Wednesday, May 4, 2011

How about some of that global warming for a change?

Statistics always fascinate me. Occasionally to pass the time, I might do some doodling during the course of which I might actually learn something that I didn’t know before. For example, I couldn’t help but observe that this past April was particularly cool at the airport. There was only one, maybe two days that could be described as “sunny.” The rest were merely miserable. But just how miserable? Using the data from NOAA and the National Weather Service compiled by the University of Washington’s Department of Atmospheric Sciences, I discovered that there was 73 percent more rain than normal for the month (compared to 68 percent above normal for March). But what about temperatures? By adding (or subtracting) the differential between the “normal” and actual daily high temperatures, the average high temperature for April, 2011 was just a shade under 6 degrees below normal, which is rather significant; you can tell just by looking at Mount Rainier, which from this distance appears to be entirely smothered in white. Only one day in April was at or above the normal high temperature, and only five other days were within 3 degrees of normal; the average high temperature of 52.2 degrees was the lowest recorded in Seattle since such records began. The average low temperature for April was 2.6 degrees below normal; the difference between the high and low differentials can be explained by the fact that while the lack of clear skies during the day tends to keep temperatures lower than they might otherwise be, but at night cloud cover keeps whatever warmth that was generated during the day from escaping too rapidly. The overall temperatures in April was slightly over four degrees below normal.

El Nina will be blamed for this, but then again it was predicted that this phenomena would bring Puget Sound a much harsher winter than we actually had; except for a few days in mid-November and late-February, there was no snow. It also couldn’t explain the weather of last May, which was nearly 4 degrees below normal highs. There are two varieties of climate change—gradual and abrupt. The abrupt changes are more obvious—such as what we experienced in April in the Puget Sound area. Why there are abrupt changes has something to do with the Earth system being pushed into a different state by a combination of “forcings” which could include changes in the ocean, atmosphere, land, cryosphere (land covered by ice), as well as the Earth’s orbit and solar events; man-made effects, of course, are also blamed. However, scientists have been unable to accurately predict when these abrupt changes will occur or by how much—which also prevents accurate forecasts for effects on agricultural and water resources; abrupt changes in weather are also trickier to plan for than the gradual change, since it doesn't allow us the convenience of "time."

Nevertheless, the National Research Council states that it is not wise—as the Republicans and conservative scientists would suggest—to simply do nothing:

“It is important not to be fatalistic about the threats posed by abrupt climate change. Societies have faced both gradual and abrupt climate change for thousands of years and have learned to adapt through various mechanisms, such as moving indoors, developing irrigation for crops, and migrating away from inhospitable regions. Nevertheless, because climate change will likely continue in the coming decades, denying the likelihood or downplaying the relevance of past abrupt events could be costly. Increased knowledge is the best way to improve the effectiveness of response; research into the causes, patterns, and likelihood of abrupt climate change can help reduce vulnerabilities and increase our ability to adapt.”

For most people, wearing an overcoat instead of a windbreaker is sufficient to overcome the affects of unusual weather changes. But changes are not always so simple to adapt to. Across America, only 6 percent of spring wheat planting—from a normal of 39 percent—has been planted at this time of year as of last week, due to cool temperatures and excessive rainfall, which prevents fields from drying out enough to begin planting. This may not have obvious affects now, but weather of this sort continuing into the summer or for a number of years could have consequences on the food supply that simply ignoring the climate problem will not solve. Another consideration is that we might be on the cusp of a “Little Ice Age.” The last ice age of this sort occurred from 1550 to 1850, characterized by colder winters and cool, wet springs and summers. This may be just an anomaly; we wouldn’t know for another century or two if we are really in a cooling, rather warming period. At any rate, it is fascinating to speculate—especially if you don’t like cold, wet weather all the time.

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