We have caused a lot of damage to nature, but there are things we have managed to fix - almost

There is no easy cure for problems like climate change because they are caused by complex, overlapping challenges that can only be tackled carefully, if at all. But there have been times in the history of humanity when we managed to fix past mistakes caused by our own actions.

Who can remember acid rain? One of the most threatening phenomena associated with pollution in the 1970s, 1980s and 1990s was so-called acid rain, toxic precipitation that contained high levels of sulphur dioxide. Fish disappeared from the rivers of Scandinavia, the forests and lakes of North America became depopulated forever - or so we believed.

"In the '80s, essentially the message was that this was the largest environmental problem of all time," says Peringe Grennfelt, a scientist at the Swedish Environmental Research Institute (IVL) to the BBC. The British public media explored in a lengthy analysis what we did well at the time of the former dangers and what we can learn from them when it comes to tackling climate change.

The first lesson is perhaps to discuss problems a lot: in the 1980s, headlines warning of the threats of acid rain were commonplace, keeping the topic on the agenda, which led to a series of international agreements. In these, countries around the world pledged to reduce their sulphur dioxide emissions through regulations. The result is that Acid rain is now largely a thing of the past in Europe and North America, although it remains a problem elsewhere, particularly in Asia. In any case, this is a good example of how international cooperation can help to overcome obstacles that seem insurmountable at first.

The actions related to leaded fuel was similarly successful. With the proliferation of combustion engines, it become important that they should not rattle or damage themselves; the solution was more efficient combustion, which is why manufacturers mixed lead with the fuel. Although alcohol could have done the job just as well, it would have pushed fuel prices up, from the 1920s onwards, adding lead became a standard procedure. Leaded petrol releases lead particles into vehicle exhausts, (and for that matter, into our lungs). Although it took a long time, international pressure became so strong in the 1980s that most countries banned lead. Moreover, over time, unleaded petrol has become cheaper than leaded, which was nevertheless still used in developing countries until 2012 - the last country to ban it was Algeria. Of course, the lead emitted in the past will still be in the environment for a long time to come.

Furthermore, the problem of the hole in the ozone layer was also talked about a lot in the 1980s and 1990s. Our planet is protected from harmful space rays by ozone molecules made up of three oxygen atoms. But old aerosols and refrigerants emitted gases that neutralised the ozone layer, and in 1985, the British Antarctic Survey (BAS) alerted the world, saying that if it were to go on like this, our Earth would be vulnerable to harmful particles.

Two years later, in 1987, world leaders signed the landmark Montreal Protocol, hailed as one of the most successful environmental treaties of all time, as it is the only UN agreement signed by all 198 countries of the world. The Protocol governing the production and release of nearly 100 chemicals brought results; the ozone hole began to shrink. Of course, it did not disappear completely, sometimes it even increases; it was 24.8 million square kilometres in 2020 (the record was 29.9 million square kilometres in 2000). There are several reasons for this: on the one hand, some of the substances that replace regulated gases were later found to be harmful, so these also had to be regulated. On the other hand, these substances remain in the air for a long time. “Healing” is a long process.

In any case, international cooperation is clearly crucial, it can help to tackle even complex issues such as climate change. It is important to talk about this, to keep it on the agenda, to dispel doubts and to find alternatives that can be introduced relatively quickly to balance off the processes that caused the problem, such as fossil fuels.

Of course, we need to be careful with drastic solutions. As discussed in one of our past articles, sometimes measures introduced with the best intention can cause huge ecological damage.

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