Global warming -- real climate change, or just hot air?

[The first of a series on environmental politics.  Because it was written almost five years ago, perhaps a little updated commentary is in order.  Recently, the news media have been giving extensive coverage to issues of global climate.  On a daily basis, we hear dire predictions of huge rises in sea level, phenomenal increases in the number of hurricanes occurring every year, and droughts of Biblical proportions.  Al Gore gets the rock-star treatment wherever he goes – including an appearance before Congress.

As regular readers know, I have a degree in environmental science – and far be it from me to show a lack of concern for the Earth and its future.  However, the current alarmist political climate, and its attendant distortions of what atmospheric scientists are actually saying, does little service to the Earth, or to the “truth,” notwithstanding the use of that word in the title of Gore’s Oscar-winning film.  The IPCC’s Fourth Assessment Report has not yet been officially released – but according to the information that has been made available in advance of the report itself, the picture is nothing like what Gore portrayed on the screen.  Although the IPCC’s scientists have a better idea of what’s going on with the Earth’s climate – and have raised their figure for likelihood of human involvement, to the 66-90% range – their actual predictions for the next century are decidedly non-Apocalyptic.  For example, even taking the report as Gospel Truth, we can expect a rise in sea level of only 17-35 inches – hardly enough to flood coastal cities and swamp south Florida.  What’s more, any changes will be gradual – as they have in the past (where they’ve been so gradual, we’re not even sure they’ve occurred at all).

So despite what you hear on NPR, CNN, and Imus in the Morning, global warming is not a sure thing.  It is likely – not certain, but likely – that anthropogenic carbon dioxide is affecting the Earth’s climate; and it is likely that global average temperature has risen slightly as a result.  But the scientific “consensus” is not nearly as monolithic as the frenzied media would have us believe.  They haven’t read the IPCC reports – just the politically-charged executive summaries.  I recommend delving into the actual reports, which are free on the IPCC’s Web site.  The actual reports give a much more nuanced picture than what you get from Al Gore and Friends.

In any case, I stand by the assertions made in this column. Not much has changed in the past five years, except for the level of hysteria… ed.]

FLAGSTAFF, Arizona, May 19, 2002 -- Environmental issues are probably the biggest political hot potato we've got these days, at least in terms of domestic issues. As a card-carrying member of The Nature Conservancy -- and one with a degree in environmental science -- I like to think I'm as concerned about the Earth as the next person. But the environmental movement has become politicized in recent years, to the point where it's more about ideology than science.

The problem is that what's "obvious" often isn't true.

On issue after issue, it seems obvious, on the surface, that there is a "crisis" occurring and that the fate of the Earth (or a part of it) depends upon our following a certain course of action that the environmental groups have decided is necessary. And anyone who doesn't see that the sky is falling is clearly an apologist for oil companies, developers, or other moneyed interests.

Well, the problem is that what's "obvious" often isn't true. When you get on the ground and look at the actual scientific data, they don't always point to a clear crisis or suggest a particular course of action.

This series will discuss three cases in point: "global warming" and climate change; the U.S. Forest Service's Roadless Initiative; and the Colorado River and its capacity for supplying the southwestern U.S. with water. Briefly, I'll argue that (a) the Earth's climate is probably not warming up, at least not due to human activity; (b) no useful purpose is served by closing Forest Service roads and trails; and (c) the Colorado is perfectly capable of supplying water to a lot more people than it does at present and that it's just a matter of buying water rights from the farmers (not cities -- surprise!) who currently use most of the water.

How warm is it?

I recently attended a lecture by Tasmanian climate researcher John L. Daly, who is the author of a number of articles that poke holes in the widely-accepted idea that the Earth is about to blow a gasket because of human-caused climate change.

One hot summer means nothing, in terms of showing which way the Earth's climate is headed.

In 1988, we had a really hot summer. Driving a car without air conditioning, I sweltered through rush-hour commutes, day after day, as I think the Greater Boston area hit 90 degrees or better every day during August. If memory serves, the lower Midwest and Southwest, especially Texas, experienced a blistering drought that year.

Well, we did have a hot summer. But -- as any climatologist will tell you -- that's only one data point. It means essentially nothing, in terms of showing which way the Earth's climate is headed.

Climate change takes hundreds (or thousands) of years. For us, with lives spanning only a few decades, it's hard to see the forest for the trees.

Nonetheless, we started hearing from environmental activists who had decided that the hot summer constituted "global warming." Further, they asserted, this warming was caused by human activity -- in particular, the burning of fossil fuels, which releases large amounts of carbon dioxide, which has altered the Earth's climate in ways that can only be disastrous. The logical extension of this was that immediate action was required, to cut down our consumption of fossil fuels and the associated carbon buildup in the atmosphere.

That's a lot of conclusion, from one data point. The problem is that climate change is the product of a complex set of variables, which interact with each other over long periods of time. It takes thousands of years for the Earth to heat up to its historical maximum mean temperature, and thousands more for it to retreat to its minimum. For us humans, with lives spanning only a few decades, it's hard to see the forest for the trees.

We've continued to have warm years since then. Some dry ones, too. As I type this, Arizona has just experienced one of the driest winters on record -- which is saying something, for out here. But we're still just looking at trees. If we start looking at the forest, it becomes apparent that what we're going through now is hardly a warming of historic proportions -- or even, necessarily, a warming at all.

