Wednesday, July 29, 2009

It Isn't Hot Here, No Siree...

Image credit: Screenshot of NWS forecast by Cujo359

No, it isn't unusually hot out here in the Pacific Northwest today:

[W]ill a record be broken today or not?

The all-time high temperature of 100 degrees in Seattle was set July 20, 1994.

Official temperature records have been kept locally since 1894, and back then official temperatures were taken at the Federal Building in downtown Seattle.

So it's been 115 years of not one single 100-plus-degree day.

Heat Wave Puts High Pressure On Weather Forecasters

As this article mentions, it's unusual around here for the temperatures to be above 90 degrees Fahrenheit (32o C). We usually get a few such days in summer. It's a once in a century event to have a day over 100o F (38o C). Clearly, it's an unusual phenomenon.

So, do you think all the putzes who complain about how it hasn't been hot recently so there must not be any such thing as climate change will be noting this record heat wave? Not bloody likely. Nate Silver of Five Thirty-Eight, who is a statistician, took one of them to task a couple of weeks ago:

John Hinderaker at the popular conservative blog PowerLine reports that it's been cold, cold, cold in his home town of Minneapolis, Minnesota, going to far as to compare it with "The Year Without a Summer", 1816, when global temperatures were abnormally low as a result of the eruption of Mount Tambora:

I don't think things are quite so bad this year, but if something doesn't change pretty soon 2009 may go down in history, in some parts of the U.S. at least, as another year with barely any summer. Here in Minnesota and across the Midwest, temperatures are abnormally cold. I don't know whether the phenomenon is world-wide--data that will answer this question have probably not been assembled, and may not be honestly reported--but the current low level of solar activity suggests that the cooling trend could indeed be universal.

Indeed, it's been pretty cool in Minneapolis for the past couple of days; the temperature hasn't hit 70 since midday Thursday. But has it been an unusually cool summer? No, not really. Since summer began on June 21st, high temperatures there have been above average 15 times and below average 13 times. The average high temperature there since summer began this year has been 82.4 degrees. The average historic high temperature over the same period is ... 82.4 degrees. It's been a completely typical summer in Minneapolis, although with one rather hot period in late June and one rather cool one now.

A Challenge to Climate Change Skeptics

[link from original]

This is the sort of dishonesty typical of warming deniers. They cherry-pick a few bits of data that supports their premise, and ignore the rest. I tend to resist using the term "global warming", because it's a misnomer. A globe is a model of the world, not our world itself. Nevertheless, that name for the phenomenon evokes the idea that this is happening over the world as a whole, not in one little portion of it.

Nowhere is this better demonstrated than by the response to the challenge Nate referred to in that article. It was to writers of major blogs (those with an Alexa ranking of 50,000 or lower). The challenge he issued was this:

The rules of the challenge are as follows:

1. For each day that the high temperature in your hometown is at least 1 degree Fahrenheit above average, as listed by Weather Underground, you owe me $25. For each day that it is at least 1 degree Fahrenheit below average, I owe you $25.

2. The challenge proceeds in monthly intervals, with the first month being August. At the end of each month, we'll tally up the winning and losing days and the loser writes the winner a check for the balance.

3. The challenge automatically rolls over to the next month until/unless: (i) one party informs the other by the 20th of the previous month that he would like to discontinue the challenge (that is, if you want to discontinue the challenge for September, you'd have to tell me this by August 20th), or (ii) the losing party has failed to pay the winning party in a timely fashion, in which case the challenge may be canceled at the sole discretion of the winning party.

A Challenge to Climate Change Skeptics

In other words, over a stretch of time more meaningful than a few days, he was willing to bet that temperatures would be warmer than average more often than not, at least if he had people betting against him from more than one place.

To date, not one of them has accepted the challenge, but what one right wing blogger attempted to do demonstrates the intellectual dishonesty of their arguments:

I did get a few feelers, most notably from Tom Maguire at JustOneMinute.com, who was willing to take the wager provided that we made the location Minneapolis, rather than his hometown of New York. This was smart of Tom, since Minneapolis is one of the few areas of the country projected to have below-average temperatures over the next 30-60 days. Unfortunately, I am smart too, so I turned him down. You can read more of the friendly exchange we had at his site.

