Sunday, December 13, 2009

Getting warmer

How can we know that increases in CO2 cause increases in temperature?

Get three big jars full of air, each containing a thermometer. Jar A is your control. Put it to one side. Add a small amount of CO2 to Jar B. Add 10x the amount of CO2 that you added to Jar B to Jar C.

Carefully irradiate all three jars, using the same amount of radiation and the same time.

One hour later, observe the temperature of the air in all three jars. End of discussion.

That really is it. We discovered the link in 1862. Nothing's changed.

But it might be a really small effect, right? Well, that seems feasible if you never experimented with different levels of CO2, or if small effects don't matter. The lab does not translate well to the atmosphere (the earth is not contained within a bell jar!), but the effect is big enough. And it doesn't have to be huge because it's incremental. Increasing the heat means more heat to radiate away when the sun isn't shining. And a small effect is enough. Think about our hot summers. A sheet is pretty thin but we have nights where sleeping with a sheet over you is unbearable. The analogy is quite close, because what causes the discomfort is that the sheet prevents you from radiating heat away. It only traps a little, but it's enough to make you feel uncomfortably warm.

Now imagine you have to keep yourself wrapped in the sheet, under your normal clothes, during the day.


On that subject, here is an excellent article on the "Climategate" scandal, which is a bit of a case study in how the media can beat up nothing much into something that looks big, fuelling the deniers, who don't require facts at the best of times.


At 1:16 pm, Anonymous Mcleod said...

Shit article. You are Blinkered! read the comments and read the emails

Jones is a cunt deleting data and refusing to make public his methodology simply scream out that noting the man says should be believed.

At 2:45 pm, Anonymous Dr Zen said...

Please moderate your language when commenting on this blog. I'll let it pass this one time but I won't permit further comments with this type of language.

As for the substance of your comment, I've read enough of the emails to get the idea. There's nothing in them to merit the discussion they've raised.

Jones makes his methodology public in the same way as any other scientist: by publishing papers. As for "deleting" data, don't be ridiculous. The data aren't secret.

But as the emails do note, debating with deniers is like playing whack-a-mole. They don't deal in facts, just objections. Just like Holocaust deniers, truthers or creationists. There's no convincing them because their thesis drives their argument, not the facts, whereas us poor rational types are stuck with the facts.

At 2:33 pm, Anonymous Anonymous said...

When did the earth start to warm? Answer 1850s Reason Increased Solar activity/Industrial revolution?(We know for a fact that solar activity increased) Taking Europe as an example prior to the 1300s it was much warmer. From 1300s to 1850s Europe was much colder the canals of Venice would freeze. This all changed suddenly in a 10 year period around 1850. This is all fact its documented. Weather changes naturally, we have a tiny amount of data about mans effect on climate. Yet drastic measures are advocated. The trouble is people like you and the politically lead scientist who make their living from the CO2/GW issues are so closed minded that hey refuse to engage with people that have differing opinions or theories and have gone out of their way to destroy careers and reputations to the point where no other explanation apart from CO2 is being considered. And vast amounts of money will be spent in reducing CO2 when it should be spent in alleviating the effects of GW which is real. We have to adapt to a changing environment because we can not control the atmosphere or the weather and to think we can is absurd.

At 2:38 pm, Anonymous Dr Zen said...

Almost everything in your comment is plain wrong. The "Little Ice Age" is a myth. No climate scientist has had their career "ruined" by disagreeing with the consensus because the consensus is plainly based in fact, and no climate scientist would be at odds with it any more than a biologist would claim that evolution does not happen. The linkage between CO2 and warming is easily shown; that we are emitting CO2 is not controversial. Deniers simply push at the gaps that Exxon pays to find.

BTW, the past decade was the hottest on record but sun activity was below average. Whoops! There goes your hypothesis!

At 1:05 pm, Anonymous Don said...

I appreciate the information you sent and look forward to going through it when I have time. Christmas and factory errors prevent it for the time being.

Meanwhile, not yet being enlightened, I was amused by the article in Scientific American which discusses thawing and releasing of arctic methane, which will multiply many times the effects of human-released CO2, because the claim, evidently presumed, was that it is thawing due to that release. And of course that's possible; but I still get the impression that many scientists, especially those who wish to get published in magazines such as Scientific American, are tending to lead the data with conclusions, and editors and most readers, who are already on board, are letting them do it. It's an interesting phenomenon, whether or not in the right. (BTW I only skimmed the article, will read it soon and see if my concerns are addressed.)

At 1:07 pm, Anonymous Dr Zen said...

I don't really understand your objection. The planet is warming because of CO2 increase. The warmth is melting the ice. Which leads to methane release. Were you not aware that it's the outcomes of warming that worry us, not so much the warming in itself?

Your argument seems to me similar to saying you can't blame a man with a gun for killing his neighbour just because he pulled the trigger that made the gun release a bullet.

At 1:15 pm, Anonymous Don said...

To restate my comment more succinctly:

Arctic methane has the potential to augment CO2-induced warming by 20x to 40x (IIRC). That such a huge factor might be triggered by an effect defined as being much lesser suggests strongly that it might also be triggered by other unidentified causes, and more obviously that Earth's climate is particularly dynamic. A dynamic and little-understood system is surely prone to a misreading.

Guess I have to read it. Tonight, maybe.

I'm getting friendlier to doing something about it anyway. Maybe it's groupthink taking its toll on my skeptical independence, my preference not to believe what everyone else so enjoys believing getting ragged about the edges.

At 1:20 pm, Anonymous Don said...

Were you not aware that it's the outcomes of warming that worry us, not so much the warming in itself?

Of course we should worry, and make plans and contingencies and agreements to work as a global community. But if, as said above,

vast amounts of money will be spent in reducing CO2 when it should be spent in alleviating the effects of GW which is real

then we risk making disastrously misdirected choices.

I haven't any interest in denialism, indeed both my sons are motivated in their burgeoning academic careers to develop the means to reduce Man's CO2 output and I'm fully behind them on that.

At 1:20 pm, Anonymous Dr Zen said...

You understand that a snowball can create an avalanche?

Imagine this: a big room full of sulphuric acid. You have a key to the door. If you unlock and open the door, you will be bathed in sulphuric acid, which isn't nice. Now surely given that the action of the key is so small, it must be that something else could cause the acid to bathe you?

It's not "scepticism" to deny the truth, Don, only to question what it is. The truth in this case is pretty well attested. I'm not a religious type myself, so I assure you I wouldn't credit it if I didn't feel it stood up to scrutiny some.

BTW, on the subject of gaseous release, I suggest you look into "eutrophication" and the possible outcome of breaching the thermocline in deep oceans.

At 1:22 pm, Anonymous Dr Zen said...

I think that we actually need to do both: cut emissions at whatever cost and mitigate global warming. They are not separate issues. However, the latter is not enough without the former, unless you have a magic wand.


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