Nothing new under the sun

Consider the conditions that prevailed from roughly 1000-1300 A.D., a span of years known to climatologists as the Medieval Warm Period. During this time, global temperatures were higher than they'd been in a long time -- and, to the extent we can determine, probably considerably warmer than those prevailing today. The most oft-cited result of this was that the population of Greenland -- now covered by thousands of feet of ice -- was much higher than it is today, and that one of the principal ways people survived there was by farming.

When you look at real temperature data for the 20th century as a whole, there isn't much evidence that the Earth's climate has warmed more than about one degree Fahrenheit.

John Daly points out that in all likelihood, both the Medieval Warm Period and the Little Ice Age that followed (most notably between the 16th and 19th centuries, during which time the river Thames used to freeze over regularly in winter, as is amply documented in contemporary accounts of English life) were accompanied by significant variations in solar output.

We don't have a lot of sunspot records from the earlier period, but we do have good records for the period of the Little Ice Age -- you can make a sunspot map by projecting the sun's image onto a piece of paper with a small telescope and tracing what you see, and many astronomers did just that. Sunspots are a reliable indicator of solar output, and as Daly argues, the sun's output was considerably lower during the Little Ice Age than it has been during the past 150 years or so (coincidentally, the industrial age -- leading people to conclude that human industrial activity caused the warmup). Although we don't have sunspot records for the Medieval Warm Period, we certainly have historical proof that the warming occurred -- people really were farming Greenland during that time.

As for the 20th century, when you look at real temperature data for the whole century, there really isn't much evidence that the climate is warming at all.

A study of glacial ice published by the American Geophysical Union (AGU), available on their Web site, notes that, "Examination of a 217-meter temperature profile ... reveals a recent warming in near-surface firn [a type of ice] which is within the range of natural variability, providing no definitive evidence of anthropogenically-induced greenhouse gas warming [Alley and Koci, 1990]."

At the same time,however, the AGU's "Science and Society" journal notes, in an article from 1999, that the general public has become convinced that global warming is a serious problem:

There is... a great deal of agreement about the importance of global warming. Gallup found that many people feel that in the next 25 years, global warming will have a very or somewhat harmful effect on things such as agricultural production (74%), the survival of many animal and plant species (73%), and even on human health itself (72%). Many of our respondents said that global warming and the factors that cause global warming are also associated with health problems, especially cancer. While only 28% think that global warming has had a serious impact already, 51% think it will have a serious impact in the future.

The cause of this misperception? Bad science (and, more recently, political hysteria on the part of environmental activist groups). Daly's lecture pointed to many flaws in the climatic models that purport to show that the Earth's climate is changing -- in particular, warming -- at an alarming rate. He illustrates that most of the studies used to support claims of catastrophic global warming make very selective use of data; they pick specific time periods and locations that appear to show a lot of warming, while if you look at global data over a long period of time, the apparent warming trend disappears.

There's a lot of research out there, and making a comprehensive case against global warming is beyond the scope of this column. But take a look at some of the literature yourself; besides Daly's site and that of the AGU, another excellent source is the Center for the Study of Carbon Dioxide and Global Change. There are many others out there as well. The important points to keep in mind are that (a) the Earth's climate varies greatly, over long periods of time, (b) there's amply documented evidence that significant change has occurred within relatively recent times, and that (c) the changes are adequately explained by natural phenomena.

Bad science is worse than no science

None of the above is to argue that cutting down on our fossil-fuel consumption wouldn't be a certifiably good thing. There are many reasons why it would be good -- smog stinks, there's only a limited amount of oil in the ground (and we have to go further afield to get it these days, including politically-sensitive areas like the Caspian Sea and environmentally-sensitive areas like the arctic), and good environmental stewardship dictates that we shouldn't waste natural resources. But the hysterical environmental groups who treat global warming as fact and shout down anyone who questions their dogma do nothing to foster understanding of what's really going on.

The problem with the global-warming alarmists is that they assume their conclusion: that the Earth is warming up. They look at the thermometer, see record-high temperatures (keep in mind, of course, that we've only got reliable temperature records going back a century or so -- the blink of an eye, in climatological terms -- so a "record high" just means the highest temperature recorded since we last blinked), and decide that we've got a crisis on our hands. Then, they go out and look for data that support this conclusion they've assumed -- throwing out all the data points that don't support it.

It's time we had more respect for science. Collect the data first, then draw the conclusions. In the case of global warming, the data just don't support the conclusion that the Earth's climate is changing in any significant way. The Science & Environmental Policy Project, which circulated a petition against the 1997 Kyoto Protocol, collected the signatures of 17,000 scientists to dispute the conventional wisdom on global warming. Now, I'm certainly not going to argue that the number of signatures, in and of itself, means much -- but what it does suggest is that global warming is not scientific Truth, even if it has become political Truth.

Show me the money!

When presented with the inconclusive evidence of climate change, Daly says, environmental groups invariably brand him a "puppet of the oil industry," or some such nonsense. "If I'm supported by the oil companies, it's news to me -- I'm still waiting for the checks to appear in my mailbox," he quips.

What it amounts to is that the global-warming Chicken Littles can't stomach the fact that the anecdotal evidence we've been seeing -- a few hot summers, starting in 1988 -- does not constitute a global climatological phenomenon. I'm sure their intentions are good -- and I'm all in favor of saving the environment, just as they are. But running around chasing the latest apparent "crisis" is not the way to go about it. Before we can fix a problem, we need to know that we have one -- and with global warming, the picture is far from clear.

[Next: The U.S. Forest Service, the Clinton-Gore Roadless Initiative, and the decline of public access to public lands.]

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