Thursday, February 08, 2007

Falling sky

Global warming's in the news a lot lately, thanks to a recent report by a panel of scientists that claims, with 99% certainty, that man is causing temperatures to rise around the globe. I won't repeat all the dire predictions, because I'm sure you've heard about them already, but suffice to say they paint a pretty gloomy picture.

I don't have the energy to debunk the entire global warming myth for you, so let's just focus on this report instead.

** Edit **

If you read my post earlier in the day, I apologize for the errors I made - basically I had mixed up this IPCC report with an earlier IPCC report on global warming. Some of the criticisms and rebuttals I linked to were actually crticisms of an earlier report. The main reason for this was that I had not realized the current IPCC release is only the "Summary for Policymakers" section - the actual details of the study won't be released until May.

At first reading of the IPCC release, I was impressed by the scientific sheen of the presentation. The numerous graphs and over-my-head discussion of carbon-climate feedback had me wondering if perhaps I was being too cavalier by dismissing the grim specter of global warming.

A few minutes on Google did wonders to cheer me up.


  • The four-degree temperature increase that was widely reported as a foregone conclusion relies upon a doubling of carbon dioxide concentration in our atmosphere over the next century. Since the current rate is 379ppm (compared to a pre-industrial concentration of 280ppm, although ice core samples show that it has previously been as high as 300ppm), and it is growing over the last 10 years at 1.9ppm, the assumption is that it will grow twice as fast over the next 100 years. This figure can only be true if one presumes robust global economic growth without any corresponding increase in technology and energy efficiency.
  • The disastrous sea-level predictions, which have actually moderated since previous IPCC publications, rely on a nearly-complete melting of the Greenland ice sheet. No mention in the "Summary for Policymakers" of Johannessen's 2005 research that found the Greenland ice sheet has instead expanded since 1993. This research fits perfectly with an independent study from Petr Chylek at Los Alamos, who found that Greenland's surface temperature has in fact decreased a stunning 2.2 degrees since 1987.
  • The dire forecasts of polar ice melt and increased arctic temperatures gloss over the fact that arctic ice temperatures warmed twice as fast from 1917-1937 as they are currently, and peaked at a higher temperature in 1938 than today. 1940 saw the beginning of an arctic cooling period, most likely brought on by a shift in ocean currents that occurs naturally on a 30-40 year cycle, known as the Pacific Decadal Oscillation. Coincidentally, perhaps, the latest shift in the PDO occurred in 1970, and this correlates roughly with the rapid increase in arctic temperatures.
  • The ice-cap melting, as well as the "Northern Hemisphere Snow Cover" chart, both focus squarely on (obviously) the Northern Hemisphere, ignoring temperature readings that show a stastically insignificant decrease in Southern Hemisphere temperatures over the last 25 years. They also ignore data that demonstrate Antarctic cooling since the 1960s, and increased Antarctic sea ice cover. Note that you won't find a "Southern Hemisphere Snow Cover" chart in the publication, despite the clear and repeated emphasis on "global" climate change.
  • The familiar "hockey stick" temperature graphs over the last 150 years fail to acknowledge or explain a rapid increase in global temperature from 1910-1940, and a rapid decrease in global temperature from 1940 to the 1960s. You'll note that much of the alarmist global warming rhetoric talks about the rise in temperatures from 1970 to present - which deceptively discounts the unexplained prior decrease. Furthermore, the IPCC report mentions the "urban heat island effect", but does not adjust its numbers for it, calling the effects "negligible". And finally, the temperature graphs inexplicably end in the year 2000, perhaps because there has been no temperature increase since 1998.


Also note the language throughout the document. Phrases like "is consisent with" and "very likely" are ubiquitous. There's plenty of correlation, but no demonstrated causality. We do not currently have enough knowledge of climate to understand what causes the variability we observe. This does not mean that we should assume causality from correlation! To the ancient Greeks, the sun moving across the sky was consistent with Apollo dragging it in a giant chariot. They lacked knowledge, and they made their best guess using their limited understanding of the world, but they obviously missed the truth by a wide margin.

Look, I'm not a apologist for polluters. I don't believe it's smart to pump garbage into our atmosphere when we don't really understand what effects it might have. But I do think policy should be based on science and reason, not emotion. If we want to find a clean, renewable energy source - and I'm all for that - the worst thing we can do is create a bunch of restrictive regulations that are based on unscientific propaganda. The political and economic incentives are already in place (Middle East, Hugo Chavez, etc.), so the best thing we can do is get out of the way and let the market do its work. A vibrant and innovative global economy is our best chance to discover and implement the technology required to both meet our power needs and act as caretakers to our environment.

2 Comments:

At 4:22 PM, Anonymous tommy said...

On July 24, 1974 Time Magazine published an article entitled "Another Ice Age?" Here's the first paragraph:

"As they review the bizarre and unpredictable weather pattern of the past several years, a growing number of scientists are beginning to suspect that many seemingly contradictory meteorological fluctuations are actually part of a global climatic upheaval. However widely the weather varies from place to place and time to time, when meteorologists take an average of temperatures around the globe they find that the atmosphere has been growing gradually cooler for the past three decades. The trend shows no indication of reversing. Climatological Cassandras are becoming increasingly apprehensive, for the weather aberrations they are studying may be the harbinger of another ice age."

Just thought that was interesting.

 
At 11:19 AM, Blogger Sweet Tea said...

Precisely.

Your example shines light on a few important points about the global warming debate.

1) "Global" actually means "North American", as in both cases, the temperature shifts observed were felt north of the equator, while the Southern Hemisphere remained relatively constant or moved slightly in the opposite direction. This is entirely consistent with the hypothesis that these temperature shifts are brought on by ocean currents on 30-40 year cycles like the PDO.

2) Environmental "scientists" who are desperate for grant money, publicity, and relevance, are all too eager to extrapolate short-term trends into long-term disasters, when the scientific evidence strongly suggests that the short-term trend is...short-term.

 

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