Have a look at these two plots of UAH data + linear regression:
The last 120 months show a positive trend,
http://www.woodfortrees.org/plot/uah/last:120/mean:12/plot/uah/last:120/trend
The last 100 a negative:
http://www.woodfortrees.org/plot/uah/last:100/mean:12/plot/uah/last:100/trend

Does that mean that the trend suddenly reversed?
Of course not. But it makes it obvious that there is no point in looking at such short term intervals. The noise is too large to see a statistically meaningful signal.

Tamas Calderwood :

And I think we can categorically state that NASA GISS and the CRU HadCRUT data have been adjusted to suit the views of the global warming alarmists. The leaked emails and particularly the leaked computer code from CRU confirm this. That is why I only trust the satellite data.
This is turning into the biggest scientific scandal in history Matt. I am outraged that we have been lied to like this. Why aren’t you?

Can you provide some evidence for this please? I’ve seen nothing that would support this point of view.
My outrage goes towards those that take quotes out of context and use this to dream up some conspiracy, just so that they don’t have to have an actual fact-based discussion.

D.

Um, so how is the 0.38C warming trend over the past 30 years consistent with your claim of 0.2C warming per decade?

And by the way, none of the models expected the world to stop warming this decade. And it has stopped warming. No matter what you say you cannot get around that fact.

I have done a linear regression on the UAH data, again, and here is what the trend is from October 2009 back to October in the following years:

2006 -0.11
2005 -0.16
2004 -0.20
2003 -0.14
2002 -0.13
2001 -0.15
2000 -0.07
1999 0.05
1998 0.11
1997 -0.04
1996 0.04
1995 0.12

Those trends are basically flat or negative all the way back to the mid 1990′s. How can that be when we’ve had record human CO2 production since then?

And I think we can categorically state that NASA GISS and the CRU HadCRUT data have been adjusted to suit the views of the global warming alarmists. The leaked emails and particularly the leaked computer code from CRU confirm this. That is why I only trust the satellite data.

This is turning into the biggest scientific scandal in history Matt. I am outraged that we have been lied to like this. Why aren’t you?

“As for the “shameless manipulation of data, cherry picking and trumpeting of outright falsehoods”, well I say that is the definition of how the global warming alarmists act.

They erased the medieval warm period and now the CRU leaks show how.

They stopped others from being published in the peer-reviewed literature.

They have refused to release their data in an outrageous breach of the protocols of openess in science.

Yet you say what has been revealed is damning of the sceptics? How do you come to that conclusion?”

These accusations have not been denied even by the CRU scientists.

Personally let me say i am all for looking after the environment. I agree we need to do something even god forbid a carbon trading scheme. But this whole thing stinks of a deeper political agenda of which I have a few crack pot theories. For one carbon tax is a ridiculous name, we are all carbon based life forms so are we trying to tax humanity??? and have a look at where the majority of carbon comes from….you will find that interesting. For starters it should be a pollution tax or scheme, and alternative energy investment. NOT because of global warming but rather due to the fact we have to cut down our living standards and learn to share the earths recources. Even if we went all green and on solar panels etc there is only a certain amount of raw material available etc. So in actual fact we need to live simpler lives, maybe only one car instead of two…oh no i said it hahah why dont people do that …that would cut down our pollution levels etc. or even not have lights on after dark lol no more need for power stations…i am being hypothetical but i am right. Why don’t we all be more generous to begin with. Because we are all selfish bastards and we think we cant do anything…so that actual problem is humanity itself…mmm wonder who else says that…look up the club of rome and find there data files. Anyway bottom line is if you, matt and tamas decided to put our money towards making an orphange in our life time we def could. There would be sacrifices but thats what you may have to do to see maybe up to 1000 kids live. So in reality we dont want to change because the issue is one that goes back to our own selfishness…..in reality a carbon trading scheme is may help a little in the planet sharing resources if it is done in the right way but in actual truth the problem is us…so whos up for stuff buying a house and build an orpanage to save 1000 kids, or selling there car and walking or not turning off there lights at night and etc….oh not you thought so…we are all hypocrites.

