More evidence of global warming.

[d000hg]

118 is the ranking. Muppet. The clue is in the word 'National'.

Source.

Perhaps if you posted charts which actually explained what they were showing such confusion wouldn't arise.

[Taita]

More evidence of global warming

The world is close to reaching tipping points that will make it irreversibly hotter, making this decade critical in efforts to contain global warming, Australian scientists warned.

Scientific estimates Australia's temperature looks set to rise by six degrees Celsius by 2012 if greenhouse gas emissions are allowed to rise uncontrollably.

"This is the critical decade. If we don't get the curves turned around this decade we will cross those lines," said Will Steffen, executive director of the Australian National University's climate change institute, speaking at a conference in London just a few months before it snowed this spring.

"Scientific estimates Australia's temperature looks set to rise by six degrees Celsius by 2012 if greenhouse gas emissions are allowed to rise uncontrollably."
Only a couple of months left to save the Koala then we will be in 2013!

[sasguru]

The global temperature trend over 15 years

Can you please explain how the trend (red line) has been calculated?
And what the units on the y-axis represent?

[EternalOptimist]

Can you please explain how the trend (red line) has been calculated?

it's statistics sas.

there was a cold snap one year ,1997. the eco loons strart their trend line in the cold snap so they always show massive warming
people who want to show cooling start their graphs at a high point

thats why I always take pjs offerings with a pinch of salt

this graph seems to fall between the two

[BlasterBates]

Can you please explain how the trend (red line) has been calculated?
And what the units on the y-axis represent?

linear least squares regression

Y axis - temperature anomalie from HADCRUT (Climate research unit - East Anglia University - global temps)

[d000hg]

Now can you explain the Y-axis in English? You and pj are as bad as each other, plastering impressive looking graphs to back your argument without explaining in lay terms what the graph is showing.

[pjclarke]

SAS - Its from the website Wood for Trees: Home, which is reliable. The trend is OLS. Blaster has cherry-picked a period and chosen an obsolete global dataset, HADCRUT3, which has been superceded by HADCRUT 4.

Judith Curry, in the blog post linked above says that you need a longer period to eliminate the effects of natural variability. 15 years is unlikely to be statistically significant, and is just long enough to embrace the most powerful El Nino of the last century in 1998 which brings warm water to the sea surface, and which pushed temps 2 sd above the trend line, and a series of LA Nina events towards the end which have the opposite effect, hence the depressed short-term trend amongst the long term one.

Hardly anything new

[pjclarke]

Now can you explain the Y-axis in English?

Its an anomaly plot, that is the variance from a defined baseline average temperature for the globe. From the source

The main temperature series we have on this site - HADCRUT3, GISTEMP, UAH and RSS - are all expressed as monthly temperature anomalies from a defined baseline period. This means that the average temperature for each similar month (all Januaries, all Februaries, etc.) is subtracted from the monthly value to remove any seasonal cycle, and (in theory) any difference between the absolute starting positions of the series.

HADCRUT is a gridded average of the surfcae - that is, the globe is divided into grid cells, an average of all the temperatures in each cell is calculated and the average of the cells computed. UAH and RSS are satellite products that actually measure the lower atmosphere rather than the surface - but give a remarkably similar result.

[BlasterBates]

I see pj's analysis only uses 8 year periods....which is why the climate scientists suggests that a pause of at least 15 years would be necessary for it to be significant. Of course the graph breaks up the 15 years pause which is evidently there, as I demonstrated.

Well it is now 15 years and counting.


Here's a challenge that might be somewhat more impressive as a counter argument. Try finding a 15 year period prior to 1997 during the warming after AGW took off after 1980.


Pj correctly points out how global temperature variation are driven by EL Nno and La Nina. Since 1980's we have had predominant El Nino's. Well to push the temps up again to fit model predictions an EL Nino is badly needed:

Lets see what's happening:





Oh it's going back down again....if it goes into La Nina it will drive global temps further down.

It doesn't look good at all ....

[EternalOptimist]

The reason why I dont like to refer to temperature data, even when it supports my view, and the reason why i dont get all excited about these graphs, is that the data underpinning them is entirely suspect.
The historical record is not what it seems. Maybe the satelite data will give us a firmer footing in the future, but the historical data has been adjusted so many times that it is worthless in my opinion.

In addition to that, I just dont see the point in this measurement at all anyway.
If you want to know how hot your bath is, you dont look at a thermometer on the wall. do you ?