JBowyer

<< I have read the New Zealander's changed their data on temperature to help the, what is it again, global warming, AGW or climate change? You tell me! >>

Yes, it really is all about getting your facts right.

To repeat yet again, the New Zealand Climate Science Coalition made the NZ warming trend ‘go away’. They did this by treating measurements from different sites as if they came from the same site.

They also claim that New Zealand’s National Institute of Water and Atmospheric Research wouldn’t explain how they adjust the data for site changes. That is simply untrue, another lie by the so called 'sceptics' in pushing their own agenda.

If you look deeper JBowyer, it's all there for you and anyone to see – but most people don't, they believe what they want to believe, regardless of the facts.

As to the 'Lord Chris', I have better things to do.

Thank you Q & A but I am still unsatisfied but you go and worry about "better things". My challenge is still unmet, lets see who has the time to address why there is an argument about the facts?

JBowyer,

The estimated global temperature, averaged over the Earth's surface, has indeed been higher this decade, averaged over the decade, than in past decades.

The global spatial average (i.e. the average over the surface) has nevertheless not increased since about 2005. This is seized upon by sceptics as "proof" that there is no global warming, but we know the temperature does not always increase, because it slowed in the 1980s and again in the 1990s, only to resume its upward climb. You can see all this more clearly in plots at my blog
http://betternature.wordpress.com/2009/10/15/global-cooling-since-1998/

The reason for the recent slowdown is that there are other influences on temperature, such as the el Nino cycle. There was a strong el Nino (warming) in 1998 and a la Nina (cooling) in 2007-8, which worked against the main warming trend. Heat from the sun has also declined a bit over this period. As la Nina eases off and as the next el Nino comes on we can expect warming to resume.

The average temperature over the Earth's surface is not simple to estimate, because it is not measured everywhere, especially over oceans, in the southern hemisphere, and over the poles. Therefore people have to make sure the averages aren't biassed by the many measurements in places like Europe and North America. Care also has to be taken that each of the thousands of measurement places is not locally biassed. There is thus some acknowledged uncertainty in the final estimates. Sceptics love to claim this means they can't be believed, or that data have been "tampered" with (as in NZ), etc etc, but they overstate the problems.

Reading Geoff Davies post certainly show the arrogance of those who claimed the 'science' is settled.

JBowyer, re the confusion between heating and cooling, 1998 was the hottest year on record. So all other years are not as hot, or 'cooler'. The long term temperature trend is rising, and if you take any year but 1998 as your start date, there is warming. Unsurprisingly, if you take the hottest year on record as your start date, subsequent years are less hot so can be argued to show evidence of 'cooling'. However, climate is measured over 30+ year periods, so the best that the 1998 date can actually do to support AGW skeptics is show that the weather has not been quite so hot since 1998.

Candid, Geoff thanks for your explanations.

Geoff "There is thus some acknowledged uncertainty in the final estimates. Sceptics love to claim this means they can't be believed"

Then why is the uncertainty never admitted, this is the first I have seen from anyone on the AGW believer side that there is doubt about the measurements - usually they are defended feriously. That's what concerns a lot of skeptics, the lack of openness and the defence to the death in the face of what many of us see is reality.

It's a bit like Robin Williams defence of his 100 meter sea level rise " you have to exagerate to get people's attention" which he bitterly admitted on Triple J.

candide, we all accept that the world has been warming continuously since the last ice age, not a problem. The issue a lot of skeptics have is whether mankind is contributing, and how much, or whether man's contribution is trivial int he scheme of things. Another worry for some skeptics is the claim that man can control climate by tweaking this gas by that much in such a time as to effect this result - that just reeks of fantasy.

Prophesizing is a poor art form whatever your field, but for some reason climate science has attempted to ride the warming trend, happily predicting they know exactly what's going on, right up until it flattened out a bit and they can't explain it - then they try to adjust things so they look like they are still on top of it.

It smacks of cover up and deceipt - but that' just my opinion.