Scientists are closely monitoring positive signs of recovery of the Earth’s stratospheric ozone layer, which is depleted by the use of chemicals called chlorofluorocarbons (CFCs) for a range of industrial and commercial purposes. Even after the landmark Montreal Protocol banned these substances in the late 1980s, threats to the ozone layer persist. Scientists at NASA’s Goddard Space Flight Center including Susan Strahan and Qing Liang (both NASA/USRA) are weighing in to an ongoing debate about the relative impacts of continuing sources of ozone depletion, including short-lived chemicals not banned by the Protocol, the effects of climate change, and banned chemicals that are still being released into the atmosphere. All could potentially delay the recovery of the seasonal ozone hole over Antarctica. — NASA — Our Changing Earth Source: NASA (https://images.nasa.gov/) Licence: Public domain (work of the U.S. federal government, 17 U.S.C. §105) Audio is served by the publisher; Budi does not host or modify it.
0:00There's a new class of chemical compounds impacting the Earth’s ozone layer and raising concerns among some scientists. But a new NASA analysis indicates stratospheric ozone could actually be impacted more by climate change and the continued release of already banned chemicals. The Earth’s ozone hole is showing signs of recovery, decades after the landmark agreement called the Montreal Protocol that banned many chemical compounds harmful to the ozone layer. So we know the Montreal protocol was a huge success. This was signed in late 1980s when scientists and policy makers from around the world gathered together to try to save the ozone layer The chemicals they regulated persisted in the atmosphere for many decades. They thinned
0:50When the ozone layer and they create a seasonal hole over Antarctica, they basically take away part of our planet's natural sunscreen and that increases the risk of skin cancer and damage to plants. Scientists have projected the ozone hole could disappear almost completely by about 2075 but several factors could delay that recovery. There are some industrial compounds that are not banned by the Montauk Protocol but as they enter the atmosphere, they will also hurt the ozone layers. But the unregulated compounds have a short lifespan in the atmosphere, unlike the chlorofluorocarbons that were originally regulated, so they have a short-lived impact on ozone and we don't think they'll delay recovery by more than a few years.
1:36We projected by 2050, more than half of the ozone depleting compounds in the atmospheric will come from long-lived substances banned by the protocol. Because these compounds stay in the air for such a long time compared to the un-regulated Short-Lived Compounds, they will have a disproportionate and lingering impact on ozone. So any noncompliance with the protocol can have significant consequences. And the really big uncertainty in ozone layer recovery is climate change. There are many naturally produced ozone depleting substances that are emitted by the oceans. And as the oceans continue to warm due to climate change, those emissions will increase and that will further delay ozone recovery.
2:21Scientists want to better understand how climate change will affect ozone recovery. This is a hard problem. As a scientific community, we need to work on this major issue. We now have a powerful new tool to simulate atmosphere and its interaction with land and ocean to study this issue. And that's what we're going to do.
This transcript was generated automatically from the recording, so it will contain mistakes — especially around names and places.