Ozone layer recovering, slowly
The ozone hole over the south pole, as seen by satellite on October 15, 2005. The blue and purple colors are where there is the least ozone, and the yellows and reds are where there is the most. Visit NASA's Ozone Hole Watch to see updated satellite images of the ozone hole. Click to expand.
DB: This is Earth & Sky. Earth’s protective ozone layer seems to have stabilized and might be on a long road to recovery.
JB: That?s according to Betsy Weatherhead of the University of Colorado in Boulder. She and a colleague reviewed satellite data and found that, over the past decade, the ozone layer stopped thinning and in some places appears to be growing. They attribute the turn-around to the 1987 Montreal Protocol, an international treaty that banned ozone-destroying chemicals.
Betsy Weatherhead: I’m absolutely impressed not so much as a scientist, but I’m just impressed as a citizen of the Earth. This was a global problem. It was a real threat to the environment and as a result of the collaboration between scientists, policy makers, chemical manufacturers and even everyday citizens, we ended up arresting the problem and we’re starting to see the Earth as a whole improve.
DB: Experts believe it could take 50 more years – at least – for the ozone layer to recover completely. Meanwhile, said Weatherhead – because of the increased risks of skin cancer and cataracts – people should still limit their exposure to UV radiation by wearing hats, sunglasses and sunscreen.
Betsy Weatherhead: No one should be thinking, “Great, I can throw out that sunscreen, I never liked it to begin with.” No one should interpret these results that way.
_JB: Our thanks today to NASA explore, discover, understand. We’re Block and Byrd for Earth & Sky.
Our thanks to:
Betsy Weatherhead
Atmospheric Scientist
NOAA’s Earth System Research Laboratory
Boulder, Colorado
Mark Jacobson
Environmental Fluid Mechanics and Hydrology
Department of Civil and Environmental Engineering
Terman Engineering Center
Stanford University
Additional Teacher Resources
EPA: Ozone Science: The Facts Behind the Phaseout
The Earths ozone layer protects all life from the harmful radiation from the sun, but human activities have damaged this shield. Less protection from ultraviolet light will, over time, lead to higher skin cancer and cataract rates and crop damage. The U.S., in cooperation with over 160 other countries, is phasing out the production of ozone-depleting substances in an effort to safeguard the ozone layer.
NASA: Good News and a Puzzle
Think of the ozone layer as Earths sunglasses, protecting life on the surface from the harmful glare of the strongest ultraviolet rays of the sun, which can cause skin cancer and other maladies.
