Another Foray Into Climate Science
As always, my role is the amateur plunging into a pool of expertise. On Thursday, George Will quoted Mark Steyn to the effect,
If you’re 29, there has been no global warming for your entire adult life. If you’re graduating high school, there has been no global warming since you entered first grade.
Kevin Drum dismissed Steyn’s comment as a denialist talking point:
Global temps have been trending up for over a century, but in any particular year they can spike up and down quite a bit. In 1998 they spiked up far above the trend line and last year they spiked below the trend line. So 2008 was cooler than 1998.
Kevin provides the relevant graph to make his point. 
I found the graph interesting for several reasons. First of all, it shows that global temperatures were falling from around 1940 through 1975. Then there were big jumps in the late 70s, late 80s and late 90s. Whatever’s happening to our planet’s temperatures, they certainly aren’t holding steady.
Anyhow, Kevin’s post (along with those of Ezra Klein and Ryan Avent) led Jim Manzi to defend Will and Steyn on the grounds that they are, at a minimum, technically correct, since average temperatures haven’t risen over the past ten years, regardless of what’s happened over the past thirty-five. Jim also raises some very interesting questions about how much data we actually need to know whether the globe is warming or not. He admits that ten years of stability doesn’t mean much. But how many years of data do we actually need to come up with good answers about the existence/extent of global warming?
Finally, there’s one last response from Kevin in which he takes Jim to task for saying that temperatures have been stable over the past decade, since they actually have risen (by one-fifth of a degree (Celsius) to be precise). Kevin’s baseline year is 1999. Compared to 1998 (a hot year), it seems temperatures have actually fallen slightly. I think Kevin’s argument would’ve been much more robust if he said that the average temperature for the past ten years was significantly higher than the average temperature for the decade before that.
So all I need to figure out is what the average temperature will be a decade from now.
Cross-posted at Conventional Folly
5 Responses to “Another Foray Into Climate Science”
The real issue is how long a time frame do you use? The global climate has undergone massive changes in temperature well exceeding what current fluctuations when you use longer timescales. And given the number of known long-term cycles that effect our climate, even a hundred-year base-line is not likely to give you much of a predictive model.
There is still so much that is unknown about the interactions that influence our climate, and no firm model that has shown consistent predictive capabilities.
http://www.scotese.com/climate.htm
http://www.climatechangefraud.com/temperate-fac…
http://www.john-daly.com/hockey/hockey.htm
http://www.drroyspencer.com/latest-global-tempe…
http://wattsupwiththat.com/2009/07/03/uah-globa…
You can even make completely unrelated phenomenon appear to track global warming.
http://joannenova.com.au/2009/05/03/shock-globa…
John Daly is not a scientist and has no particular respect for real science. Realclimate, which is a site done by actual climate researchers addresses the myths of the hockey stick here.
Dr. Roy Spencer in spite of what looks like a fairly respectable scientific background just isn't a reliable source for objective information. Like many of the deniers, he has wonderful credentials when it comes to politically conservative organizations. He also denies that evolution is real and frankly that doesn't do a whole lot for his scientific credentials. His and Christy's satellite research that they claimed provided evidence against global warming was proven incorrect in 2005. He and Watts tend to show that there is no one less interested in real climate science that ideologically driven older meteorologists.
First up, as you review this stuff going forward, please note that denialist web sites (and of course they are usually web sites and think tank papers, not science journal articles) argue two main points: 1) temperatures are going up and this is due to non-human related changes, with the sun typically given cred. Next they say 2) actually temperatures aren't going up and we are stable or in a cooling period. Unqualified, these two claims flatly contradict one another. We are warming up due to the sun and we are cooling. Warming and cooling. This COULD be consistent if they were talking about different time periods, but, while I'm no expert in denialist lit, that is not the normal claim. The whole point of the sun argument is to be able to acknowledge evidence of warming when they can't get rid of it but not lay blame on man. If you've got to admit that glaciers are retreating, then you blame it on natural warming cycles. But you can't then turn around and claim we are cooling as well.
Next up, if this graph was anything but average global temps, would anyone deny the obvious trend upwards? I mean, if this was a graph of PRC military expenditures or annual deficit as percent of the GDP, would the same (usually politically conservative) organizations not be sure if there was an upwards trend or not? It's obviously going up.
And then the “cooling” idea is exclusively based upon picking that 1998 year as the baseline. The cherry picking is disguised with neat rhetorical tricks: “if you are 29″ or “if you are graduating high school then since first grade”, which all just means since 1998. Because, if you are 30, well, things have been warming since you became an adult (12 years ago falls on 1997, not 1998), and if you are 31, and if you are 32, and if you are 28, 27, 26…. all warming. Every year in the 2000s has been warmer than every single other year in the entire graph (literally) for a century except for 1998. Moreover, we know some of the reasons for 1998's abnormality (mostly a particularly intense el nino event). Finally, while I don't have the numbers, since every single year in the 00s is higher than every year in the 90s, except one, then the average for the 00s is certainly higher than it is for the previous decade. Looks like you have to move back to a 60s and 70s comparison before that may not be the case.
All you have to do is draw a simple trend line for your hot peaks and another for your cool troughs. You can clearly see the trend is UP UP UP in both circumstances.
Do not use politically motivated sources for your research. Contact the National Science Foundation(NSF), University Corporation for Atmospheric Research (UCAR), National Center for Atmospheric Research (NCAR), National Oceanic and Atmospheric Administration (NOAA), Scripps Institute for Oceanography, California Institute of Technology, to name a few American sources. There are many other sources from outside the United States also. I suggest concentrating on at least the top 20 climate modelers current models with variables, and their data sources.
You will be getting the best information and not political opinion. You will find interesting information regarding climate change historically over thousands of years from ice core samples taken from Antarctica. The deeper you dig, you will find ongoing models created from constant and periodic atmospheric particle sampling and light measurements.
Should you study with intellectual honesty, I’M CERTAIN, that you will come to the conclusion that there is much legitimate and troubling concern regarding climate change and global warming. Believe me, these world wide research scientists confront each other over data, verifications, measurements, models etc., constantly and ferociously. No bunk science is going to get by I assure you.
“Next up, if this graph was anything but average global temps, would anyone deny the obvious trend upwards?”
Sure, if that were a stock market chart, we'd be hearing “highly overvalued,” “headed for a calamitous crash.”
The problem is that both questions–”has it been getting hotter?” and “is it our fault?” aren't the right ones to be asking, because they're both about the past.
The question that matters is “what will happen if we adopt policy X?” Since this is about the future and depends on speculative climate and economic models, the answer is harder to determine and less fun to write about than how the other guys are a bunch of big doo-doo heads.