Diary of a Tree Stump
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Winds of Change
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Afterword to the softbound edition.
The Octopus and the Orangutan
The Future In Plain Sight
The Parrot's Lament
Affluence and Discontent
The Alms Race
Apes, Men, & Language
Forget SARS. What About the Weather?
Global climate change could have a far greater impact than worries about terrorism or disease
Friday, May. 02, 2003
When it comes to evaluating risks, both ordinary people and policymakers tend to be wildly inefficient. Remember that in the 1970s, intelligence officials, preoccupied with communism, discounted the threat posed by Islamic fundamentalism. The lesson: Ignored threats often pose more serious threats to global stability than the fears du jour. So with SARS and terrorism now dominating headlines and our worry space, it's worth pondering what threats have been squeezed out. The recent bad winter suggests one strong candidate for consideration: the threat of rapid climate change.
An important consideration in evaluating a threat is whether it is more likely to do its damage through uncertainty or by bringing about instability. Uncertainty is bad for an economy, but instability is a killer. In uncertain times people worry about whether to postpone a vacation, while businesses put off hiring decisions and reduce spending. In unstable times, people stockpile food or hit the road as refugees, while businesses shutter. Uncertainty focuses on worries about what the future might bring, while instability has to do with upheavals in the here and now.
Fears of terrorism and disease have already pummeled world economies, but, at least for the moment, the damage wrought by these threats comes more from their attendant uncertainties than their direct affects. So what might bring about actual instability? The endless winter in the northeast, for instance, may be a signal that an abrupt change in climate lies right around the corner. If so, large parts of the world might face ice age ? that's right, ice age ? conditions with virtually incalculable consequences for agriculture and travel, much less ordinary commerce.
The key to this threat is a recently discovered vulnerability of the Gulf Stream. The current, dubbed the Blue God by author William MacLeisch, warms much of Europe and eastern North America by bringing enormous amounts of tropical water northward as part of the "great ocean conveyor" that distributes heat around the world. As this warm water moves north, evaporation makes it saltier and heavier. By the time the stream has reached the far northern waters between Norway and Greenland it has given up most of its heat, and this salty, heavy water plunges into the abyss, pulling more water behind it.
This is where our warming globe can screw things up, according to scientists such as Robert Gagosian, president and director of the Woods Hole Oceanographic Institution in Massachusetts. The melting of glaciers and increased precipitation in the north has poured fresh water into the Atlantic, in some places leaving a ten foot thick layer on the ocean surface, according to Terence Joyce, also of Woods Hole. As the lighter fresh water slows the sinking of the Gulf Stream as it hits these northern latitudes it reduces the pull that brings warm water northward. Scientists estimate that the speed of the conveyor in the far north has diminished by 20% since the 1970s. Coincidence? Perhaps, but the synchronous freshening of the North Atlantic, a less vigorous Gulf Stream, and a cold snowy Northeast when the rest of the world is baking (last year was the second warmest year on record), may be conveying an urgent message. Something like this happened 12,700 years ago when a post-ice age warming suddenly reversed and in just a few years plunged much of the North Atlantic region into a 1,300 year deep freeze.
If this signals the beginning of an abrupt change in climate, instabilities that dwarf the threat of terrorism lie in our future. If these great ocean currents are interrupted, temperatures in the Northeast might drop 10 degrees F (this winter represented a drop of about 2.5 degrees F) in less than a decade. Naturally, one winter does not an ice age make, and maybe our cold winter represents nothing more than a byproduct of regularly recurring cycles such as the North Atlantic Oscillation and El Nino. At the moment we don't know.
But maybe we should try to find out. As recently as the 1980s, a cold winter was a curiosity, an outbreak of a new disease, a problem for the third world, and, while the Soviets had many nuclear weapons, they knew better than to use them. Today's tightly connected globe means that uncertain times create a petri dish in which destabilizing fears multiply. Worse, if climate change does come about and those fears become real, the damage will be far greater if we're not prepared.
Such uncertainties will be with us for the foreseeable future, dampening spending and investment, and leaving regions prone to sporadic panics. The last thing the public needs right now is another threat on people's minds, but a little more attention to rapid climate change is in order. In an uncertain world, the first order of business is to know what to worry about.
An oped involves extreme compression, and so I thought I’d expand on why I think the initial IPCC reports so underestimated the threat. Make no mistake, the consensus in the summaries for policy makers in the first two assessments did underestimate the threat. The consensus was that permafrost would be stable for the next 100 years and also that the ice sheets would remain stable (there was even a strong sentiment at that time that the East Antarctic sheet would gain mass). Moreover, in 1990, the concept of rapid climate change was at the periphery of mainstream scientific opinion. All these things turned out to be wrong
Of course, there were scientists at that time who raised alarms about the possibility of rapid climate change, collapse of the ice sheets, and nightmare scenarios of melting permafrost, but, fairly or not, the IPCC summary for policy makers was and is taken to represent the consensus of scientific thinking.
In my opinion such documents will always take a more conservative (less dramatic) position than what scientists feel is justified. For one thing the IPCC included policy makers, most of whom were more incentivized to downplay the threats. For another, many of the national governments that were the customers for these assessments barely tolerated the exercise and gave strong signals that they didn’t want to see anything that called for dramatic action, and this being the UN, there was a strong push to present a document that as many governments as possible would accept.
And then there is the nature of science and the state of climate science at that point. There is an inherent structural lag built in to the nature of science. For instance, the 1980’s were marked by the rapid development of proxies to see past climate changes with ever more precision. By the mid-late 80’s the proxies and siting had been refined sufficiently that the GISP and GRIP projects could confidently get ice cores from Greenland that they felt represented a true climate record and by then they also had the proxies with the resolution to see the rapid changes that had taken place in the past. Given the nature of data collection, interpretation, peer-review and publishing, it wasn’t until 1993 that these results were published.
It took nearly another decade for this new, alarming, paradigm about how rapidly global climate can change to percolate through the scientific community, and, even today, much of the public is unaware that climate can change on a dime.
As for the ice sheets, when I was on the West Antarctic Ice Sheet in 1996, there was talk about the acceleratio of ice streams feeding the Thwaites and Pine Island glaciers, but the notion that there might be a significant increase in runoff from the ice sheet over the next hundred years was still very much a fringe idea.
With permafrost, the problem was a sparsity of data in the 80s and early 90s and it is understandable that scientists didn’t want to venture beyond the data.
The problem for society as a whole was that the muted consensus on the scale of the threat diminished any sense of urgency about dealing with the problem. Perhaps the best example of this was the early work of William Nordhaus. Working from the IPCC best estimates in the early 1990s Nordhaus published one paper in which he predicted the hit to the US GDP from climate change in 2100 would be about ½ of 1%. Nobody is going to jump out of their chair and demand action if the hit to the economy was going to be 0.5% of GPD a hundred years laterLibertarians such as William Niskanen seized on this and testified before Congress that there was plenty of time to deal with global warming if it was a threat at all.
And then there was the disinformation campaign of industry, particularly fossil fuel lobbyists, as well as pressure from unions (the UAW in particular) and the financial community. These highly motivated, deep-pocketed interests seized on scientific caution to suggest deep divisions among scientists and that the threat was overplayed. Little wonder then that the public failed to appreciate that this was a looming crisis that demanded immediate, concerted action.