It was 104 the other day in Portland and it will likely be just as hot today, so conversations have been turning to the subject of global warming. How soon everyone forgets our much cooler than average spring with temperatures often ten degrees below normal.
There are four questions concerning global warming:
Is it happening?
It is warmer than it was 150 to 200 years ago. We know this from scientific records and observations. The Columbia River actually froze over for a couple of months in the winter of 1846-7. This was, however during the “˜Little Ice Age’, a period of colder temperatures from about 1400 to 1850, with a period of worldwide glacial expansion beginning in 1850. One of the minima, or coldest periods, was centered around 1850. Prior to the “˜Little Ice Age’ the earth underwent a period of warmer temperatures referred to as the “˜Medieval Warm Period.’ The Vikings took advantage of ice-free seas to colonize Greenland and other outlying lands of the far north. It’s worth noting that Greenland was so named because the Vikings found its southern region green and fertile with temperatures suitable for colonization — as opposed to the frozen waste it is today. Although there are no scientific temperature records from the time, we know from historical writings that it was warmer then than it is now.
Did we cause it?
We have about a thousand years of weather observations and what they tell us, in a nutshell, is that for about 500 years it was “˜warmer’ and that for the next 500 years it was “˜colder’ and now it’s getting “˜warmer’ again. It appears that there is some sort of natural climactic rhythm at work here, but are we contributing to a greater than “˜normal’ increase through the emission of “˜greenhouse gasses’? It is impossible to say. We’ve only engaged in the scientific collection of temperature data in the U.S. for a little over a hundred years, about the same in Great Britain, and considerably less (if at all) in most of the rest of the world. Temperature estimates for the past are theoretical reconstructions. We don’t really know how “˜warm’ it was during the “˜Medieval Warm Period’ or how cold it was during the “˜Little Ice Age.’
Can we do anything about it?
The answer to this question depends on to what degree you believe people are causing global warming or if it even exists. If you believe we are entirely or significantly responsible for global warming, and that global warming is a bad thing, then your answer is that we must cease emitting “˜greenhouse gasses’ immediately. This means not just the U.S., but the entire world. Somehow, I don’t think the developing world is going to go for this. That’s the problem with the Kyoto Treaty. It places strict limits on the U.S. and almost none on the developing world including India and China — likely to be the biggest polluters of the 21st century, if they’re not already. If you believe the global warming arguments are bunk, the question is moot – we should quit tying the hands of business and increasing the expense of consumer goods with useless, idiotic emissions standards and regulations.
Should we do anything about it?
The unfortunate truth about global warming is that we’re a lot like a frog sitting in a pot of water on a stove who doesn’t know whether the stove is turned or not. If there is no global warming, we’re OK, but if there is significant, human caused global warming and the predicted disastrous results, we won’t know until we’re already boiled — maybe. Recent research indicates that when the earth gets warmer, ocean currents may change, bringing about cooling. The earth may self regulate. That millennium long heat and cold cycle we just experienced may just be the earth’s equivalent of your home’s climate control system, but we won’t really know for another thousand years.
NOTE: Both these pages refer to a “small number” of scientists who believe that evidence of global warming is inconclusive or nonexistent. There are, in fact many. See the following articles: