Monday, October 26, 2009

Recent global cooling isn't in the statistics

A nice article from Seth Borenstein, one of the better climate science reporters, tries to explain how, statistically, there is no such thing as recent global cooling.
The case that the Earth might be cooling partly stems from recent weather. Last year was cooler than previous years. It's been a while since the super-hot years of 1998 and 2005. So is this a longer climate trend or just weather's normal ups and downs?

In a blind test, the AP gave temperature data to four independent statisticians and asked them to look for trends, without telling them what the numbers represented. The experts found no true temperature declines over time.

"If you look at the data and sort of cherry-pick a micro-trend within a bigger trend, that technique is particularly suspect," said John Grego, a professor of statistics at the University of South Carolina.
I love the idea of the AP asking 4 statisticians to just analyze a time series without giving the source of the numbers.

I don't know why the satellite data is labeled by Borenstein as "preferred by skeptics". They used to like it when an incorrect analysis suggested it contradicted model predictions. Not so much after the mistake was corrected.

The gist of this article is that, in statistics, you can't just throw out the data you don't like. That's what deniers are doing when they choose to only look at the last few years or so and say: "the data says the globe is cooling". But they have no way of knowing if that is temporary or permanent. The honest thing to do is to look at all the data and that data says its warming.

9 comments:

Anonymous said...

They like UAH for a few reasons:

1) It generally has a slightly lower trend relative to the other records
2) Both sat records exaggerate ENSO relative to the instrumental records, which made the 1998 El Niño peak to 2008 La Niña trough "cooling" much more dramatic.

and of course

3) Spencer and Christy are denialist heroes

Anonymous said...
This comment has been removed by a blog administrator.
monimtw said...

hello,

I went through your website and i found it really exciting.your articles are super.

If you are interested to exchange link with my blog please add my blog to yours and let me know so that i will also include yours.
My blog is http://www.hybridcarsonline.blogspot.com

If you are not interested to please delete my message .

Hopping to hear from you,

monish

monimtw said...

hello,

I went through your website and i found it really exciting.your articles are super.

If you are interested to exchange link with my blog please add my blog to yours and let me know so that i will also include yours.
My blog is http://www.hybridcarsonline.blogspot.com

If you are not interested to please delete my message .

Hopping to hear from you,

monish

girish said...

The climate is not consistent in the recent years and in the future also it may be a problem.

menocchio said...

Is it true that when eric the red visted newfoundland there was no ice there? Is it also true there has been global cooling since the medieval warm period. If we look at time scales of thousands of years the picture we see of the temperature variation is different. Perhaps in the long run the next ice age is actually coming.

Anonymous said...

The only data that really matters to assess man's hypothetical affect on the greenhouse effect are lower tropospheric temperatures. Since the data are scarce and what we do have show no significant incline, it appears that the hysteria over manmade global warming has been quite contrived. But, no crisis, no funding, and no political issue to clamor about. Thus I don't expect the warmists to cease their crusade anytime soon. So carry on in your own denial, friend.

Anonymous said...

But they have no way of knowing if that is temporary or permanent. The honest thing to do is to look at all the data and that data says its warming.

No. The honest thing to do is to wait and see if the current cooling trend will continue, rather than destroying our economies and submitting to monitoring and control of our activities, all on the basis of what may turn out to be a bogus hypothesis.

Unless you happen to be an environmental fanatic of course, in which case, no doubt, you will want to live in a yurt and use a horse and cart for transportation and eat raw turnips for breakfast etc. Most people don't have a problem with that as long as they are not being forced to live that way themselves.

Stacy said...

It must be incredibly discouraging to write intelligently about a critical issue but receive in return only responses from ignorant deniers and self-promoters.

I quite enjoy your blog. Keep up the good work.