Climate Challenge Update

[links from original] Maguire cherry-picked the data. Go figure.

So, I don't expect that we'll be hearing much from these folks about the heat wave in the Pacific Northwest. When we do, all of a sudden they'll remember that the warming or cooling of the earth happens at a more significant period than a few days, and they'll pick a slightly longer one. Either that, or they'll point out that it's cooler in Minneapolis.

Of course, the truth is that even the results of these challenges don't mean much individually. It's the dishonest attempts to cherry pick the data that are interesting. The truth is that the world's average temperature has been getting warmer for some time, as this chart demonstrates:


This is a chart of this data, which was collected and compiled by the NASA Goddard Spaceflight Center.

Clicking on that last link will take you to the NASA GSFC main page on the Earth's surface temperature. Every chart shows an increase in temperature. Charts that go back to the late 19th Century all show this trend, whether the information is compiled from weather station data or sea surface temperature measurements. Satellite surface temperature measurements confirm that trend, at least for the relatively short time they've been available. What's more, as this paper notes, that change can be attributed to greenhouse gases:

Global surface temperature has increased ≈0.2°C per decade in the past 30 years, similar to the warming rate predicted in the 1980s in initial global climate model simulations with transient greenhouse gas changes. Warming is larger in the Western Equatorial Pacific than in the Eastern Equatorial Pacific over the past century, and we suggest that the increased West-East temperature gradient may have increased the likelihood of strong El NiƱos, such as those of 1983 and 1998. Comparison of measured sea surface temperatures in the Western Pacific with paleoclimate data suggests that this critical ocean region, and probably the planet as a whole, is approximately as warm now as at the Holocene maximum and within ≈1°C of the maximum temperature of the past million years.

Abstract Of Hansen, et. al, 2006

What do those models predict will happen in the near future? More of the same, I'm afraid:

This quote from the paper explains what those different scenarios mean:

The congressional testimony in 1988 (13) included a graph (Fig. 2) of simulated global temperature for three scenarios (A, B, and C) and maps of simulated temperature change for scenario B. The three scenarios were used to bracket likely possibilities. Scenario A was described as "on the high side of reality," because it assumed rapid exponential growth of GHGs and it included no large volcanic eruptions during the next half century. Scenario C was described as "a more drastic curtailment of emissions than has generally been imagined," specifically GHGs were assumed to stop increasing after 2000. Intermediate scenario B was described as "the most plausible." Scenario B has continued moderate increase in the rate of GHG emissions and includes three large volcanic eruptions sprinkled through the 50-year period after 1988, one of them in
the 1990s.

Global Temperature Change [Hansen, et. al. (PDF)]

The conclusion I draw from this is that even in the most wildly optimistic scenario, Scenario C, the temperature of the world's surface will stay as it is. The most likely thing is that it will continue to increase at about the same pace it has been.

Other climate models agree with the outlines of that 1988 model. They all see the temperature rising. The only disagreement is over how much it will rise.

Our world is warming up, and that warming is at least partly due to the effects of the greenhouse gases, including carbon dioxide, that people are creating. To ignore this information because Minneapolis is cooler than usual this month, or similarly localized observations, is the height of stupidity.

UPDATE: As the Seattle PI reports, it was a record day. Temperatures hit 103o F at SeaTac Airport, Boeing Field, and Tacoma Narrows Airport, which are the three nearest official weather stations to me.


2 comments:

Dana Hunter said...

Don't want summer anymore. Want winter. Winter gooood.

I miss the days before climate change really started kicking in... At least by the standards of global warming denier evidence, I now have a statistic to beat them over the head with. Won't convince them, but at least we can make 'em made by pointing out their rampant hypocrisy.

Cujo359 said...

Yes, they'll probably treat this as anomalous data, rather than things like Minneapolis. Having their point of view really just requires selective attention to information.