Global Warming for the Skeptical

Alpine flowers---earlier every year.

Alpine flowers—earlier every year.

I saw some hyperbole on a website the other day, warning of sea level rises of 35 meters by the end of the century, due to global warming. I’m not so sure. But, that’s not to say that I think that the planet isn’t warming, because I’m even more unsure about the claims from the other extreme that nothing is happening, or that, if it is, humans don’t have anything to do with it. The truth is somewhere in the middle here—the planet is clearly warming, and human activity is nearly certain to be a major cause.

But while I do have an opinion, I’ve got plenty of friends, relatives, and acquaintances that are confused, misinformed, or misguided about the issue, and often end up not knowing what to think. It’s easy to see why—vested interests have purposely obfuscated the issue, political elements have ignored or ridiculed inconvenient data, and statistics have been used incorrectly by all sides. Worse, the warnings of a few degrees of warming, set to occur over decades, often don’t strike fear into people’s hearts. My post about Mr. X’s devil’s-advocate views (“Mr. X on Global Warming“) sums up the more rational side of this position.

BUT, I think common sense can help us out here. Leaving the graphs and trend lines and statistical margins of error aside, there are quite a few changes in the world that are clear to see and aren’t in doubt, and when taken together shed light on this issue. In no particular order–

— Glaciers are in retreat the world over, at rates that are astounding the scientists that study them. Photography provides clear proof of this. Some images from the US Geological Survey–

Grinnell Glacier USGS cropped

Sperry Glacier USGS cropped

Identical changes are occurring worldwide; many more images can be found at USGS and elsewhere on the web, such as the National Snow and Ice Data Center. And it isn’t some tiny fluke, the melting of glaciers is massive and ongoing.

— Arctic sea ice is melting. Despite the flap the other month instigated by a skewed report in the U.K. by David Rose, the Arctic is melting (see post “Et Tu, Time?”). Many reputable groups expect the Arctic to be nearly ice-free in summer by mid-century, and nations around the polar circle are scrambling to position themselves to take advantage of new oil exploration and shipping opportunities. Articles such as this one from Business Insider, “China Begins Using Arctic Shipping Route that ‘Could Change the Face of World Trade’” are easy to find. It isn’t just number and graphs—it’s reality above the Arctic Circle. Reports that polar bears, notoriously good swimmers, are drowning for lack of sea ice aren’t being fabricated out of thin air.

— Sea levels are rising, the oceans are getting more acidic and warmer, and reefs are dying. It’s occurring to me that this could end up being a very long post if I’m not careful, so I’ll shorten up my explanations. But, none of these things are really in doubt, and information about the topics abounds. Two really good articles about these ocean topics are worth mentioning, though, one on ocean acidification recently in The Economist, “Acid Test: The world’s oceans are becoming more acidic. How much that matters is not yet clear. But it might matter a lot.”, and the cover story in National Geographic in September, “Rising Seas“. Needless to say, carbon dioxide and climate warming are at the root off all four of these ocean problems.

— In North America, days of snow cover are down, spring arrives earlier, and frost occurs later, in trends that go back decades. This effect is large enough that the USDA has reworked their plant hardiness zone maps in ways that reflect about a 5-degree Fahrenheit increase in temperature. (One article of many, this one from the Washington Post, “New USDA Plant Zones Clearly Show Climate Change“). Changes in average snow cover have been extreme enough that they have prompted Porter Fox, an author at Powder Magazine, to write “DEEP: The Story of Skiing and the Future of Snow”. A portion of a review from Outside Magazine–

Deep book cover
“The snowpack in British Columbia has declined by half overall and the ski season in some regions is four to five months shorter than it was 50 years ago,” he writes in DEEP.  “Eastern Canada is even warmer… Computer models show the Northeast ski season shrinking to less than 100 days by 2039. Under other models, the mean snow depth for the Rocky Mountains is predicted to drop to zero by 2100.”

This summer at Solarfest I heard a similar presentation by Dr. Alan Betts of Atmospheric Research in Vermont, where he gave an hour-long presentation, with photographs, of an extremely long list of frost dates and snow cover and plant blooming times, all of which provide near-unmistakable evidence of warming in New England.

The USDA 1990 map---a colder U.S.

The USDA 1990 map—a colder U.S.

 — The Snowshoe Hare, the Canada Lynx, and trees in the Rockies have been clearly impacted by a warmer planet. Just to start with the trees, the headlines are pretty self-explanatory— “Study: US Trees Dying at Alarming Rate” (Time), “How the Pine Beetle is Destoying Colorado Forests” (Newsweek), “What’s Killing the Aspen” (Smithsonian), “What’s Killing the Great Forests of the American West?” (Yale.edu)… The root of the problem—a warmer climate, which stresses trees and allows insect populations to mushroom to previously unheard-of levels.

Canada Lynx.

Canada Lynx.

Related is a huge shift in the populations of the Canada Lynx, pushed out of thousands of square miles of range due to reduced snowfall levels and the unfortunate demise of many of its primary prey, the snowshoe hare, itself a victim of often being the wrong color in a changing world. (One article of many—“Canada Lynx and Climate Change: Rising Temperature and Declining Snow Fall Spell Trouble for Canada Lynx.”). None of this is exclusive to the US—similar situations can be found worldwide.

I could go on, but I suppose my main point is this—you don’t have to be a scientist in some esoteric field to see that the earth is getting warmer—evidence abounds. Now, some would argue that yes, the world is warming, but that human activity isn’t a factor. This argument seems equally untenable; the science behind how greenhouse gasses work has been understood for a century, and the rise in CO2 has almost exactly mirrored both warming and human industrial development (post, “A Matter of Limits“). In 2012 the world emitted 30,000 million tons of CO2, and we’ve been emitting similar amounts every year for decades. You just don’t have to be a rocket scientist to put two and two together here.

The problem, or one of the problems, is that all of this change, while extremely rapid on a geologic scale, seems to be occurring just slowly enough to be beyond the natural human threshold for arousing fear and alarm. We’re like the proverbial frogs in the boiling pot—the water’s getting hotter, but we aren’t jumping out. (Interesting Psychology Today article—“Climate Change: A Psychological Problem“).

Now, don’t get me wrong. As I’ve said before, I would like nothing more than for future data to show that we were all wrong about human-induced climate change, it would be a huge blessing for mankind. I’m not some zealot in a new secular religion of climate alarm, proselytizing to the unfaithful. But, reason and common sense militate against the idea that nothing is happening, or that humans are uninvolved. So, don’t be confused, and don’t let this or that extremist keep you from seeing the forest for the trees. It is a near-certainty that the planet is warming, that humans are causing it, that the change is rapid in the broad view of things, and that it’s a dangerous path for all of nature, which ultimately includes we humans.

29 Jan 2013: A link to a 15-second NASA video that is an excellent visual representation of all this.

 Top image credit: “Flowers on the Edge”, by Bryant Olsen, Creative Commons, at http://www.flickr.com/photos/22837563. Image has been cropped.
Grinnell and Sperry Glaciers– USGS Repeat Project, photographers listed in graphics.
1990 Hardiness map– USDA.
Lynx photo– USFWS.