Wednesday, September 12, 2007

Evidence please, says the skeptic

"Evidence is all," said the skeptic. "So tell me," he said, staring at the pellucid liquid in his ice cold martini, "given that there's been no warming now for nearly a decade, what do you suggest are the four strongest pieces of evidence supporting your hypothesis of man-made global warming? And what are the four strongest pieces of evidence that any warming, whether man-made or natural, would be catastrophic?"

What's your answer? Keep it brief.

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14 Comments:

Blogger Elijah Lineberry said...

Four pieces of 'evidence' of Global Warming...

1. Al Gore said so.
2. He invented the Internet (so there!)
3. He won an Oscar.
4. Billions of people believe him.

9/12/2007 02:02:00 pm  
Anonymous DenMT said...

Your opener, that 'there's been no warming now for nearly a decade' is entirely disingenuous for reasons that I'll more than happily expand on, but for the sake of brevity:

- Arctic sea ice melt: All over the media recently - ice melt in the Arctic has reached record levels. Whilst some might get excited over cheaper freight via the soon-to-be accessible Northwest Passage, various communities and wildlife depending on the ice may beg to differ...

- Observed temperature rise: Rag on the 'broken hockey-stick' as much as you please, the obvious trending in surface, satellite, and radiosonde measurement can't be ignored save with a fairly large effort of will.

- Permafrost thaw: Again, this is an observed phenomenon making the news regularly at the moment. All the more worrying for some of the nasties that the Russians have tucked away in frozen areas...

- Glacial melt: Although there are a few alternative theories floating about as to how the increase in glacial melt has been occasioned, it's a bit silly to ignore the most seemingly obvious one, especially when the weight of scientific opinion swings in behind climate change as the most likely cause.

As to evidence that warming would be 'catastrophic' - I'm not sure I want to have a stab at it. Your question is too vague - do you mean projected warming under the IPCC 'business-as-usual' scenario and within the next fifty-odd years, or a worst-case scenario at 2100, or what?

Your question is phrased problematically - "what are the four bones I will break if I jump off this ladder?" Which rung are you jumping off? I think you need to define exactly what your threshold for 'dangerous' warming is. If you don't wish to, I will have a crack at it myself.

DenMT

(BTW I look forward to a good discussion on science as opposed to politics in this thread, as it seems that's what you're about here. I found it telling in the 'Oh Drought!' thread that you totally avoided engaging any of the meat in the argument, choosing rather to simply have a crack at Al Gore and Tim Flannery. Ball not the man!)

9/12/2007 02:13:00 pm  
Anonymous Anonymous said...

In the spirit of the first post.

1. Peter said so.
2. Lindsay said so.
3. Lindsay and Peter use big words.
4. If you disagree, you are a giant softcock.

9/12/2007 02:18:00 pm  
Anonymous DenMT said...

Elijah and Anonymous obligingly characterise everything that is wrong with the whole climate change debate. Boo.

DenMT

9/12/2007 02:28:00 pm  
Anonymous Jack Ryan said...

Denmt, most of your points are around observations not evidence. Its easy to observe something and claim that it is caused by x event, but to prove that x event caused it requires evidence.

The hockey stick graph suggest that the temperature above an arbitrary zero point in the last few decades. I don't see where the graph states that the temperature is only the effect of humans. If you use the same methods, by proxy, and extrapolate back then temperature variations do occur.

On Earth, the major greenhouse gases are water vapor, which causes about 36–70% of the greenhouse effect (not including clouds); carbon dioxide (CO2), which causes 9–26%; methane (CH4), which causes 4–9%; and ozone, which causes 3–7% (wikipedia)

There has been a 18% increase in atmospheric CO2 in the last 40 years (310-380 ppm wikipedia)

Actual affect on greenhouse effect 20% of 20% = 4% A huge effect on the 80% increase in temperature over the same period (-.2 to 0.6 wikipedia) don't you think?

The greatest tragedy in all this is the knee jerk reaction on biofuels. On average it costs more energy to generate a gallon of corn ethanol (131,000 BTU) than it provides (77,000 BTU). Also add in the increase in food costs, more intensive farming, government subsidies.

9/12/2007 03:11:00 pm  
Anonymous Lgm said...

Jack

DenMT has been asked for proofs on previous occasions. He always fails to come up with any. In the end what he has is a nasty little blind faith, a religion. And that religion is all about forcing other people to do what he wants, regardles of their choices.

LGM

9/12/2007 06:49:00 pm  
Anonymous whatever said...

The position being taken by the faux intellectuals on this site is just as pointless as the dreadlocked anti-capitalist knee jerk squad.

Each side looks at the given evidence and draws conclusions completely congruent with their political & philosophical beliefs, one side wants to shutdown civilization, the other just completely disregards the situation as fantasy.

Both approaches are utterly unhelpful & pointless.

9/13/2007 10:00:00 am  
Anonymous Warming alarmist said...

Jack Ryan, you have to observe in order to collect evidence. Empirical evidence is observed evidence. How do you think scientists collect data? Through magic? Oh, and blindly spouting the 'correlation is not causation' catchphrase is not an argument and only demonstrates that “a little knowledge is a dangerous thing”.

Would you think it reasonable for me to dismiss the idea that the earth revolves around the sun, simply on that grounds that this theory is just based on observation and that correlation does not imply causation?

You say "the major greenhouse gases are water vapour, which causes about 36–70% of the greenhouse effect".

