The damaged ozone layer will recover within four decades

When it comes to the Earth’s atmosphere and the environment, it’s been raining bad news lately. But today there are other sounds. After all, things are going in the right direction with our pretty damaged ozone layer!

What do scientists write, collected in the Scientific Assessment Panel for the Montreal Protocol on Substances that Deplete the Ozone Layer in a new report. In their report, they confirm that nearly 99% of the ozone-depleting substances banned in 1989 have been phased out and the ozone layer is recovering as a result. And judging by the rate at which the ozone layer is currently recovering, we should expect it to be fully recovered over Antarctica (where the ozone layer is most damaged) d ‘by 2066. Above the Arctic, the ozone layer should return to normal around 2045. And especially the rest of the world, this could be the case as early as 2040.

The UV radiation
It’s good news. Not just for the ozone layer. But certainly also for us humans. Because the ozone layer protects us from the sun’s harmful ultraviolet rays. And its degradation means more of that harmful UV radiation can reach the surface of the earth (and us). With the reconstitution of the ozone layer, our exposure to this radiation decreases, confirm the researchers.

weather
Moreover, saving the ozone layer has a very pleasant side effect; for example, banning substances that deplete the ozone layer – such as CFCs – also has a very beneficial impact on our climate. For example, researchers recently stated that measures to save the ozone layer, we protect against an additional warming of 2.5 degrees Celsius in 2100. This is partly because ozone-destroying substances, such as CFCs, are also very potent greenhouse gases. Moreover, ozone-destroying substances – if they had not been restricted – would have destroyed the ozone layer much further, so that plants and trees would have been affected by harmful UV rays to such an extent that they would absorb much less CO2 and therefore much more CO2 would remain in the atmosphere, causing the Earth to warm even faster.

Solution
The reconstitution of the ozone layer therefore saves us a lot of misery. But none of this happened on its own; the damage to the ozone layer was caused by man and therefore had to be solved by man as well (see box). And humanity has handled this remarkably well (if we do say so ourselves).

The problems with the ozone layer appeared in 1985. Then researchers discovered the infamous “hole in the ozone layer” above Antarctica. We must not imagine a real “hole”, but a continuous thinning of the ozone layer. The ozone concentration above the South Pole naturally fluctuates: at the end of the Antarctic summer – when the sun reappears – the ozone layer only thins until September, before recovering. But in 1985, researchers discovered that in addition to this seasonal trend, there was another disturbing trend: the ozone layer had been thinner every spring since the 1970s than the spring before. And man was the culprit: we pumped substances into the air that decompose ozone. For the ozone layer to heal, we had to stop doing that. And barely two years after the discovery of the hole in the ozone layer, the Montreal Protocol on Substances that Deplete the Ozone Layer was created for this purpose. Governments around the world have signed this protocol, committing to phase out the production of ozone-depleting substances. Governments put their money in their mouths and from the year 2000 it became clear that this was in fact leading to a replenishment of the ozone layer.

And now we are heading towards a full recovery of the ozone layer. This means that the ozone layer – if we continue on this path – will eventually have the same concentration as in 1980, before the formation of the “hole in the ozone layer”.

Amendment
So that’s thanks to the Montreal Protocol, which was expanded slightly in 2016. That year, governments agreed to phase out the production and use of hydrofluorocarbons (HFCs). Since the 1980s, these HFCs have increasingly been used as a replacement for substances that deplete the ozone layer (which therefore had to be phased out by the Montreal Protocol). They do not affect the ozone layer, but they do contribute to global warming. As a result, it was decided in 2016 to phase out these HFCs as well through an amendment to the Montreal Protocol. And the effects of this are major, say the researchers in their new report. For example, phasing out HFCs by 2100 is expected to prevent an additional warming of 0.3 to 0.5 degrees Celsius.

We can do it
It shows that humanity – if there is the will and the will to put its shoulder to the wheel – can really make deals at the international level to solve a global problem. And that gives some hope for that other global problem that urgently needs a solution: the rapid global warming of our planet. Because if we can agree at the international level to ban certain chemicals, shouldn’t it also be possible to gradually eliminate the use of fossil fuels and thus reduce our emissions and limit global warming?

The Montreal Protocol teaches us that much is possible. But it takes perseverance. For example, it is very important that governments – even now that the recovery of the ozone layer is in full swing – persevere and ignore dying ozone destroyers and hesitate to use ozone depleters not included in the Montreal protocol are included.

geoengineering
Additionally, the researchers in their new report also argue for some restraint when it comes to geoengineering, and in particular the deliberate injection of aerosols into the stratosphere. This approach is sometimes suggested to slow global warming; the aerosols would reflect more sunlight, cooling the Earth’s surface. But, the panel’s research shows that the approach can also have detrimental effects on the ozone layer by affecting the rate at which ozone, which also resides in the stratosphere, is produced and destroyed.

And so we’re not there yet. The ozone layer will take several decades to recover. And even then, caution is in order. But that doesn’t take away from today’s good news. Because the ozone layer is really good again after being badly damaged.