Global Warming for Dummies

[threaded]

Thought I'd pitch in again with the comment that the modern temp data has been shown to be dodgy.

Common statistical tests showed it to be bogus years back.

Since then it was found the Russians were copying summer data over onto the winter data and several of the loons in the AGW camp have also been caught faking the data.

So... you have to be careful about who's data you're talking about.

[sasguru]

Common statistical tests showed it to be bogus years back.

.

Ah finally an assertion that can be debated.
Proof?

[DS23]

where do you go once you've learnt vb really well?

[pjclarke]

Roy Spencer and Richard Lindzen were the 2 who answered no to Q2, I speculate. Spencer is free to post whatever he likes on his blog, of course, though it rarely stands up to scrutiny.

His publications that have survived peer-review and made it into the literature tell a rather different story. There is also a question mark over his mathematical ability - he posted a regression analysis showing 'remarkable correlation', when his technique would have shown the same correlation between any two variables plucked at random.

Ho Hum. Regarding the CO2 correlation with global temp, suppose for a moment that there was in fact, no increasing greenhouse influence on the temperature. Would you expect it to trace a perfectly horizontal straight line? Of course not, there is noise in the signal - the solar cycle and natural variability and other factors cause the trace to zigzag. So why would anyone expect a perfectly straight positively-sloped line in the presence of an external forcing? The reality is that over the shorter term the 'zigzags' can temporarily swamp the greenhouse signal, but take a longer view and the 'noise' averages out, leaving a rising curve correlated well with the increase in greenhouse gas concentrations.

[BlasterBates]

take a longer view

So in 1988 they proclaimed a few years of global warming was due to CO2.

Works one way but not the other, 12 years is significant in the 30 years or so of warming. Is it not?

and if not why was Jones worried?

that's interesting, and that was in 2005, the statistically insignificant cooling trend is now 12 years not "just 7"

...oh and remember the Satellites show a statistcally significant cooling.

the solar cycle

So it is recognised now as a factor...well well, isn't that weird as the solar cycle weakens the earth cools...well well

What about that suppressed spectral analysis that showed a strong correlation between the solar cycle and temp?

That's interesting

[DS23]

do we still get acid rain?

[DS23]

how big is the ozone hole now?

[Spacecadet]

how big is the ozone hole now?

that was plugged using some spare rainforest

[BlasterBates]

how big is the ozone hole now?

Bigger than it's ever been in spite of CFC's being banned 20 years ago:

http://earthobservatory.nasa.gov/IOTD/view.php?id=7044

[pjclarke]

Thought I'd pitch in again with the comment that the modern temp data has been shown to be dodgy.

Common statistical tests showed it to be bogus years back.

Since then it was found the Russians were copying summer data over onto the winter data and several of the loons in the AGW camp have also been caught faking the data.

So... you have to be careful about who's data you're talking about

Indeed. You have evidence of faked data, I presume, that's a fairly serious allegation. I suspect the 'copying over' reference is to an incident where some of the data supplied monthly to the NASA temperature index (GISTEMP) was carried over from the previous month, embarrassing - but the issue was spotted and corrected within a few days.

There are four main global temperature indices, HADCRUT and GISTEMP from the UEA and NASA Goddard Institute respectively which measure surface temps, and UAH (maintained by Spencer and Christy) and RSS which take tropospheric readings from weather satellites and convert them to temperatures. All four have slightly differing coverage and/or methodology for deriving a global mean temperature.

Satellite coverage is from 1979, while the surface instrument record goes back to before 1900. The NASA uses data in the public domain, and they have released the source code for their calculations, while a small fraction of the source data for HADCRUT is owned by National Weather Services who place restrictions on it.

The difference between the HADCRUT index and the 100% open source GISTEMP is insignificant. The difference between the HADCRUT index plotted with just the public domain data and all the data is insignificant, the differences between the satellite indices and the surface-based indices are insignificant.

So if one of the data products is 'dodgy', then logically, they must all be. I am sure we are all longing to hear exactly how they are dodgy, and who was caught faking the data...