The IPCC is the UN body that has investigated this has concluded that it is 90+% likely that Climate Change is caused by man made activity. This is signed by over 2200 scientists. Clearly the theory of Global warming is now beocming the orthodoxy.

If any of the guys on that show could really do any damage to that theory then I guess they could get a Noble Prise.

They reminded me of creationists who try and find one small problem with evolution or an area of differeance between evolutionist and try and bring the whole theory down based on that.

There will be bits we dont understand and models are just that models. But I know that the insurance companies and LLoyds of London believe it is happening and is the biggest Global threat. When cold hearted acturies believe some thing we all should, as they put their money where thier mouths are.

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Stuart

As I see it, the facts - such as they are - are like this:

1) We can't control the climate

2) We can control our use of resources

3) We only have one planet

To me it makes sense to get my water heated up by the Sun - it's 30p/litre if I want to burn oil to do the same job, and I want to use that oil to warm my house up in the winter time instead.

If the Sun's output is presently increasing (and the evidence seems to be there that it really is), then there's a whole lot of nothing we can do about the cause.

But it's not like this is new, the Sun's been doing what it does since way before we modern humans got concerned about it - no wonder there are so many ancient solar worship religions.

The only thing that's different now is that the impact of any catastrophic climate change event will be global mass-migration, population unrest and economic collapse and the politicians are finally waking up to the fact that whoever's holding the baby when it all kicks off is going to be in for a hell of a rough ride.

On a more local scale, one spring storm big enough to send a tidal surge up the Thamas that the barrier can't cope with and London's underwater.

What do you do when a couple of million UK citizens are displaced and the seat of Government and the UK economy plus all its infrastructure is flooded out, overnight?

Unless we remove our dependence on fossil fuels for energy, the only logical end result is that we will eventually use them all up. It took something like 500 million years (give or take) to create those resources in the first place and without them we wouldn't have a technological society at all.

*Irrespective* of whether the CO₂ released in their burning is the cause of global warming, the bigger picture is fundamentally that we either strip the planet bare of energy dense, readily usable fuel or we don't.

If we do, we condemn our species to being forever earthbound - ultimately in a non-technological society fighting it out tooth and claw with the rest of Nature just like we did hundreds of thousands of years ago.

Some would say that might not be such a bad thing.

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Simon

But I think in the long run Channel 4 will regret the programme as irresponsible. Already those taking part are expressing their concerns. It was just a classic bit of conspiracy/ junk science to get an audiance.

For example the story in the Independant this Sunday I quote:

Professor Wunsch said: "I am angry because they completely misrepresented me. My views were distorted by the context in which they placed them. I was misled as to what it was going to be about. I was told about six months ago that this was to be a programme about how complicated it is to understand what is going on. If they had told me even the title of the programme, I would have absolutely refused to be on it. I am the one who has been swindled."

When told what the commission had found, he said: "That is what happened to me." He said he believes it is "an almost inescapable conclusion" that "if man adds excess CO2 to the atmosphere, the climate will warm".

He went on: "The movie was terrible propaganda. It is characteristic of propaganda that you take an area where there is legitimate dispute and you claim straight out that people who disagree with you are swindlers. That is what the film does in any area where some things are subject to argument."

See http://news.independent.co.uk/environment/climate_change/article2347526.ece
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Stuart

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Simon

Did they acknowledge that one could have man-made and natural warming factors working at the same time?
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Stuart

It then went on to argue that CO2 levels historically had lagged temperature rises by around 800 years whereas solar activity correlated exactly - indicating that increased CO2 was an effect rather than a cause of global warming.

Where I started to get annoyed was at the lack of discussion about positive feedback systems and unstable equilibrium, and also at the glossing over of the idea that you might not need huge proportions of CO2 to tip the balance.

"Its small, therefore it doesn't matter" - no, no, no! Or at least, not necessarily.

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Simon

We must also remeber that Co2 is only one the gases we produce. The worlds vast herd of cattle and sheep account for 25% of warming through the methane they produce.

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Stuart

Oh, and 'large stores' means approx 10,000 gigatons of carbon. The atmosphere's currently got about 730 gigatons of carbon in it. Not that all of the methane hydrate would end up in the atmosphere of course - a proportion of it'd react with the sea water as it bubbled up.

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Simon

See http://www.guardian.co.uk/commentisfree/story/0,,2032575,00.html
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Stuart

There's a lag between temperature rise and CO2 levels in the historic record - but what are the error bars on this data? Is 800 years actually resolvable?

There's a correlation between solar variability and temperature - but the mechanism by which this might work is not understood.

This is where the scientific method should shine at its best - ie theories that predict future observations should be taken as good models of reality right up until the killer piece of data arrives that proves them wrong.

