Ozy(mandias)fest 2008: Political v. Climate Change

My read of these various threads comes down to two basic points: the framework we (generally) use when we discuss how to limit climate change for the future, and the sense of priority that the U.S. has about climate change issues.

Much of the serious climate mitigation discussion about limiting carbon emissions involves debate about two numbers. The first number is the atmospheric concentration of carbon dioxide where we (globally) should stabilize, expressed in parts per million (ppm). The current level is about 385 ppm or so, while the recent preindustrial concentation is generally cited at 280 ppm. The presumed “targets” for this century are usually 450, 550, or 650 ppm, depending on how dark and cynical the speaker is feeling. Most of the substance of the debate centers on how quickly we can reduce the rate of emissions to have a “soft landing” at a low ppm number.

The second number used in these discussions focuses on how much climate change we’re already “committed” to and cannot avoid. This number is supposed to reflect mean (average) global air temperature in degrees celsius and is almost always described as a series of increases relative to recent preindustrial temperatures: +2°, +4°, or +6°. This debate assumes that (a) we’ve already realized or achieved 1.8° C over preindustrial mean global air temperatures, and (b) increases larger than 2°C will be very difficult for people and non-human species to adapt to. Remember: air temperatures follow from carbon dioxide concentration, because extra carbon in the atmosphere absorbs more of the sun’s energy, which ultimately affects all parts of the climate. While global mean air temperatures sound relatively small (2°C is about 3.6°F), when we look at how temperatures show up on the ground, some places like the Arctic are seeing very high temperatures already at “only” global mean 1.8°C. An average is just an average. And a lot more than just air temperatures are shifting.

One unspoken area in most of these debates about where to stabilize is actually very scary. In the language of the IPCC, this area is referred to as “nonlinear” or “state-level” change. This vague term refers to the problem most of our climate modeling has with describing any kind of shift in climate that isn’t gradual and smooth. We have a very good idea from our past climate records that big changes are usually sudden and dramatic, more like going from climate state A to state B rather than proceeding 1, 2, 3, 4.... 10. In effect, nonlinear or state-level change is like turning on a light with a switch. What does nonlinear change look like? A series of small-seeming changes in weather patterns on the Pacific coast of North America have apparently created a new seasonal “dead zone” offshore that probably is now a regular feature of the regional climate. Now we see big marine species die-offs each year off the Oregon and Washington state coasts. That’s a small (in global terms) nonlinear state-level change. The presumption is that higher carbon concentrations and global mean air temperatures are more likely to result in more and bigger nonlinear changes. And that kind of change will be very, very difficult for people or species to adapt to because it is fast and dramatic. It will probably also be impossible to turn back even with a lower carbon ppm.

The other type of nonlinear change that scares people and that is also difficult to model is called a positive feedback loop. Here, the idea is that we pass some kind of threshold level of change or tipping point in the global climate system where natural ecosystems begin to pump out their own high levels of carbon dioxide or methane (a really bad form of atmospheric carbon). There’s a lot of methane on the ocean floor and in the permafrost in the high latitudes of Russian, Canada, Scandinavia and Finland, and Alaska. The melting of that permafrost is releasing a lot of carbon, which then enters the atmosphere and causes more warming. Higher air temperatures thus lead to .... even higher air temperatures. No one knows what concentration of carbon dioxide or mean global air temperature corresponds to irreversible positive feedbacks, which would mean that our climate mitigation efforts and negotiations are mostly for naught. A few credible scientists have suggested that we are on the edge of such change — either just in front of that edge or, terrifyingly, now teetering over. Perhaps it is best for our piece of mind that we won’t know where the edge for at least another decade.

That’s all very scary stuff. The recent scientific papers mentioned above, especially the editorial in PNAS by Schellnhuber, suggest that we’re going to stabilize at one of the higher concentrations and that we’re already committed to at least 2.4°C even if we effectively do everything right and we do it right now. He writes: “My conclusion is that we are still left with a fair chance to hold the 2°C line, yet the race between climate dynamics and climate policy will be a close one.” I thought: this is Ozyfest 2008.

Not Ozzie Osbourne, of course. I mean Ozymandias, a character created by Percy Bysshe Shelley. He enjoined an observer to look upon a barren wasteland that was once ole’ Ozy’s rich kingdom, now in ruins: “Look on my works, ye Mighty, and despair!”

The current financial crisis in the U.S. and globally is replete with despair, but it may be the wrong kind of despair. Policy change takes time to prepare and then a social commitment and money to enable shifts in our economy and behavior. The massive amounts of money required to “repair” the U.S. economy mean that we cannot put that money into many other worthy, even critical priorities, such as science funding, healthcare, and adapting infrastructure for climate change. In fact, climate change issues were essentially ignored by McCain and Obama in last night’s debate.

If there is good news, it is that climate mitigation is really very simple conceptually and is mostly about working through parochial objections about various lifestyle and industrial changes, as well as the relative contributions over time from the developed and developing worlds. Those are big issues, but they’re clear ones. The way forward is intellectually obvious. (The story about how we respond to and prepare for negative climate impacts — climate adaptation, my line of work — is far more local and intricate.)

But the bad news is that we’re not focusing on these issues during the U.S. election. The U.S. priority on climate change is low and declining. Our focus seems exclusively to be on acute issues. Though they are important concerns, the relative scale and scope of political issues needs to be kept in mind as well.

The Great Depression lasted about a decade. We’ll face strong impacts from anthropogenic climate change for centuries, even if major changes can be made and implemented quite soon. Our choice is really about how major those impacts will be, and if we cross over into Ozy’s wasteland. Ozy is pointing the way, hoping we can join him.

Tags: climate adaptation, climate mitigation, policy, news