With a new president and Congress, the climate change story increasingly will be about policy and politics. Is cap and trade the best way to go? Would a carbon tax be better? What other options should be considered, and what are the costs and benefits?
The fiery debates over these questions that may begin in just weeks will be driven by an objective first spelled out in the United Nations Framework on Climate Change: preventing “dangerous interference” with the climate system. But as Stanford climate scientist Stephen Schneider points out, it’s difficult to say for sure where the thresholds of danger lie. And what’s dangerous to some may be entirely benign to others.
So rather than seek absolute answers to questions that often will have no such answers, journalists covering climate change should seek scientific assessments of the risks associated with various options (such as allowing concentrations of greenhouse gases to accumulate in the atmosphere to greater or lesser degrees). Moreover, the coming battles that will be waged over scientific assessments of those risks will be informed just as much by values as by scientific data. Some participants in the policy debate will value short-term economic growth and profits very highly and may therefore perceive the risks of climate change far differently than those who place greater value on what they see as long-term sustainability of the economy.
And here’s my own editorial comment: Sorting all of this out as a journalist could prove to be much more difficult that covering the technical details of the science.
These were among the issues I discussed with Schneider in a recent interview for an article on climate change I am working on. Schneider holds several positions at Stanford, including the title of Melvin and Joan Lane Professor for Interdisciplinary Environmental Studies. The interdisciplinary part of that title is appropriate, because he is just as comfortable talking about policy as climate science. And the approach he urges them to take in grappling with climate change is risk management.
The risk to be avoided — dangerous interference with the climate, — was spelled out in the framework convention, which was ratified by the U.S. Senate on October 7, 1992, and by 192 countries overall:. . . stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.
But what constitutes “dangerous” interference? The convention didn’t specify. So that question went to the Intergovernmental Panel on Climate Change. Schneider was a co-lead-author on the chapter in the most recent IPCC assessment devoted to addressing that question. “Right off the bat we had to distinguish between risks, which involves scientific judgment, and how to manage those risks, which involves values,” Schneider said.
Here’s another way to think about this: “Given the risks we’ve identified, how many chances do you want to take with planetary life support systems, versus how many chances do you want to take with the economy?” Science informs that decision, but how the answer comes out depends on our values.
“What to do about the risks?,” Schneider asks. “That’s a value judgment, and that’s the government’s job, the corporations job, an individual’s job.”
A coal company will bring different values to answering how many chances we should take with our life support systems versus the economy. “But if you’re an Inuit, you’ve already crossed the threshold of dangerous change because your hunting culture is going extinct.” Other people have already crossed the threshold as well, he said — including Californians, who have been experiencing a significant increase in the frequency of wildfires, which bring myriad serious impacts, not the least of which are impacts to health.
“So you could argue that we’re already approaching the threshold of dangerous climate change,” Scheider said. “But only for certain groups. When do you harm enough people to justify spending trillions of dollars on fixing the problem?”
Schneider and his colleagues tackled the issue of risk management in their chapter in the IPCC report. Among its conclusions were that a temperature rise above 2 degrees C over 1990-2000 levels (we’re currently at 0.74 degrees C), “would exacerbate current key impacts,” such as more human deaths, melting of glaciers, and increases in the frequency or intensity of extreme events. A high confidence level was assigned to these predictions.
If temperatures rise to between 2 and 4 degrees C, the result would be “an increasing number of key impacts at all scales (high confidence), such as widespread loss of biodiversity, decreasing global agricultural productivity and commitment to widespread deglaciation of Greenland (high confidence) and West Antarctic (medium confidence) ice sheets.
If global mean temperature should rise more than 4 degrees C, major changes would happen in areas of key vulnerability — changes that would, in fact, “exceed the adaptive capacity of many systems (very high confidence).” In other words, we’d really be in trouble. But again, which of these degrees of interference would qualify as “dangerous”?
Answering that question will not be easy, because different people will have very different answers. “Now we’re entering into the political wars,” Schneider noted.
The European Union has concluded that a rise of 2 degrees C is dangerous. “We’re already at an increase of .75 degrees C, so we have only 1.25 to go,” Schneider said. “And it’s very likely that we will exceed what EU is calling dangerous.”
In fact, it is possible that we are already committed irreversibly to significant sea level rise. “But maybe not.” The uncertainties in the science are large. “We know that thresholds like this exist, but we don’t know exactly know where they are,” Schneider said. That is a major focus of ongoing scientific work.
“So we got a real conundrum here.” The countries that have so far been responsible for most of the increased concentrations of greenhouse gases in the atmosphere are colder and richer and have substantial abilities to cope with climate change. Meanwhile, the countries that have been least responsible, at least so far, are generally warmer and poorer and “actually have the most to lose,” Schneider said. This has been a major sticking point in climate change negotiations, of course, with countries like China and India saying they should be allowed to develop unfettered while the developed world does most of the heavy lifting. But China has passed the United States as the biggest greenhouse gas emitter. Without any curbs on emissions from these rapidly developing nations, we could be in for some very serious trouble.
“We’ve gotta have a compromise here,” Schneider said. “That’s what is going to play out in Copenhagen,” where the next major international climate change conference — the Conference of the Parties — will take place next fall.
For scientists, the focus in coming years will be on identifying the thresholds of danger as quickly as possible, so politicians can decide what risks are acceptable. Schneider said that won’t be solved any time soon, “but we will be working our butts off on it.”