Problem is, we don't have another half dozen Earths on which to perform control experiments - so we're stuck with our live experiment on the one we've got now, which seems to amount to:

"Let's use up all our ancient resources in the space of a few hundred years from the start of the industrial revolution and see if anything breaks".

All this squabbling about the cause of global warming is doing no good at all - and it's a red herring. In the 1970s the debate was about global cooling and the prospect of another ice age. The real problem is the inevitable consequence of our insatiable appetite for using up non-renewable resources.

There's a nicely cross-referenced set of articles (and extensive bibliography of scientific papers) on the whole topic of global warming here which gives a useful timeline of how thinking has evolved since the 19th century. See the article on the greenhouse effect theory specifically.

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Simon

I have specific thoughts on what they said that I am surprised George Monbiot dosent address in his Guardian article. The central tennant of the show was why after the war did we have a great increase in CO2 emmissions but a cooling to the 60s. Two things immediatly jump to mind. 1 Global dimming. This is a vital aspect that we are only now starting to factor and this is the effects of the soot and dust particles we produce. These have a very powerful cooling effect. With the introduction of clean air acts in the 60s the amount of soot and smog that the west produced dropped away. After this we had marked warming. Another factor is that there was an agreed reduction in Solar activity 1940-60 that would have also cooled the earth. But since the 60s the Sun activty has not markedly increased but tempreture has.
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Stuart

Some interesting figures on the empirical evidence for this being a major factor are on Wikipedia, the most recent data being from the grounding of all US aircraft in the wake of 9/11, after which the daily temperature range was seen to increase.

I also went looking for data on reductions in solar activity 1940-60, but can't come up with anything concrete - most of the stuff I've found says solar activity increased from 1900 - 1960, but has remained steady since the 70s.

The Met Office has a useful FAQ on climate change, by the way.
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Simon

An interesting point on the effects of the vapour trails from planes. During the day they cool the earth, but at night the vapour trails that form clouds keep the warmth in, and warm the earth. A good arguement against incresed night flights.

Secondly on your point about the lag between warming an CO2 in the historical record. I wouldnt assume that CO2 was the driver for longterm historical tempreture trends. Far more solar activity pitch of the earth and other things. This is the hockey stick graph only works when you add in man made released Co2, and it leads to a corresponding tempreture spike. See the MET office site you linked to.

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Stuart

http://cdiac.esd.ornl.gov/trends/co2/vostok.htm

I note from the abstract that it's apparently not always lagging the temperature rise, sometimes it's in phase.

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Simon

In the past CO2 didnt tempreture drive changes other factors did.

The core samples show co2 fluctuations before man made release of between 191 and 294 ppm.

We have since industrialisation released enough so we are now at 390ppm. It the extra man released stuff that has started to make it drive and force warming. This is what the hockey stick graph shows. We have warmed the planet very quickly by releasing and extra third of world total CO2.

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Stuart

I guess I'm going to have to try and get my head round the complexities of the various climate models and their known strengths and flaws.

I can see why the anti-anthropogenic brigade might distrust certain aspects of the research - the report dealing with reconciling the issue around the apparent lack of tropospheric warming (http://www.climatescience.gov/Library/sap/sap1-1/finalreport/default.htm) is honest about the fact that the satellite and radiosonde data have had to be corrected in various ways.

Those ways are described, and the reasoning appears to me to be justifiable but in another life I could see myself putting phrases like 'corrected in various ways' in sarcastically-applied inverted commas.

Here's the first paragraph of the abstract of the report's Exec Summary:

Previously reported discrepancies between the amount of warming near the surface and higher in the atmosphere have been used to challenge the reliability of climate models and the reality of human- induced global warming. Specifically, surface data showed substantial global-average warming, while early versions of satellite and radiosonde data showed little or no warming above the surface. This significant discrepancy no longer exists because errors in the satellite and radiosonde data have been identified and corrected. New data sets have also been developed that do not show such discrepancies.

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Simon

http://news.independent.co.uk/environment/climate_change/article2355956.ece

They do make the clean air point I thought about yesterday that has pleased me alot.
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Stuart

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Simon

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Stuart

I wish programs like this were made differently - one way would be to allow one side to put a specific point and present its evidence in one segment, then have the other side be shown that segment and allowed to make their own segment refuting it, followed by a rebuttal segment by the first side again. 5 minutes per segment, two issues per half hour programme.

Thing is, I bet there are honest objections to the current models and this program has failed to give any insight into what those objections might really be.

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Simon

http://www.timesonline.co.uk/tol/news/uk/science/article1517515.ece
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Stuart