Is The Ozone Hole Causing Climate Change
One of the earliest climate model predictions of how human-made climate change would affect our planet showed that the Arctic would warm about two to three times more than the global boilerplate. Forty years afterward, this "Arctic amplification" has been observed firsthand.
Record-breaking Arctic warming and the dramatic pass up of sea ice are having severe consequences on sensitive ecosystems in the region.
Just why has the Arctic warmed more than the tropics and the mid-latitudes?
We at present know that this is due, in function, to tiny concentrations of very powerful greenhouse gases — ozone-depleting substances such as chlorofluorocarbons (CFCs).
A wonder gas?
The ozone layer is the protective layer in the stratosphere, roughly 20-50 kilometres above the Earth, that absorbs harmful ultraviolet radiation from the sun. Ozone-depleting substances are potent greenhouse gases, simply they are more than usually known for their devastating effect on the ozone layer.
These chemicals were invented in the 1920s. They were touted as "wonder gases" used equally refrigerants, solvents and propellants, in refrigerators, air conditioners and packing materials. It wasn't until the 1980s when scientists discovered a hole in the ozone layer above Antarctica that they realized the full extent of the ozone-depleting nature of these chemicals.
Baca juga: What are ozone depleting substances?
In 1987, 197 countries agreed to phase out their employ of ozone-depleting substances by ratifying the Montréal Protocol. The success of this historic international agreement has reduced the emissions of CFCs to nearly cypher; however, the recovery of the ozone hole has been slower equally CFCs remain in the atmosphere for decades.
Due to the effect of ozone-depleting substances on the ozone layer, climate scientists who report these chemicals and their climate impacts have been focused on the consequences of ozone depletion. The climate affect of ozone-depleting substances themselves has been typically considered small given the very tiny concentrations of these gases in the temper, and has been largely unexplored.
Experimenting with climate models
My colleagues and I were interested in understanding how ozone-depleting substances might accept influenced belatedly-20th century warming from 1995 to 2005. We specifically chose this time flow in order to capture the rapid ascension in ozone-depleting substances in the atmosphere over this time. Since the early 2000s, atmospheric concentrations have been declining.
One style that climate scientists approach problems similar this one is to use computer models of the Earth to understand what the effects of different phenomena, such equally volcanic eruptions, and greenhouse gases, such equally methyl hydride, might have on air temperatures, ocean circulation patterns, rainfall and so on.
To explore the contribution of ozone-depleting substances to late-20th century warming, we ran a climate model over the flow from 1955 to 2005. One of the simulations incorporated all of the diverse historical climate drivers — those that warm the climate, like carbon dioxide, methane, nitrous oxide and ozone-depleting substances, and those that cool the climate, like volcanic particulate thing. The second simulation had all the historical climate drivers, except the ozone-depleting substances.
This is one of the first times the role of ozone-depleting substances had been isolated. Typically, climate model experiments that examine the roles of dissimilar climate drivers will lump all greenhouses gases together.
Comparing the two model simulations revealed that global warming was reduced past one-3rd and Chill warming past one-half when the ozone-depleting substances were not included in our simulation.
Chill amplification
Why do ozone-depleting substances have such a large impact despite their very small atmospheric concentrations? First, these chemicals are very potent greenhouse gases, a fact that we have known for a long fourth dimension. 2d, in the late-20th century, warming from carbon dioxide is partially cancelled out by the cooling that comes from particulate thing in the atmosphere, allowing CFCs and other ozone-depleting substances to contribute substantially to warming.
Finally, when information technology comes to Arctic amplification, we know that this phenomenon arises from feedbacks inside the climate system that act to raise warming, and this is exactly what we find in our model simulations. In the simulation without ozone-depleting substances, the climate feedbacks were weaker than in the simulation with them, resulting in less Arctic amplification.
Understanding why the feedbacks differ is the aim of our future research but, in the concurrently, our work conspicuously demonstrates the meaning affect of ozone-depleting substances on Arctic climate.
Thirty years ago, those who signed the Montréal Protocol were not thinking near climate change. Yet, research such every bit ours underscores the important office this agreement will play in mitigating futurity warming as the concentrations of ozone-depleting substances decline over time.
That said, without massive reductions in carbon dioxide emissions in the coming decades, the gains we volition achieve through the Montréal Protocol will be chop-chop overwhelmed. Further action is needed to protect the Chill — and our planet.
Source: https://theconversation.com/the-unexpected-link-between-the-ozone-hole-and-arctic-warming-130438
Posted by: taylortheard.blogspot.com
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