Good news for the ozone layer, but what lessons for climate change?

A few days ago the death was announced of F. Sherwood Rowland, the American scientist who identified the damage being caused by chlorofluorocarbons (CFCs) to the earth’s protective ozone layer. His pioneering scientific work and the fierce campaigning by him and his collaborators led to a UN framework agreement to tackle the problem and to the 1987 Montreal Protocol, which provided the basis for the global phasing out of CFCs and halons in refrigerators, aerosols and industrial processes – a good template, you might think, for global agreement on climate change.

The European Community was of course a major player in negotiating the Montreal Protocol and subsequent decisions.

It all began as scientific theory, but this was borne out by clear evidence, discovery in the mid ’80s of a vast hole in the ozone layer above the Antarctic. The ozone shield which protects Earth from solar radiation was being rapidly eroded, especially during the winter months, potentially exposing people to increased radiation from cancer-causing UV and threatening extensive damage to the natural world. CFCs and related gases were the culprit.

The good news is that the action taken over the last 25 years appears to be working. We have reached a turning point. A recent study suggests that the ozone layer is no longer undergoing the damage that it was. UV radiation levels are beginning to decline and the scale of ozone holes is diminishing. It was always clear that recovery would take many years as the man-made chemicals dispersed, but positive results are now coming through. It just shows how the world can respond when faced with an identified threat. A NASA website illustrates the trend.

The benefits go further: as well as damaging the ozone layer, CFCs and the other targeted chemicals are greenhouse gases which contribute to global warming, so their elimination is already making a contribution to slowing climate change.

What is striking about the CFC measures is how the scientific evidence was accepted by policy-makers and how the world rallied to take action. There were sceptics, and some industrial sectors were opposed to legislation, but the scientific approach – and the precautionary principle –  prevailed. Given the gravity of the threat the world decided it had to act, even if elements of doubt remained. Would that climate change could be approached with the same degree of global agreement and commitment! But it is of course a hugely more complex problem.

There is scientific theory, and then there is experience. Yet again this spring parts of western Europe, including eastern England, France, Germany, northern Italy and Spain are suffering drought, it seems because the jetstream has taken an unseasonal northerly shift, producing a high pressure area across Europe which is blocking access for the usual spring showers from the Atlantic.  Once more there is talk of harvest failure if the rains don’t come soon.

Climate change is just one of the “evil twins”  spawned by CO2 emissions. The other twin, more secretive and silent, is ocean acidification, where man-made carbon dioxide dissolved in the water is already affecting life in the seas and has the potential to damage ocean ecosystems and destroy vital fish stocks. It is surprising that the European Union has paid so little attention to this threat, but a new Swedish study sets out just how serious the risks are.