Sunglasses on your nose, an ice cold drink in your hand, the green grass tickling your bare feet while you breathe in the scent of freshly applied sunscreen: it’s summer! Who doesn’t have fond memories of an endless summer evening in the park, the warmth of the sun’s rays on your skin and that rosy feeling after a day at the beach?
But the smell of fresh sunscreen is not only good for bringing back wonderful summer memories, it also protects you from the ultraviolet (UV) part of the sunlight. It’s not just sunscreen that does this; the ozone layer also protects you against this radiation and prevents you from having to spend the evening lying in the bed you made, covered in blisters.
The Earth’s protective layer
The ozone layer is located at an altitude of 15 to 50 kilometers above the Earth’s surface. It blocks a large proportion of the harmful UV radiation that comes from sunlight, protecting people, animals and plants. Now I can imagine you thinking: ‘the ozone layer… wasn’t there a hole in it?’ Indeed there was: in the 1980s, scientists discovered that the ozone present in the ozone layer was slowly being degraded by the extensive use of artificial substances. The best known of these were CFCs (chlorofluorocarbons), which were frequently used in aerosols, refrigerators and air conditioners, among other things. The result was a gaping hole about 29.9 million square kilometers above the South Pole, which meant more UV light was reaching Earth.
With a hole like that in the ozone layer, more of the sun’s UV radiation reaches the earth. And because UV rays can penetrate deep into our skin, they damage the deeper layers of the skin, causing sunburn or even skin cancer. Increased UV radiation also damages plant cells, causing photosynthesis and plant growth to decline and harvests to fail. So there are good reasons why ‘stratospheric ozone depletion’ is one of the nine planetary boundaries!
Shuffling the alphabet: from CFCs to HFCs
Time for action, says RIVM researcher Guus Velders on our podcast ‘On a date with the planet’ (Op date met de planeet, in Dutch). In 1987, the Montreal Protocol was drawn up in successful collaboration between politicians, industry and scientists. With this protocol, worldwide agreements were made to reduce the amount of CFCs and other substances that damage the ozone layer. From 2000, western countries were no longer allowed to use CFCs, and since 2010 they have been banned worldwide.
These efforts have been successful: Since 2000, the depletion of ozone in the ozone layer has stabilized! Scientists agree, if we hadn’t saved the ozone layer, global temperatures would have risen by another 2.5˚C by the end of the century, and we would have had a much bigger climate problem. But, Velders emphasizes, we have to see the ozone layer as a recovering patient. It’s moving in the right direction, but we have to keep a close eye on it.
A big reason for the success of the CFC elimination effort was the available alternative: hydrofluorocarbons, or HFCs. Since HFCs were much more ozone-friendly than their predecessors CFCs, they replaced CFCs in many refrigerators and air conditioners. However, as Velders discovered, HFCs are very harmful greenhouse gases – 15,000 times stronger than CO2. Paradoxically, this meant our search for cooling with air conditioning and refrigerators caused further global warming! Velder’s insights led to a tightening of the Montreal Protocol, which now sets out agreements on the ozone layer and regulates the use of HFCs.
What can you do?
Be part of a beautiful and hopeful success story! With global cooperation and suitable alternatives, we can protect our planetary boundaries – including the ozone layer. And on 16 September every year, the International Day for the Preservation of the Ozone Layer gives us the chance to commemorate the international agreements that are in place to protect our protective layer.
In addition to global agreements, there are smaller actions you can take to prevent more CFCs and HFCs from being released into the environment. Here are the three most important ones:
- Summers are getting warmer, so it’s understandable that you want to cool your home. It’s interesting to look at alternatives to refrigeration that do not use refrigerants. These six tips will help you cool your home sustainably.
- Do you really need to use an air conditioner? If you do, choose one with a refrigerant that has the lowest possible climate impact. It is mandatory for new mobile air conditioners to use natural refrigerants, which have a low climate impact. Here you can read more about refrigerants and the options you have.
- It’s better not to sell, give away or recycle an old refrigerator, freezer or air conditioner, because it is better for the environment if it’s no longer used. If you have old refrigeration devices at home, don’t just leave them out on the street for collection; instead, have them disassembled by professional processors, by handing them in at the store or to a bulky waste service. This video (in Dutch) shows how the process works.