Frequent readers of TCOE know that whenever I talk about my personal short list of must-read authors, Bill McKibben is always right at the top. Well, he’s at it again, this time with a piece in Mother Jones, The Most Important Number on Earth:
Sooner or later, you have to draw a line. We’ve spent the last 20 years in the opening scenes of what historians will one day call the Global Warming Era—the preamble to the biggest drama that humans have ever staged, the overture that hints at the themes that will follow for centuries to come. But none of the notes have resolved, none of the story lines yet come into clear view. And that’s largely because until recently we didn’t know quite where we were. From the moment in 1988 when a nasa scientist named James Hansen told Congress that burning coal and gas and oil was warming the earth, we’ve struggled to absorb this one truth: The central fact of our economic lives (the ubiquitous fossil fuel that developed the developed world) is wrecking the central fact of our physical lives (the stable climate and sea level on which civilization rests). For a while, and much longer in the US than elsewhere, we battled over whether this was true. But warm year succeeded warm year and that fight began to subside. Instead, the real question became, is this a future peril, the kind of thing you take out a reasonably priced insurance policy to guard against? Or is it the oh-my-lord crisis you drop everything else to deal with? Will Hitler be happy with the Sudetenland, or is the world going to spend every cent it has, not to mention tens of millions of lives, fighting him off? Trouble, or TROUBLE? These last 12 months, we’ve found out.
It was September 2007 that the tide began to turn. Every summer Arctic sea ice melts, and every fall it refreezes. The amount of open water has been steadily increasing for three decades, a percent or two every year—it’s been going at about the pace that the hairline recedes on a middle-aged man. It was worrisome, and scientists said all the summer ice could be gone by 2070 or so, which is an eyeblink in geologic time but an eternity in politician time. In late summer of last year, though, the melt turned into a rout—it was like those stories of people whose hair turns gray overnight. An area the size of Colorado was disappearing every week; the Northwest Passage was staying wide open all September, for the first time in history. Before long the Arctic night mercifully descended and the ice began to refreeze, but scientists were using words like “astounding.” They were recalculating—by one nasa scientist’s estimate the summer Arctic might now be free of ice by 2012. Which in politician years is “beginning of my second term.”
The key phrase, really, was “tipping point.” As in “I’d say we are reaching a tipping point or are past it for the ice. This is a strong indication that there is an amplifying mechanism here.” That’s Pål Prestrud of the Center for International Climate and Environmental Research-Oslo. Or this, from Mark Serreze, of the National Snow and Ice Data Center at the University of Colorado: “When the ice thins to a vulnerable state, the bottom will drop out…I think there is some evidence that we may have reached that tipping point, and the impacts will not be confined to the Arctic region.”
“Tipping point” is not, in this context, an idle buzzword. It means that the physical world is taking over the process that humans began. We poured carbon into the atmosphere, trapping excess heat; that excess heat began to melt ice. When that ice was melted, there was less white up north to reflect the sun’s rays back out to space, and more blue ocean to absorb them. Events began to feed upon themselves. And in the course of the last year, we’ve seen the same thing happening in other systems. In April, the National Oceanic and Atmospheric Administration released a report showing that 2007 had seen a sudden and dramatic surge in the amount of methane, another heat-trapping gas, in the atmosphere. Apparently, one reason is that when we burned all that fossil fuel and began raising the temperature, we also started melting the permafrost—melting eight times more of it in some places over two decades than had thawed for the previous 1,000 years. And as that frozen soil thaws, it releases methane; enough of it now bubbles out to make “hot spots” in lakes and ponds that don’t freeze during the deepest part of the Siberian winter. The more methane, the more heat, the more methane. Wash, rinse, repeat.
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And we have a number—350. The most important number on earth. If the Internet has a cosmic purpose, this could be it—to take that number and spread it everywhere on the planet, so that everyone, even if they knew little else about climate change, understood that it represented a kind of safety, a bulwark against the monsoon turning erratic, the sea rising over their fields, the mosquito spreading up their mountain.
I’m part of a group of people calling ourselves 350.org. Our goal is simple—to try to get people everywhere to spread that number. We’ve started finding musicians and artists, athletes and video makers, and most of all activists, the kinds of people who are working to save watersheds or babies, or to educate girls or to block dams, or any of the other thousand lovely things that won’t happen if we allow the basic physical stability of the planet to come unglued. We need a lot of noise, and we need it fast, in the scant months—14 now—before the world meets in Copenhagen next December to draw up a new climate treaty. Because one clear implication of 350 is that that treaty is our last real chance to get it right. If we don’t, then all we’ll be dealing with is the consequences. Once the ocean really starts to rise, dike building is pretty much the only project.
It’s not clear if a vocal world citizenry will be enough to beat inertia and vested interest. If 350 emerges as the clear bar for success or failure, then the odds of the international community taking effective action increase, though the odds are still long. Still, these are the lines it is our turn to speak. To be human in 2008 is to rise in defense of the planet we have known and the civilization it has spawned.
I’ve quoted just the first and last grafs here. Please go read the whole thing. You can thank me later.
The 350 number is, of course, 350 parts per million of CO2 in the atmosphere. I’ve talked about this number repeatedly on this site, and how James Hansen (also on the must-read list) is convinced it is “the” magic number for CO2 buildup in the atmosphere, even though we’re currently at about 385 ppm and growing. See my post from yesterday, Document alert: Target Atmospheric CO2, for a brief excerpt from the latest paper on the topic from Hansen and his colleagues, plus links to the paper and its supplementary material.
