Any climate specialist worth their weight will tell you the following:
1. Climate is an exceptionally chaotic thing to study. For those with some basic physics and know that there is some relationship between the distance you travel, the time you travel, and the average speed you travel (which can be modeled nicely in a neat little equation: s = d/t). Climate is the exact opposite of that. Climate models are far from ever nice or neat. Even the most elegant ones aren’t very elegant in comparison to simple phenomena.
2. When it comes to the whole “What is causing global warming?” (and it is happening) …. is it gas guzzling cars or solar activity, or some combination mixed with other things, the best answer is “yes”. Many global warming denialists often say there is little evidence that human factors are influencing the temperature of the planet. This is along the same lines of “there is no evidence denying the existence of leprechauns” … the absence of evidence means nothing …. besides, there is at least some evidence that human influence is playing a role. The exact mixture is what may remain unknown.
The role of global warming is going to potentially be big in the next century. Some low lying land has the possibility of being inundated more easily by a rising sea level, but the more immediate issue is going to be the greater potential for damage from hurricanes, tropical storms, and those rarer tsunamis. Parts of the world where water is scarce will see it a lot more scarce (fortunately this isn’t anywhere unstable like the Middle East … oops, it is!). On top of that, there is some evidence that the Western United States is coming out of an unprecedented wet era, and that it is starting to return to its more natural drier conditions …. that has a big impact on agriculture and the expanding population out west.
But back to the main point. The real cause of global warming is that big start; the sun. The sun is on one level a giant nuclear fusion reactor, but even that is an oversimplification. It is more like a really complex nuclear fusion reactor. Like pre-menopausal women, the sun goes through cycles. Like some women who get unexpectedly pregnant, those cycles aren’t the most regular of cycles!
Sunspots have been observed on the sun as long as we have been able to observe the sun (roughly 400 years or so). Sunspots are dark spots that appear on the surface of the sun and act roughly like poles on a magnet. While these spots themselves are cooler than the surrounding plasma that makes up the sun, its disruption of the flow of said plasma actually has the effect of making the sun give off more energy.
The number of sunspots that appear on the sun are not regular. They exist in a roughly 11 year cycle. At the start of the cycle, the number of spots goes up very quickly, and then for the rest of the 11 years, the number of spots decreases slowly. But like I said, these cycles aren’t all the same. The twentieth century saw a general increase in the number of sunspots in each cycle …. up until about the mid-1960s (global warming denialists rejoice!) … but since then, the number of sunspots in each cycle has seen a decrease (global warming denialists, denied!).
However, there is some evidence that we haven’t seen anything yet! Some scientists believe that we may in fact be heading into a second Maunder Minimum.
Back about 1640 or so … the early days of telescopy, observers started to notice that the number of sunspots was getting downright low! And between 1645 and 1720, the number of sunspots got really, really low ….. like there were hardly any at all. During the first 30 years of the Maunder Minimum, there were a grand total of about 4 dozen sunspots found. Over an average 30 year span, that number is closer to 30 or 40 thousand! It was obvious something was happening. The same thing sort of happened in the early 1800s … it wasn’t as bad, but sunspots were seen at a much lower rate.
So what? So the sun will have fewer blemishes because it has been staying out of the s … never mind!
Remember how I noted that the American West has spent most of the twentieth century recovering from record moisture and fertility? That was because of the weather on Earth for about 200 years between the 16th and 18th century … the global temperatures dropped fairly noticeably … so much so that historians, agriculturalists, and climatologist call that era of history “The Little Ice Age”.
Now, it really could be coincidence (it could be), but the Maunder Minimum was practically smack dab in the middle of that time.
Here is the good news: if we are heading into some kind of minimum of sunspot activity, we could see some reduction in the effects of global warming …. that doesn’t mean we should give up trying to repair the environment …. that means we should than our lucky stars that mother nature is allowing us to purchase the one thing we normally can’t buy: time.
Here’s the not so good news. The Maunder Minimum happened in the middle of that cooling. That means, the Little Ice Age had already started by the time the Maunder Minimum started. Since we are clearly not in the middle of any global cooling event, we may not be seeing too much of an effect on the environment at all.
The fact is, even though science has been around in some good form for about 450-500 years, the technology to see a lot of things has only been around for maybe 50-100 years … that means a lot of things that are affecting the Earth are only be ing measured and charted for the first time. I know that this makes a lot of the public lose faith in what science can do. But people gotta understand that as important as understanding the Earth’s climate is: it is going to take time, and it is going to take a lot of good thinkers. People need to know to take anything in the press, especially things related to science with a grain of salt. Give the scientists the time they need to do their job.
edit: shame on me for not giving credit where credit is due … while I had seen this come across my desk during our daily lunch discussions at work just before the school year ended, and I had meant to blog on it, I was reminded of this by my good friend, Tom. His blog has a number of always very cool things to think about (not the least of which are the pictures of two really, really cute kids).