Interesting Times - Part I

By BJ

The Climate, it is a-Changing

A number of years ago, my sister asked me if I thought we, as in humanity, would do enough to stop global warming. My answer in short, was no. I said my only real hope was that we�d run out of oil before we burnt too much of it to irreversibly damage the planet.

At the time, I figured it would be mid-century before we had an idea about which would be the case. Instead, it seems the showdown is coming much sooner.

The most visible sign of all this right now is the Arctic sea ice, which hit a record low last summer and is being forecast at about a 60% probability of beating that record this summer.

Arctic sea ice, sometimes billed as Earth's air conditioner for its moderating effects on world climate, will probably shrink to a record low level this year, scientists predicted on Wednesday.

In releasing the forecast, climate researcher Sheldon Drobot of the University of Colorado at Boulder called the changes in Arctic sea ice "one of the more compelling and obvious signs of climate change.

If that prediction holds true, it would be the third time in the past five years that Arctic sea ice retreated to record lows, the scientists said in a statement.

Part of what's happening is that the thick multi-year ice, some of it several thousand years old, is breaking apart and being replaced with thiner, annual ice cover that is more easily melted again the next summer.

The major threat though, is the feedback mechanism of albedo. Sea ice, being a nice bright white, reflects 80% of the sunlight that hits it back into space. Open water absorbs 80%. Less ice, means more sunlight absorbed, means higher ocean temperatures, means even less ice. If the predictions are right and the sea ice cover drops even further this year than last, then it is a good indication that we've passed the tipping point on at least one part of the Climate Change equation.

There are other signs as well, such as islands starting to disappear thanks to rising seas, but the Arctic is referred to as the canary in the coal mine of Climate Change, and the canary is in ill-health.

Of course, the reason for all of this is that we're pumping out carbon dioxide at ever increasing rates and raising it's concentration in the atmosphere to record levels.

The concentration of carbon dioxide in the atmosphere has reached a record high, according to new figures that renew fears that climate change could begin to slide out of control.

Scientists at the Mauna Loa observatory in Hawaii say that CO2 levels in the atmosphere now stand at 387 parts per million (ppm), up almost 40% since the industrial revolution and the highest for at least the last 650,000 years.

The figures, published by the US National Oceanic and Atmospheric Administration (NOAA) on its website, also confirm that carbon dioxide, the chief greenhouse gas, is accumulating in the atmosphere faster than expected. The annual mean growth rate for 2007 was 2.14ppm � the fourth year in the past six to see an annual rise greater than 2ppm. From 1970 to 2000, the concentration rose by about 1.5ppm each year, but since 2000 the annual rise has leapt to an average 2.1ppm.

Now, as stated, part of that increase comes from the fact that we keep pumping CO2 into the atmosphere, but part of it is due to a different, and far more worrisome reason. You see, the world's carbon sinks, like the oceans, aren't soaking up as much carbon as they used to.

The amount of carbon dioxide being absorbed by the world's oceans has reduced, scientists have said.

. . .

Results of their 10-year study in the North Atlantic show CO2 uptake halved between the mid-90s and 2000 to 2005.

. . .

BBC environment analyst Roger Harrabin said: "The researchers don't know if the change is due to climate change or to natural variations.

"But they say it is a tremendous surprise and very worrying because there were grounds for believing that in time the ocean might become 'saturated' with our emissions - unable to soak up any more."

He said that would "leave all our emissions to warm the atmosphere".

Worse for us, if the oceans are hitting their saturation point, things like the bleaching of coral and other pollution caused die-offs could turn the ocean from a carbon sink into a carbon emitter, which truly puts us in dire circumstances.

And because I can't leave well enough alone, that isn't even the worst news. You see, it turns out that in addition to record levels of carbon dioxide, methane levels have been shooting up as well.

Methane, though short-lived in the atmosphere, has about 25 times the heat trapping capability of CO2, so its effects can be felt at far lower concentrations. And it also happens to be the main threat of the other great Climate Change feedback mechanism tied to warming in the Arctic.

You see, there are massive amounts of methane trapped in the Arctic permafrost, ground which by definition is frozen year-round. If, thanks to higher temperatures, the permafrost starts to melt, it releases the heat-trapping methane, which ups the temperature, which melts more permafrost, which releases more methane, and so on.

So what does this all mean for the Earth's climate? Well, as Ron put it a while back, nobody really knows. There are too many variables to be certain what exactly is going to happen. A good example of this is a recent story from the BBC that suggests global warming will actually decrease the number of hurricanes. Such stories are of course followed by the inevitable claims that climate scientists don't know what they're talking about and therefore Climate Change is nothing to worry about. Also predictable is that they've completely missed the point.

You see, the exact change caused by global warming, and even the exact cause of global warming, isn't what we need to be worried about. It's the fact that the climate will become uncertain, and we're not terribly well set up to deal with that.

Over the last several hundred years we have constructed critical infrastructure on the assumption that the climate regime is going to stay more or less constant over time. We�ve done that all over the world, of course, and while there are some technological fixes available to the rich (see the Dutch engineering of their sub-sea level coastal fortifications), more broadly, we�ve got a lot of life, wealth and property invested in the notion that the ocean will stay more or less where it is.

And of course, it isn�t just coastlines we need to worry about. Global warming is not just an issue of sea level rise; it presents, as Postrel does accept, a much broader range of possible consequences.

Climate change affects rainfall, storm severity, longer term patterns of drought and damp and so on. Global agriculture on industrial scales are built on climate assumptions. Land use and distribution reflect generations of dispute and resolution on the question of access to climate resources and so on. Radical change in the climate regime � an expansion of drought areas, shift of rainfall patterns and so on � might not, as Postrel and others have argued, produce a net loss of ecosystem capacity world wide. But such shifts do devastate human constructions built on a set of beliefs about the climate that are no longer true.

Put this another way: Hurricane Katrina was a disaster, but it was not a natural disaster. Rather, it was a natural event � category 3 or 4 hurricanes are going to hit in the western gulf with a certain frequency; that�s just the way that part of the system goes.

What made Katrina a human disaster was the fact that since the last major hurricane came that way, New Orleans in all its modern glory and inadequately engineered levees had grown up in the way. Take that and spread it all over the globe, and you have the reason why modern anthropogenic climate change is scarier than the Little Ice Age was. The broad argument we should do nothing because the climate has always varied fails to take into account this change from then to now.

As it works out, even if Climate Change were a purely natural phenomena, (which only the seriously deluded can believe), it would still be a seriously stupid idea to just sit back and allow it to happen.

That said, as I told my sister several years ago, so long as the oil is flowing freely and cheaply, it's pretty damned unlikely that people are going to actually do anything significant to even try and mitigate the effects.

As luck would have it, oil, among other things, is no longer so cheap or flowing so freely. We'll take that up in Part II.