This is true, and with every small increase in global temperature, the amount of water vapour that the air can hold, increases. That in turn increases the temperature, which in turn increases the ability for the air to hold water. Dismissing global warming on the grounds that water vapour is the main greenhouse gas, is just silly. That's like saying "smoking isn't bad for you, because most people die of heart disease".

LGM, you can't prove things in science, so asking for proof is evidence that you simply don't understand how science works.

Denmt was spot-on with his answer. NotPC asked for evidence, and Denmt provided it. If you can refute his evidence, go for it. But don’t try to twist the scientific method into something that it isn’t, simply because to don’t understand it. I also agree with Denmt that the whole global warming ‘debate’ is rife with opinions that have absolutely nothing to do with science. From both sides of the ‘debate’.

9/13/2007 01:00:00 pm  
Anonymous DenMT said...

Jack Ryan: I take your point. The real problem though is that 'proof' of causation - actual concrete attribution - may simply be impossible. The real question, I think is setting an acceptable standard of probability for action.

I think the physical effects that we are now seeing in the world are fairly disturbing, and I find the scientific logic behind the mainstream climate-change causation to be persuasive. I'm not sure that insisting on 100% proof of causation is feasible, because I don't think we are going to get anywhere close to it in the near future.

Do you believe that we are sufficiently scientifically advanced to succesfully attribute these phenomena beyond doubt to a particular cause? I personally don't, but I largely accept the correlations made by scientists.

I agree with your stance on biofuels, but rather than roll out the current science on a large scale, I think further refinement and research might produce a more palatable result. Perhaps more use of industrial by-products, or a whole different way of thinking (the algae research currently being undertaken on behalf of AirNZ?) might be the way.

DenMT

9/13/2007 01:09:00 pm  
Anonymous Jack Ryan said...

Warming alarmist, earth revolving around the sun. Seems quite simple and as you suggest only a fool would discount it. I never said that this was not the case. But it has taken about 10,000 years to come up with a general theory of relativity. This theory tries to explain more than just the earth going round the sun, it has to explain gravitational waves, light waves, times delays, signulaties, etc. It uses a mathematical framework to describe the modes and actions of gravity. Anyway all you are saying is that cause some observations-cause phenomena seem correct than all are. That's fine, you are welcome to your scientific approach. But don't you think that something as complex as the earth ecosystem might not be as simple as you say it is? All you are saying is that I am twisting science. The observations denmt provided have occurred in the past on earth. That is a fact, there is no proof that what is happened now is only a function of humans.

Denmt, I agree that it is hard to prove or disprove the theory of human derived global warming.

Is it better to do nothing, something or all humanly possible to cut CO2 emissions. The cost may be more than the world can handle, leading to a worse situation.

Algal fatty acid esters (bio-diesel) can not be produced at the scale required. We don't have enough space for large scale open air (low productivity) ponds for alga. Whey ethanol is cost efficient, and if they could use geothermal energy for the distillation then they should come out on top. Animal fatty acid esters are available and cost efficient, but there are only so many cows and pigs to butcher.

I am a scientist (I am sure warming alarmist will comment on this!) who is still trying to interpret the data provided. I would love to see some evidence that shows human caused global warming. Though all I see are temperature trends and physical observations that have been repeated throughout the centuries.

9/13/2007 01:39:00 pm  
Anonymous LGM said...

Warming alarmist

Well, if you can't ask for proof then science is not possible.

If there is no requirement to satisfy the demand for proof, then any and all assertions stand simply because they are asserted. An assertion must be accepted at face value. There is no way to test for validity according to your scheme. I guess you must believe in fairies.


But, tell you what. Here's my assertion. You bash small children and steal their toys. Now by your standards I am not required to prove this assertion. It must be accepted. You bully, you.

LGM

9/13/2007 05:11:00 pm  
Anonymous DenMT said...

Jack Ryan: You have picked up the central issue for a lot of people here:

"Is it better to do nothing, something or all humanly possible to cut CO2 emissions[?]"

The question I would ask is, do you think it is reasonable to delay response until such time as 100% proof for causation is achieved (given the extreme difficulty/unlikelihood of getting this).

Super-interesting to read your obviously informed take on biofuels as well - I know there are plenty of issues around energy cost and resource availability for biofuel, and have never really seen them as the 'silver bullet' they are sometimes vaunted as. Now inspired to go and do some more reading!

DenMT

9/13/2007 05:33:00 pm  
Anonymous Jack Ryan said...

Humans are selfish, that is how we have developed our current civilisation and how we got to where we are today. It is very hard to change the modus operandi of such a large number of groups without showing that there is a benefit to operate a different way. I think it is essential that a consensus is reach that either gets us to 100% confidence, or even 85%, if possible either for or against. Once we have proof then even the most ardent critic doesn't stand against logic.

I assume you have seen the energy efficiency and conservation authority website. I went to the 2007 conference and found it very interesting.
If you want an industry overview on the various approaches look at

http://www.eeca.govt.nz/renewable-energy/biofuels/biofuels-conference-07.html

The Scion work on converting wood wast into a fermentable carbon source for ethanol is very important work for NZ.

9/13/2007 08:20:00 pm  
Anonymous Jack Ryan said...

URL didn''t fit.......

http://www.eeca.govt.nz/

renewable-energy/biofuels/

biofuels-conference-07.html

9/13/2007 08:21:00 pm  

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