Sunday, September 7, 2008

Let's discuss the weather

Wondering your opinion, not particularly trying to change it:

1. How likely is our avoiding dangerous climate change by getting enough international cooperation to cut global carbon emissions enough in time?

2. How much of a difference can I make to this?

3. If the chances in 1. are small, why don't we try something like geoengineering?

4. If 1 and 2 are small and 3 feasible  (so the world isn't about to end), why is cutting emissions an important issue to work on? (given the opportunity costs: there are lots of other critical issues)


denis bider said...

First off, note that public perception of global warming (mine and yours included) is being corrupted by distortions and exaggerations.

Yes, the 2007 IPCC consensus was that there's a 90% probability that humans are responsible for a major part of the 0.5 C warming over the past 50 years.

But the consequences will not necessarily be disastrous.

For example, people point to the melting Antarctica and say: "Look, global warming!"

And if Antarctica would melt, then, well, New York and Holland are certainly screwed, now - aren't they.

Except that - no, a melting Antarctica doesn't meet the predictions of the models for global warming.

If the world is in fact warming, the models say, this should cause more evaporation from the oceans, which should cause more snowfall over the Antarctic, which should cause more ice there, because most of the Antarctic will still permanently stay below zero, even with higher temperatures everywhere else.

Then there's the graph that shows near-exact correlation between CO2 and temperature throughout history. People assume from that graph that CO2 causes high temperature. But it's the other way around. In the natural course of things, CO2 lags behind temperature by about 800 years. The reason atmospheric CO2 varies with temperature is that it is less soluble in ocean water when temperatures are higher, so it evaporates, and there is more of it in the atmosphere. It doesn't work the other way around.

Then there's the idea that there have been more hurricanes in recent years and that global warming is what caused Katrina and flooded New Orleans.

All of that is bollocks. There's no more hurricanes making land fall in the US than there used to be, it's just that we can now monitor maritime weather more easily, so we count a lot more of the hurricanes out in the sea.

And Katrina was a level 3 hurricane when it made landfall, nothing out of the ordinary.

All I'm doing here is basically repeating things from the Global Warming chapter of Richard Muller's Physics for Future Presidents, an excellent books which clears up a lot of other things that "everyone knows that ain't so". I recommend it highly.

Now, a prediction I find credible is that global warming is going to begin showing serious effects in the second half of this century.

If lifetimes remain at an 80-100 average during this time, then this is not something that much concerns me. If some places are eventually going to be flooded, people can adapt by not building new things there. If the flooding is known far enough in advance, the things built there in the past will have already been amortized. The major change will be that a bunch of people are not going to inherit a house or condo they can live in all their lives, when they otherwise would have.

Given this background, to your questions:

1. Can we avoid climate change? No. Coal is by far the cheapest energy source there is. There's good evidence that GDP correlates with energy, so China and India are putting up gigawatts of coal-fueled power plants every week. This is not going to change. Any other fuel source would be way more expensive. Coal-based power plants can be made clean by sequestering the carbon, but this also multiplies the cost of energy, so it's questionable that they're going to consider it. They might, by the time they have a big enough, spoiled middle class with enough idle time on their hands to worry their heads with environmental change. By then, it will be too late.

2. How you can make a difference? Let's see. Nuke China and India. Umm... No. Assassinate their leaders and take power. Umm... No. Threaten war unless they use clean energy. Umm... No. What else is there?

3. Why we don't try geoengineering: how many experiments do you know that behaved exactly as predicted the first time they were tried? Programmers know, from every day experience, how hard it is to find flaws in your logic, until you run your program, and you see actual results. When confronted with a tricky language, say assembler, most beginners take an awful number of attempts before they get it halfway right. Each time before that, the program awfully crashes, while the beginner cries: "Oh, why?!"

4. Cutting emissions is not really an important thing to work on, unless the Chinese and Indians work on it, too.

That said, if they agree to work on it, then cutting emissions is an excellent thing to work on.

And it must all be done in a way that the consumer doesn't even notice, and which doesn't reduce everyone's comfort in the least. Anything else is not conservation, but nagging people for the sake of a "community spirit" and for political points.

denis bider said...

Well, there are other aspects of global warming besides flooding, of course.

For example, shifting weather patterns could make it harder to maintain our food production.

But it doesn't mean the world's about to end.

It might just mean that, with our agricultural capacity halved or worse, meat will become a rarity (a veggie diet is much less resource intensive); or if even feeding the world on a veggie diet doesn't work out, then plant-based food that we consider normal today will become a luxury, while people who are not the most well off will augment their diet with some kind of carbohydrate produced in a factory out of coal.

It's already possible to convert oil to alcohol, and totally safe too, and cheaper than making alcohol out of plants that are more recenlty deceased. Perhaps the cheapness, and the interests of the alcohol industry, are why alcohol-from-oil cannot currently be sold in the US.

Maybe that will change if there are no more vineyards, eh? :-)

Katja Grace said...

Do you have any explanation for why the reality of climate change is invisible to so many reputable climate scientists?

denis bider said...

Which scientists, and what reality, do you mean?