Secondly this smell of a huge political grasp for power. This will be the first global ets or tax whatever you want to call it. Lets put it out there, its gonna happen. But who wants the power and why??? ill leave that for you to think about and maybe research into a bit. Also look at Rudds scheme, who sets the value of life itself(carbon) is it fairt tale rudd or is it the UN or some other body….that is the question we all should be asking… as aussies.

I already took statistics at university

…and…

I agree that the cooling trend from 1998 is not statistically significant given the variability in the temperature record. However it is still a cooling trend

Before we get to the other issues you raise, please read Riddle me this … and then tell me where your statistical argument is for selecting a 1998 starting point (in other words, arbitrarily removing the data before 1998).

Matt – Thanks for your suggestion but I already took statistics at university and there is no need to be rude.

I agree that the cooling trend from 1998 is not statistically significant given the variability in the temperature record. However it is still a cooling trend and it raises the following questions:

Why was the 1998 El Nino peak so warm?

Why have subsequent El Nino’s not been as warm. As Kevin Trenberth asks in his leaked emails “Where did the heat go?”

I also think you underestimate the effect that the leaked emails and data will have on this debate. There is no denying that it is now big news and people are asking a lot of questions about the way this “science” is conducted. It also shows the appalling state of the CRU’s temperature records – those records that they haven’t deleted.

You refer to the “big picture of the evidence”. Well, CRU is half of this big picture (NASA GISS is the other half) and CRU has been shown to be dodgy.

As for the “shameless manipulation of data, cherry picking and trumpeting of outright falsehoods”, well I say that is the definition of how the global warming alarmists act.

They erased the medieval warm period and now the CRU leaks show how.

They stopped others from being published in the peer-reviewed literature.

They have refused to release their data in an outrageous breach of the protocols of openess in science.

Yet you say what has been revealed is damning of the sceptics? How do you come to that conclusion?

That’s why Phil Jones says “it isn’t statistically significant”.

I quote from my previous post (since you didn’t seem to understand the point):

To illustrate the statistical point, see the recent blind test by Associated Press: “The AP sent expert statisticians NOAA’s year-to-year ground temperature changes over 130 years and the 30 years of satellite-measured temperatures preferred by skeptics and gathered by scientists at the University of Alabama in Huntsville.

Statisticians who analyzed the data found a distinct decades-long upward trend in the numbers, but could not find a significant drop in the past 10 years in either data set. The ups and downs during the last decade repeat random variability in data as far back as 1880.”

Want to understand the big picture of the temperature trend? Here’s your reading for the next ten minutes: Riddle Me This.

The disinformation around the stolen CRU emails is damning, yes – damning of the willingness of climate deniers to focus on cherry-picked quotes, while completely failing to understand the scientific basis for the discussion, and in general ignoring the big picture of the evidence.

In fact, the only substantial indication of scientific fraud to come to light in the stolen CRU emails is on the part of anti-AGW favourites Willie Soon, Sallie Baliunas and Chris de Freitas.

Given the pervasive and shameless manipulation of data, cherry picking and trumpeting of outright falsehoods which we’ve seen from climate deniers over the years, the CRU affair would be pretty damn funny – if the consequences of delay and inaction were not so serious.

For a touch of sanity on all this, I recommend What happened to the evidence for man-made global warming?

– on the aerosols I have a very good source (recently revealed from the CRU emails).

Here is Mike McCraken writing to Phil Jones, head of the CRU:

“Your prediction for 2009 is very interesting…and I would expect the analysis you have done is correct. But, I have one nagging question, and that is how much SO2/sulfate is being generated by the rising emissions from China and India…. While I understand there are efforts to get much better inventories of CO2 emissions from these nations, when I asked a US EPA representative if their efforts were going to also inventory SO2 emissions (amount and height of emission), I was told they were not. So, it seems, the scientific uncertainty generated by not having good data from the mid-20th century is going to be repeated in the early 21st century ”

Pretty interesting.

