Tuesday, July 3rd 2012, 1:16 PM EDT
We discussed global warming with well-known sceptic James Delingpole and Andrew Pendleton of Friends of the Earth (FoE) on the Daily Politics (June 22).
One of the great claims of the sceptics is that that global temperatures have not risen in this century and that they probably stopped rising in 1995.
Those who believe in man-made global warming, like FoE, either deny this or think it irrelevant over such a relatively short period of time, when the longer-term trend in temperatures is clearly upwards.
I asked them to send me their respective cases and promised I would post them on my blog for your perusal and debate. Both have kindly done so - and here they are.
Let me make a couple of observations before you get stuck in.
Andrew's case comes first. He offers what he describes as a helpful graph but in fact it is over 120 years so it's not exactly clear what's happened between 1995 and now -- except that there's been a lot of fluctuation in annual temperatures (though all at a high level historically).
He rightly says the long-term is clearly up, though that is made to look more dramatic by choosing a left-hand scale in tenths of a degree. Since 1940 the rise in temperatures looks like it's been around only 0.4 degrees.
James case follows: He now says not that there has necessarily been no warming since 1995 but there has been no statistically significant warming.
But, like Andrew, he doesn't give us a detailed breakdown of temperatures since 1995 from a highly-regarded source for us to study.
One final point before you get stuck in. In a sense they are a bit like ships passing in the night, each making their case but not necessarily engaging with the arguments of the other side.
I might need to ask them to respond to each other's postings. But before I do that, over to you. I look forward to your comments.
Andrew Pendleton: global warming has not stopped
As I made clear on the programme, I'm not a climate scientist. So I consulted some climate scientists and scientific literature from respected institutions - which I'd also read before going on the programme - in writing this piece.
Below is a very helpful graph that combines four of the world's most authoritative data sets on global, average surface temperature: two from the US, one from the UK and one from Japan.
Graph supplied by Friends of the Earth
The data in the graph is important for three reasons.
First: it shows a long term warming trend - and quite a dramatic one - beginning in the early 20th century and, evidently, still underway.
Second: it shows how four separate data sets reach broadly the same conclusion.
And third: it shows how much fluctuation there is from year-to-year and, in fact, from decade-decade.
As Chris Ripley, professor of climate science at UCLA put it to me: "No climate scientist ever stated or expected the global average temperature to rise as a smooth curve. If you look back over the data for the last 100 years rather than just cherry-picking a short [in climate terms] period, the fluctuations are very clearly evident. But so is the upward trend, especially of the last 40 years."
Related to this and having seen the Daily Politics on Friday June 22, Bob Ward at the London School of Economics sent me some very useful, basic number crunching from the team at the Grantham Research Institute on Climate Change and the Environment.
The table in the flog shows in statistical terms what the graph above illustrates what Prof. Ripley says: "warming accelerates and slows, but the long-term trend is clearly upwards".
A further complicating factor is that while the long-term trend is clear, part of the explanation for the fluctuations over the short term is that the energy from the sun is stored in different places - the land, the oceans and the atmosphere.
This energy - which is increasing in overall volume due to the enhanced greenhouse effect caused by human emissions of carbon dioxide and other gases - may not show up as increased surface temperature.
Instead it may be transferred into warming of the ocean's interior where it is hidden from the surface temperature data, the melting of ice caps, or accelerated movement of oceans or atmosphere.
A very good explanation of why we should in fact focus broadly on the growing energy imbalance (i.e. too much of the sun's energy being trapped inside the atmosphere) due to a higher concentration of greenhouse gases rather than narrowly on temperature is contained in this blog.
In a nutshell. the simple answer to the question posed on the programme and to the challenge by Andrew Neil is 'no, global warming has not stopped.'
This is why Friends of the Earth is campaigning for more efficient use of energy across our economy and for a major shift to the harnessing of energy from the sun, sea and wind to reduce emissions of carbon dioxide.
While climate change is Friends of the Earth's main reason for campaigning for renewable and efficient energy, there are many other very sound reasons for investing in renewable energy sources too.
For instance, we have an abundance of natural renewable energy sources in and around the UK and more efficient use of energy will save us and our economy money. See our Clean British Energy campaign for more details.
In particular, what we're calling for in the campaign is for the energy bill' s primary purpose to be the virtual elimination of carbon emissions from electricity generation by 2030.
The massive opportunity for the UK is that a shift to renewable, though requiring investment upfront, promises permanent release from high and increasingly expensive future fossil fuel imports in favour of free fuel from the wind, sea and sun.
James Delingpole: global warming has stopped
"No global warming since 1998." There are few things better calculated to annoy a Greenie than this statement - which is why I like to mention it as often as possible.
They hate it even more when you mention that the arch-warmist Professor Phil Jones of the notorious Climatic Research Unit (home of the Climategate scandal) admitted in a BBC interview that there has been "no statistically significant global warming since 1995".
That's why, if you google it, you'll find so many climate activists falling over themselves to rebut what they consider an outrageous and erroneous claim.
They point out, for example, that by "no statistically significant global warming", Prof Jones means that there still has been warming, just not that you'd notice.
They point out that the trend may have been skewed by unusually strong El Nino events. And they argue that, in any case, 15 years is too short a timescale in which to read a significant trend.
Actually I share their frustration with the "no global warming since 1995/1998" claim, though for very different reasons.
As a point scoring device in the sound-bite driven immediacy of a TV studio debate, it's quite useful.
But as a representation of the key issues in the global warming debate it is grossly misleading.
1. It presupposes that the temperature data sets maintained and quoted by the climate alarmist establishment are reliable and trustworthy. But they're not: they have been subject to "adjustments" by scientists who, as we saw in the Climategate emails, have political motivations and a financial vested interest in exaggerating the extent of "global warming". See for example postthis link In the US, for example, the three hottest years in history according to actual measured thermometer readings all occurred before 1940. Current US temperatures are close to the post-1880 average.
2. It presupposes that there is such a thing in a chaotic system as a "global climate" from which a global mean temperature can be calculated and that it can in any way measurable with any accuracy. The differences in temperature are often by as little as 1/100th of a degree. Phil Jones may be right: it could be going up a teeny weeny bit. Or he could be wrong: it could be going down a teeny weeny bit. We are in the realm, here, of angels dancing on the head of a pin.
3. Funny, isn't it, how most of the significant "anomalous" warming "detected" by NASA in recent years (notably 2010) were in those parts of the world where there are no weather stations?
4. Since 1850 the world has been emerging from the Little Ice Age. Of course decades at the top of that gentle warming trend (of about 0.8 degrees C) are going to be, on average, warmer than those at the bottom.
5. Where - anywhere - is there any real world evidence that any of the recent warming is unprecedented or potentially catastrophic? There is none. Zero. Zilch. Nada. All evidence of catastrophic man made global warming exists only in the febrile imagination of climate "scientists" and the people responsible for their exceedingly dodgy computer projections.
6. What we CAN say is this. AGW theory is predicated on the idea that there is a strong correlation between man-made CO2 output and global warming. But while in the last decade - thanks largely to China - CO2 levels have continued to rise dramatically, world temperatures most definitely have not. This suggests that there are more, many more, things responsible for climate than CO2 levels. Such as - duh - the activity of the sun.
7. Read my book Watermelons: How The Environmentalists Are Killing The Planet, Destroying The Economy And Stealing Your Children's Future (Biteback) It's all in there.
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