Are we going for a random walk?

[DimPrawn]

Is global temperature a random walk?

All this talk of idiots trying to make money on financial instruments, when many believe price data is a random walk, made me think.

Is the global temperature a random walk? Is the Hurst exponent of the global temperature timeseries close to 0.5?

The surprisingly weak case for global warming | (R news & tutorials)

Over to you pj clarke (and sasguru)

[pjclarke]

Check out the comments.

The surprisingly weak case for global warming « Probability and statistics blog

The hypothesis of a random walk may work from a purely statistical standpoint (though a purely Bayesian approach fails), but the author is not trying to model the physics. There is no plausible physical explanation for the trend other than an external forcing of some kind. Basically, increasing the global temperature (the signal) requires a HUGE input of heat way beyond that explained by natural variation (the noise).

For an informed treatment of physics-based statistics try the blog 'Open Mind', run by a professional statistician, who literally, 'wrote the book'. Here he is on the alleged recent 'pause' in GW

Too Little Time | Open Mind

[DodgyAgent]

Check out the comments.

The surprisingly weak case for global warming « Probability and statistics blog

The hypothesis of a random walk may work from a purely statistical standpoint (though a purely Bayesian approach fails), but the author is not trying to model the physics. There is no plausible physical explanation for the trend other than an external forcing of some kind. Basically, increasing the global temperature (the signal) requires a HUGE input of heat way beyond that explained by natural variation (the noise).

For an informed treatment of physics-based statistics try the blog 'Open Mind', run by a professional statistician, who literally, 'wrote the book'. Here he is on the alleged recent 'pause' in GW

Too Little Time | Open Mind

Anyone that calls themselves "open mind" is usually anything but

[BlasterBates]

More evidence of climate change

First evidence that glaciers maybe turning in the alps.

Glaciers growing in Italy

They´re still receding in Switzerland but with heavier snows and longer winters, lets face it it´s just a matter of time.

I´m enjoying the huge amount of egg spreading on the faces of climate scientists. Surely when they look out their windows and see huge amounts of snow in April all over the Northern Hemisphere, they must begin to get the message.

[OwlHoot]

I´m enjoying the huge amount of egg spreading on the faces of climate scientists. Surely when they look out their windows and see huge amounts of snow in April all over the Northern Hemisphere, they must begin to get the message.

The only people not getting the possible, or very likely, message are moobs like you and other climate change scoffers, who insist on judging solely by appearances!

As I've often trotted out here, I once had a student job in an ice cream factory. They maintained large walk in freezers at -20C, and usually one barely noticed the cold near the entrances, even standing right by the plastic flaps as people constantly walked in and out, although it hit you like a blanket as soon as one barged through the flaps!

But the one exception was when the freezers were being defrosted, and at those times it felt very damp and uncomfortable anywhere near them, even many yards away, as they were getting much warmer.

The moral of the story, for those too willfully stupid to work it out, is that melting ice caps and ice cover at the poles and in places like Greenland can, paradoxically, make the weather further south seem much colder. But it won't last.

[DimPrawn]

Check out the comments.

The surprisingly weak case for global warming « Probability and statistics blog

The hypothesis of a random walk may work from a purely statistical standpoint (though a purely Bayesian approach fails), but the author is not trying to model the physics. There is no plausible physical explanation for the trend other than an external forcing of some kind. Basically, increasing the global temperature (the signal) requires a HUGE input of heat way beyond that explained by natural variation (the noise).

For an informed treatment of physics-based statistics try the blog 'Open Mind', run by a professional statistician, who literally, 'wrote the book'. Here he is on the alleged recent 'pause' in GW

Too Little Time | Open Mind

Back to my original thoughts.

http://economics.huji.ac.il/facultye...aper091209.pdf

We use statistical methods designed for nonstationary time series to test the anthropogenic theory of global warming
(AGW). This theory predicts that an increase in atmospheric greenhouse gas concentrations increases global temperature permanently. Specifically, the methodology of polynomial cointegration is used to test AGW when global temperature and solar irradiance are stationary in 1 st differences, whereas greenhouse gas forcings (CO2, CH4 and N2O) are stationary in 2nd differences.

We show that although greenhouse gas forcings share a common stochastic trend, this trend is empirically independent of the stochastic trend in temperature and solar irradiance. Therefore, greenhousegas forcings, global temperature and solar irradiance are not polynomially cointegrated, and AGW is refuted.

Although we reject AGW, we find that greenhouse gas forcings have a temporary effect on global temperature. Because the greenhouse effect is temporary rather than permanent, predictions of significant global warming in the 21st century by IPCC are not supported by the data.

So basically, statistically speaking, the IPCC findings are bollox.

[pjclarke]

More snow does not mean colder. It is an expected consequence of the melting Arctic Ice.

Our study demonstrates that the decrease in Arctic sea ice area is linked to changes in the winter Northern Hemisphere atmospheric circulation,” said Judith Curry, chair of the School of Earth and Atmospheric Sciences at Georgia Tech. “The circulation changes result in more frequent episodes of atmospheric blocking patterns, which lead to increased cold surges and snow over large parts of the northern continents.

Impact of declining Arctic sea ice on winter snowfall | Climate Etc.


Also, the trick of cherry-picking areas of cold weather (copyright Anthony Watts) misses the big picture...

Freezing cold in Siberia, reaching across northwestern Europe, unusually mild temperatures over the Labrador Sea and parts of Greenland and a cold band diagonally across North America, from Alaska to Florida. Averaged over the northern hemisphere the anomaly disappears - the average is close to the long-term average.

Click.


And the 'Ice age Now' website is run by a former architect, Robert W. Felix to promote his self-published book about “the coming ice age”. Felix believes that sea levels are falling, not rising; that the Asian tsunami was caused by the “ice age cycle”; and that underwater volcanoes are responsible for rising sea temperatures. But don't feel too bad - he also duped David Bellamy.


Something about egg on faces ...

[pjclarke]

That's right, two economists at the Hebrew University have overturned the conclusions of 20,000 climate scientists. Puh-leeze.

Rabett Run: Idiots Delight
moyhu: On Polynomial Cointegration and the death of AGW
Not a Random Walk | Open Mind

[DimPrawn]

That's right, two economists at the Hebrew University have overturned the conclusions of 20,000 climate scientists. Puh-leeze.

Rabett Run: Idiots Delight
moyhu: On Polynomial Cointegration and the death of AGW
Not a Random Walk | Open Mind

Nothing there actually shows the statistical treatment is wrong?

If anything it shows they are using the correct statistical tools and the "climate scientists" the wrong ones.

Basically the warmists just scream "they aren't physicists and they questions the IPCC".

[doodab]

Nothing there actually shows the statistical treatment is wrong?

If anything it shows they are using the correct statistical tools and the "climate scientists" the wrong ones.

Basically the warmists just scream "they aren't physicists and they questions the IPCC".

Climate models may or may not be bollocks but economists are the last people i'd trust to critique them.