Now, on the lack of warmth since 1998. Here’s Tim Flannery: “We’re dealing with an incomplete understanding of the way the earth system works… When we come to the last few years when we haven’t seen a continuation of that (warming) trend we don’t understand all of the factors that create earth’s climate…So when the computer modelling and the real world data disagree you’ve got a very interesting problem… Sure for the last 10 years we’ve gone through a slight cooling trend.”

And Phil Jones way back in 2005: ““The scientific community would come down on me in no uncertain terms if I said the world had cooled from 1998. OK it has but it is only seven years of data and it isn’t statistically significant”.

Well, it is now almost 2010 and we’ve had nearly 12 years of cooling since 1998. At what point can we say the cooling is significant?

These CRU emails and data are pretty damning mate. Why are these guys suppressing dissent, deleting data, questioning the lack of warming and admitting they don’t know what’s happening in the climate system, while at the same time they are ramping up the fear-factor?

Even George Monbiot now agrees this is all “a major blow”.

What do you think?

the stuff about aerosols cooling the earth vs greenhouse gases warming it is pure conjecture. There is no actual evidence that this is what caused the temperature fluctuations.

Where do you get that impression from? There is historical data on tropospheric aerosols, in fact, which can be combined with basic physics to arrive at quite a good estimate of the associated forcings over the last century. Clearly it’s not completely precise, but the level of confidence is quite good on this aspect – hardly “pure conjecture”. See this NASA page for some details on the tropospheric aerosol data. There’s plenty more technical information on this if you dig for it.

Also, 2001 – present is not a short time frame. The AGW theory says more CO2=more warmth. Well, we’ve got more CO2 so where is the warming? What has been cooling the earth for the past ~10 years?

This really is one of the top denial memes, and one that I’m afraid I’ve found deniers to absolutely refuse to understand.

Short answer: as a global system, the planet has indeed continued to warm over this period; and the surface atmospheric temperature is only a tiny part of this energy flow, and is subject to a whole lot of natural fluctuation. You say the period since 2001 is “not a short time frame” – based on what? This is not a seat-of-the-pants thing; there are good statistical reasons for needing a longer time frame than one decade for data with a level of short term variation like the global temperature record. This is why a common definition of the word “climate” is “the average of the weather over at least 30 years”.

To illustrate the statistical point, see the recent blind test by Associated Press: “The AP sent expert statisticians NOAA’s year-to-year ground temperature changes over 130 years and the 30 years of satellite-measured temperatures preferred by skeptics and gathered by scientists at the University of Alabama in Huntsville.

Statisticians who analyzed the data found a distinct decades-long upward trend in the numbers, but could not find a significant drop in the past 10 years in either data set. The ups and downs during the last decade repeat random variability in data as far back as 1880.”

Please re-read the last four paragraphs of my most recent comment in this thread, and especially the articles I link to in them, as you appear not to have understood this material yet.

I keep coming back to this but if we can’t explain past variability (Roman warming, medieval warming, dark ages, little ice age, etc) how can we now suddenly say the tiny amount of warming over the past 100 years is because of man-made CO2?

Erm… because that’s what a large body of evidence indicates. Perhaps reading this will help.

not a single person has died because of global warming.

Big claim. How exactly do you reconcile that against the 35,000 that died in the 2003 European heatwave, the thousands that died in the 2006 European heatwave, and indeed the horror of Darfur, of which a major cause is the water crisis there, linked to the rise in temperatures in the Indian Ocean?

Surely in this world with billions living in poverty we have more pressing priorities.

The worst impacts of climate change over this century are expected to be in poor countries, particularly in Africa. Darfur is, if anything, likely to be repeated many times over in sub-Saharan Africa. To ignore those impacts – particularly given the very strong scientific body of evidence which underlies those projections – would be an act of spectacular callousness.

Please excuse me if my postings are light in the next week or two. Work is damn busy.

Likewise… apologies for the delay in replying.