot from year to year".

This article has been updated with additional information about the NASA study and context about decreasing ozone-depleting substances.



Like this

loading...
loading...

Latest


10 Января 2018
Henry Schein (HSIC) Raised to "Hold" at Zacks Investment Research
State Common Retirement Fund has invested 0.08% in Hexcel Corporation (NYSE:HXL). 89,954 are owned by Aperio Grp Ltd Company. Ohio-based Pub Employees Retirement System Of Ohio has invested 0.01% in Platform Specialty Products Corporation (NYSE:PAH).

10 Января 2018
Microsoft pushes Cortana reference designs, integration potential
At the Consumer Electronics Show on Monday, Qualcomm also announced plans to make Cortana part of its Smart Audio platform . Unveiled last June, the Qualcomm Smart Audio Platform already supports Amazon Alexa and Google voice interfaces.

10 Января 2018
Nicolet Bankshares Inc. Decreases Holdings in Oracle Corporation (ORCL)
Looking at some alternate time periods, the 12 month price index is 1.18248, the 24 month is 1.48431, and the 36 month is 1.41713. Advisor Partners Ltd has invested 0.58% in Oracle Corporation (NYSE:ORCL). 11,283 are owned by Strategic Advisors Limited Co.

10 Января 2018
Oprah for President: Twitter erupts
Ivanka Trump has praised Oprah Winfrey's Golden Globes speech, describing it as "empowering" and "inspiring". Even her longtime partner Stedman Graham was quoted as saying that she would possibly run.

10 Января 2018
CES 2018: Dell PCs To Connect To Smartphones
SMS messages can be engaged with through the Message tab or through an SMS notification as it comes up. It is compatable with iOS 10 and above and Android 5 and above.

10 Января 2018
2017 was 3rd warmest for U.S. , second warmest for Florida
The biggest newsmakers include the western USA wildfires that caused damages tallying $18 billion - triple the previous US record. Thirty-two states, including Alaska, had annual temperatures that ranked in their top-10 warmest.

10 Января 2018
Vikings gift tickets to 99-year-old fan for first playoff game
The Vikings achieved 13 regular-season wins for the second-highest total in franchise history, behind 15 in 1998. When Millie's jaw dropped, family members cheered in the background - more than 30 of them.

10 Января 2018
Susquehanna Bancshares Upgrades The Western Union (WU) to "Neutral"
Analysts are also projecting an Average Revenue Estimate for The Western Union Company as $1.4 Million in the Current Quarter. Duncker Streett Incorporated holds 0.03% of its portfolio in The Western Union Company (NYSE:WU) for 4,450 shares.

10 Января 2018
CSX) — CSX Corporation (NASDAQ
The transportation company reported $0.51 earnings per share for the quarter, meeting analysts' consensus estimates of $0.51. After $0.16 actual EPS reported by ConocoPhillips for the previous quarter, Wall Street now forecasts 150.00% EPS growth.

10 Января 2018
$0.67 EPS Expected for Bristol-Myers Squibb Company (BMY)
The firm owned 2,604,251 shares of the biopharmaceutical company's stock after selling 200,990 shares during the quarter. Vaughan David Investments Inc increased Brinker Intl Inc ( BMY ) stake by 3163.89% reported in 2017Q3 SEC filing.