Related posts on the general topic of 350 ppm and this latest work from Hansen, et al.:
- 350.org
- NASA’s James Hansen, et al, on what’s needed to avoid a total ice-melt on Earth
- Stabilize at 350 ppm or risk ice-free planet, warn NASA, Yale, Sheffield, Versailles, Boston et al
Some other items related to the general notion of what we’re doing to the planet, and, therefore, ourselves, by pouring 27 billion tons of CO2 into the air every year:
Southern Ocean close to acid tipping point:
Australian researchers have discovered that the tipping point for ocean acidification caused by human-induced CO2 emissions is much closer than first thought.
Scientists from the University of New South Wales (UNSW) and CSIRO looked at seasonal changes in pH and the concentration of an important chemical compound, carbonate, in the Southern Ocean.
The results, published in today’s Proceedings of the National Academy of Science, show that these seasonal changes will actually amplify the effects of human carbon dioxide emissions on ocean acidity, speeding up the process of ocean acidification by 30 years.
…
Once the acidity of the Southern Ocean reaches a certain level, the shells of these and other calcareous marine creatures will start to dissolve.
“That’s a really bad point to get to,” says McNeil. “After that point, we can’t go back unless we suck the CO2 out of the atmosphere.”
This so-called ‘tipping point’ of acidification had been predicted to occur when atmospheric CO2 levels hit 550 parts per million, around the year 2060.
However, the new research shows levels of the carbonate that these creatures need to build and maintain their shells drops naturally in winter, due to natural variations in factors such as ocean temperature, currents and mixing, and pH.
This means the tipping point is likely to be reached at far lower atmospheric CO2 levels – around 450 ppm, says McNeil, which also happens to be the target set by the IPCC for stabilisation of CO2 emissions.
Translation: Even if we’re “lucky” and the magic 350 number is too low, we could still wind up dealing a devastating blow to the oceanic food chain.
(The paper mentioned above doesn’t seem to be online yet.)
The Southwest in the Anthropocene:
Until recently, natural landscapes varied as droughts came and went, warm years were followed by cold years and so on. Now, though, the actions of people have widened the parameters of this natural change, with potentially troubling results in places like the Southwest.
That’s what William deBuys, an author and conservationist who has spent decades working in and writing about the region, says in the current issue of Rangelands, a publication of the Society for Range Management. (You can download a pdf of his essay here.)
In particular he is talking about the mountains and rangelands of New Mexico. Always shaped by fire, lately they have been shaped by fire suppression. Always modified by grazing elk and other animals, now they are threatened by overgrazing of livestock. Always vulnerable to drought, now they are stricken by drought and heat together. And the heat is not the heat of a normal warm year, it is the heat of human-induced climate change, he says.
Translation: When you jostle a complex system (like Earth’s biosphere), it can change its behavior drastically, often in extremely inconvenient ways.
Global Warming Predicted To Hasten Carbon Release From Peat Bogs:
Billions of tons of carbon sequestered in the world’s peat bogs could be released into the atmosphere in the coming decades as a result of global warming, according to a new analysis of the interplay between peat bogs, water tables, and climate change.
Such an atmospheric release of even a small percentage of the carbon locked away in the world’s peat bogs would dwarf emissions of manmade carbon, scientists at Harvard University, Worcester State College, and the Japan Agency for Marine-Earth Science and Technology write in the current issue of the journal Nature Geoscience.
“Our modeling suggests that higher temperatures could cause water tables to drop substantially, causing more peat to dry and decompose,” says Paul R. Moorcroft, professor of organismic and evolutionary biology in Harvard’s Faculty of Arts and Sciences. “Over several centuries, some 40 percent of carbon could be lost from shallow peat bogs, while the losses could total as much as 86 percent in deep bogs.”
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Each square meter of a peat bog contains anywhere from a few to many hundreds of kilograms of undecomposed organic matter, for a total of 200 to 450 billion metric tons of carbon sequestered in peat bogs worldwide. This figure is equivalent to up to 65 years’ worth of the world’s current carbon emissions from fossil fuel burning.
“Peat bogs contain vast stores of carbon,” Moorcroft says. “They will likely respond to the expected warming in this century by losing large amounts of carbon during dry periods.”
Translation: Have we pushed the boulder far enough down the hill that gravity will pull it away from us at an ever faster pace, no matter what we do now? No one knows yet with any degree of certainty.
So, what’s the point of this global warming mashup? Is this just another angst-fest, in which we all huddle around our monitors and rock gently, trying to wish all the Bad Things into the corn field? Is it yet another plaintive call to action, which far too few of us will answer?
Honestly, it’s up to you, because, as the saying goes: It is what it is. Scientists continue to peel back the layers of uncertainty around some of the most interesting questions in climate science, and the revelations they’re making are anything but cheering. As I’ve pointed out many times on this site, we’re going through a period when nearly all of the surprises related to global warming are very bad news, and these articles quoted above continue that unnerving trend. More CO2 in the atmosphere means more warming and polar melting, more changes to weather patterns (droughts in some places, floods in others), more threats to the oceans, and creeping ever closer to the ultimate climate tipping point where we’re carried away by unstoppable, self-reinforcing change.
If we choose to remain in denial and continue pouring immense amounts of CO2 into the atmosphere, then the biosphere will continue to respond in a way that’s ultimately disastrous for much of life on Earth. The only unknown is how quickly those changes will happen and the exact form they’ll take. As the old saying goes, reality is that which, even when you refuse to believe it, continues to exist. And that may be the least convenient truth of all.
