Throughout most of central Canada, where I live, as well as the north-central US (west of the Great Lakes), we’ve had a very cool spring and summer. It feels like we’ve only had a few days of actual summer. My shorts are sitting at the bottom of my closet wondering why I’ve rejected them.
The media has been all over this. Skeptical websites are thrilled. I’ve heard way too many “So much for global warming!” comments for my comfort and sanity. There are only so many times that I can patiently explain the difference between weather and climate, regional and global change before I go a little nuts.
I made an uneducated assumption that the world was still around 2008 temperatures. Perhaps it was due to a solar minimum, the last dregs of La Nina, or just statistical noise. I didn’t think too much about it.
It was a bit of surprise yesterday, then, when I read a blog post that suggested that the southern US was experiencing above-average summer temperatures. I was quite intrigued. I went on a search for a global temperate anomaly map for this spring and/or summer. Here is a map from the National Climatic Data Center (part of NOAA).
As you can see, north-central North America did have below average June temperatures (not too surprising to me – the jet stream almost reached Chicago the other day). So did parts of Asia, Europe, and South America. But it’s clear that these cooler areas are the minority. Almost everywhere else on our planet (including the southern US) had a warmer than average June.
The NCDC states that the global land-and-ocean temperature for June 2009 (basically the map you see above) “was the second warmest on record”. They also note that, during June, an El Niño began. As the global temperature increases during an El Niño event, due to a change in heat exchange between the ocean and the atmosphere, the NCDC predicts that “global temperatures are likely to continue to threaten previous record highs”.
There’s a good chance that it won’t be long before we stop hearing that global warming stopped in 1998. In a way, that makes me happy – no other claim annoys me quite so much, can you say statistical misrepresentation – but it also makes me worry about the state of the world.
I wish I was wrong about this. I wish that global warming had really stopped in 1998.
June 2009 alone can’t prove a warming trend – it doesn’t even come close to the classical 30-year climate period. But it really makes the “so much for global warming” hypothesis in my area fall apart. That claim was unscientific even before we knew the stats for the whole world. How can you possibly discern an idea of global climate from a few months in a single area?
There’s a reason it’s called global warming, not regional warming.
There’s a reason it’s called climate change, not weather change.
And hooray for scientific data that is readily available to the public, so we don’t have to rely on personal experience of our own little corner of the world to try to figure out the whole planet.
And just in case you want more, there was a great paper published in GRL looking at this issue.
They authors conclude:
The reality of the climate system is that, due to natural climate variability, it is entirely possible to have a period as long as a decade or two of ‘‘cooling’’ superimposed on the longer-term warming trend due to anthropogenic greenhouse gas forcing… [and] it is clear that the models can and do produce sustained multi-year periods of ‘‘cooling’’ embedded within the longer-term warming produced in the 21st century simulations
And I wrote about it here:
It is a shame that this talking point will continue ot live despite being totally debunked.
Hey Dan, thanks for visiting and participating in the discussion. It’s great to see other people that are interested in this issue.
That’s an interesting link, it really proves how you have to look at trends in a long-term perspective, you can’t cherry-pick bits and pieces. I’m working on a video that discusses how the Earth’s temperature is impacted by different factors, many of which constantly change, so it’s impractical to believe that “global warming = every consecutive year is warmer than the last”.
Sadly we’re not all scientists in this world. I wish we could all be trained to think as such.
“There’s a good chance that it won’t be long before we stop hearing that global warming stopped in 1998. In a way, that makes me happy – no other claim annoys me quite so much, can you say statistical misrepresentation – but it also makes me worry about the state of the world.”
I know exactly how you feel. I would love for it to be colder, since, you know, it is good to stop this warming. But the debater in me would just LOVE for it to get hotter.
However, I don’t think that claims about global warming stopping are going to cease. The people who make that argument are so horribly misinformed; so what reason do we have to believe that they will know what the 2009 temperature is?
I’ll have to agree with mtgandp; the claims will never disappear. In fact, as I mentioned in my blog post today, for all the many ‘we’ve been cooling the last 10 years’ comments, in fact, if you compute the 10 year trends month by month over the last 15 years, at no time was it true to say that there was a 10 year cooling trend. I confess I was surprised that even letting people cherry pick their starting times, even with as anomalously warm as it was in 1998, there _still_ was no 10 year cooling trend.
I’ll have to go read that post, it sounds interesting. I’m subscribed to your blog but that post hasn’t showed up in my RSS reader yet…I guess there’s a lag time.
I’ve heard “we’ve been cooling for the last 15 years” (?!)
I also heard, in a very strange letter to the editor, that “since Al Gore released his film, the world has cooled by about 3/4 of a degree Celsius”. I believe An Inconvenient Truth came out in 2006. So in three years, 0.75 C global cooling?? Does this guy realize how obviously made-up that is?
Evidently your letter-to-the-editor guy thinks that connect-the-dots is valid statistical regression technique. Although he’s doing great work where he is now, sometimes I wish Tamino did house calls (or had a hit squad of crack statisticianinjas; same difference).
Kate, you might check out your settings on the refresh frequency in your RSS reader. My note was up early on the 20th.
The ’15 years cooling’ is a strange claim in its own right. There are two lines for it. One is the straightforward lie. The other is where an Australian politician (Fielding) said in one place ’15 years without warming’, and then continued as if it were shown to be cooling. The ‘without warming’ turns, to the degree it might be vaguely honest, on inserting (and honestly evaluating) whether the trend is statistically significant. Politicians (regardless of nation or party) aren’t where I’d turn for an evaluation of such matters. Then again, there is the fact that 15 years is short for making statements about climate.
The ‘since the film release’ involves a typical denier lie method. Namely, pretend that you compute trends by taking some specific month (cherry picked of course) and then some other (also cherry picked) month and pretend that the trend is the difference between those two numbers. Given the natural variability, you can get some pretty wild trends (April-May this year shows a 120 C/century temperature trend!) if you engage in such cherry picking.
Ah, per-century might easily explain it. I only learned about that degrees/century way of measuring a few weeks ago. I was talking to a climatology prof that I know and he showed me a map he and a student had made of the rate of temperature change in Canada since the 1970s (can’t remember the exact date). For spring, summer and fall, the warming was pretty modest, but for winter….almost all of Canada was the darkest colour of red they had on the anomaly key, representing a warming of 10 C/century. But I had never heard that way of measuring before, so I interpreted it as 10 C warming since the 1970s and totally freaked out. But then the prof explained it to me and I relaxed….a little.
Another good story is the time I was reading an editorial from the States (I think it was actually the Krugman one) that said, “scientists are predicting the world could warm as much as 9 degrees by the end of this century.” I was really shocked….until I realized it was in Fahrenheit. :)
IIRC there are some “long tail” projections with extremes at least close to 9C, so no need to be disappointed. :)