I’ve been surprised to discover that the controversy among scientists isn’t whether global warming is happening. There is just about universal agreement across the board that it is. For example, the sea level around New York, for instance, is a foot higher than it was 100 years ago, which is one of the reasons why the storm Sandy was so devastating. And a recent report bringing together what up to now had been disparate measures of the polar caps show that ice is melting three times faster than it was just 20 years ago. Some scientists now think that temperatures could increase by as much as 6 degrees Celsius instead of their 4 degrees maximum expectation last year.
The real controversy isn’t whether changes are occurring. The controversy is the cause of this environmental change.
Is it, as some climatologists think, a natural variation around the norm that occurs in the weather over the years? We have, after all, experienced severe droughts before. Floods are not a new phenomenon, nor are mega-storms, or occasionally exceptionally hot summers or warm winter temperatures. Europe even experienced a “little ice age” as recently as the 17th century.
Or is human activity responsible for the increase in greenhouse gases that are changing our weather? Before the industrial age began two centuries ago, greenhouse gas equaled 278 particles/million. Since then, greenhouse gases in the atmosphere have increased by 40% to 391 particles/million. This is the highest it’s been in more than 15 million years.
Again, no serious climatologist claims that greenhouse gases do not contribute to global warming. But some scientists think that we do not have enough long-term data to jump to dooms-day conclusions. They claim, quite rightly, that cutting down on greenhouse gases by using less fossil fuels and more renewable sources of energy may very well slow down the global economy, leading to increased poverty for millions and the deprivations that go with it. Better they say, to wait and see.
Wait-and-see is a recipe for disaster for the majority of climatologists who think the data already is increasingly pointing to human activity as the cause of global warming and destructive environmental changes in Earth’s oceans and on land. They point out that once the data is unequivocal enough to convince even the most skeptical, it will be too late. The melting of the Arctic ice cap is already accelerating; in twenty years time we will not be able to slow the process even if we don’t add another particle of greenhouse gases to the atmosphere.
So this is the question: should we act now even when there is still some modicum of doubt in order to try to avert what might be environmental changes that all agree would be catastrophic for life as we know it? Is it worth the mega-effort and expense that reducing our fossil fuel use will demand? Or should we be careful, keep watching, and trust that should things get worse, we will be able to figure out how to handle it intelligently when it happens?
To some extent, we are in the difficult position of having to answer the question – even by the default option of doing nothing – before we have all the information. But what we decide will have huge implications for our children and our grandchildren. Even if we don’t know for sure what those implications are.