Monday, September 26, 2011

The folly of broad statements about adapting to climate change

In my climate change course, we devote a week to discussing climate and past civilizations. Among the goals of that week is to erase the notion that climate change is inherently "bad", or inherently "good", from the student's minds. The effects of climate change on any system, whether a society or an ecosystem, depends on the adaptive capacity and the rate of the climate change. The same climate change that spelled the end of the Norse settlements in Greenland did not affect (ed. crowd-sourced copy editing) the well-adapted Inuit of the region.

A recent, and controversial, book hypothesizing that the Easter Islanders were not done in by "ecocide", as argued by Jared Diamond and most archaeological evidence suggests, led to some discussion about the societal resilience to climate change. All roads lead to climate these days, I guess.

Judith Curry concludes a post on the subject with this statement, which supports a dangerously simple view of adaptation to climate change:

Occam’s razor suggests that we should tend towards simplest theories.  However, in complex coupled social-ecological-environmental systems, simple theories are almost certain to be too simple.  The complexity of such coupled systems precludes simple cause-effect analyses.   If we are arguing about such a system on the scale of Easter Island, what hope do we have of understanding and managing such interactions on  continental or even global scales? Ecosystems eventually adapt to climate change and insults from humans.

The comments about Easter Island notwithstanding - we argue about places like Easter Island because it all happened in the past and thus evidence is disputable, not because we can't understand complex systems - this statement concludes with exactly the type of simple, blanket view of complex problems that we should be teaching students to avoid. Theories like "Ecosystems eventually adapt to climate change and insults from humans" are indeed too simple!

Ecosystems do adapt. In a broad sense. But the question is not if they can eventually adapt, because we don't live in eventually. And, regardless of the time frame, we must remember that adapt itself is a vague term. To estimate the impacts of climate change, or other human insults, in the real world, we need to delve deeper and dispense with the vague generalities:

1. Define eventually: At what rate can the system adapt? Is the change happening faster than ecosystems, or people, can adapt such that they stay in the present state?
2. Define adapt: What exactly does adaptation look like? Say, coral reefs can "adapt" (in a collective, rather than an individual biological sense) to climate change by killing off the less resilient species and growth forms. That, for example, may be what is happening in South Tarawa where I do field work. You've got reefs dominated by a single, weedy species, and little habitat diversity. This new adaptation may not be desirable for those who depend on the ecosystem.

That's science. You don't just assume away an answer ("oh, we'll be just fine") based on a pre-conceived notions of what's "good" or "bad". You gotta analyse the data, do the math, unpack how the system works.


Thursday, September 22, 2011

Climate change: An accounting problem

The latest RealClimate post, which describes the latest ice melt data from Greenland, features this really important figure. It illustrates an issue that arises every semester in my climate change course, and is, in a sense, fundamental to understanding to biogeochemical cycles and issues like why carbon is accumulated in the atmosphere.

The figure shows model-based annual anomalies (thanks ED) of snowfall (reddish-orange), water loss through surface melt and runoff (yellow) and net accumulation of mass (blue), all in Gt/yr. The key point is that an ice sheet shrinks not simply because it is melting (yellow), but because the loss of water through melt (yellow) is greater than the gain through snowfall (red). The difference is the change in mass (blue). It is an accounting problem; like your bank account, you need to look at the debits and the credits to know whether the balance is changing.

This is the same fundamental concept that  underlies carbon dioxide accumulation in the atmosphere, and as MIT management expert John Sterman has shown, befuddles most people. Carbon dioxide is accumulating in the atmosphere not simply because we are burning fossil fuels and clearing land, but because the flux in to the atmosphere from those sources is greater than the flux out (to land, and the oceans).

As an aside, in my climate change course, one of the many ways we discuss these points is by watching the infamous "CO2 is life" advertisements created a few years back by the Competitive Enterprise Institute. The "Glaciers" video cites scientific evidence for snowfall-driven growth of ice sheets in the interior of Antarctica to suggest that ice sheets around the planet are not shrinking. The mistake in the ad is that in order calculating whether an ice sheet is shrinking, on net, you need to do the full accounting of all inputs (from snow) and all the outputs (from melt), not just cherry pick one part of the ice sheet, or one flux in or out.

The CEI ads, by the way, are hilarious. If you've not seen them, you really must. They are well worth two minutes out of your day; the Onion News Network couldn't have come up with fake ads that funny.


Tuesday, September 20, 2011

24 Hours of Reality, 365 days a year

If you missed it live, all of the videos from the 24 Hours of Reality are available online. Pick a region of interest and watch the video. Each hour is comprised of a short introductory video, a local speaker delivering a variation of Al Gore's presentation about climate change, followed by a panel of experts back at the studio talking about the science and the issues.

The panel members rotated throughout the 24 hours based on expertise, and who could stay awake. Kudos to Paul Higgins from AMS for doing the overnight shift as well as some of the daytime panels. It's worth watching the highlights from multiple hours and/or watching multiple panel discussions, as the rotating cast made for some fascinating and interesting conversations. I was a part of panels that included Al Gore and four scientists (Kotzebue, Alaska, Hour 4) as well as mix from academia, broadcasting the UN, Hollywood and NGOs (French Polynesia, Hour 5; Dubai, Hour 16).


Monday, September 12, 2011

Climate reality... What a concept.

Starting a 8pm EST on Wednesday night, the Al Gore's Climate Reality Project will be doing a 24 hour live broadcast of people around the world talking about climate change. Here's their pitch:

24 Presenters. 24 Time Zones. 13 Languages. 1 Message. 24 Hours of Reality is a worldwide event to broadcast the reality of the climate crisis. It will consist of a new multimedia presentation created by Al Gore and delivered once per hour for 24 hours, representing every time zone around the globe. Each hour people living with the reality of climate change will connect the dots between recent extreme weather events — including floods, droughts and storms — and the manmade pollution that is changing our climate. We will offer a round-the-clock, round-the-globe snapshot of the climate crisis in real time. The deniers may have millions of dollars to spend, but we have a powerful advantage. We have reality.

I'll be taking part in some of the expert panels back in the studio, discussing some of the science and some of the issues after the on-site presenters are finished (for updates on times, follow me on Twitter: @simondonner).

As regular readers of Maribo, or people who heard my talk at AMS this spring know, I've been an advocate of what one might call a "humbler" approach to outreach about climate change. That approach is informed by my field research in the Pacific Islands, some related historical research over the past five years, and my outreach experience; the argument for it is described in a paper currently in press with the Bulletin of the American Meteorological Society (more on that later). I'll be bringing some of that thinking to portions of the broadcast.

In case you are not a child of the 80s... the title of this post is a play on a Robin Williams comedy album from the Mork and Mindy days.


Wednesday, September 07, 2011

Joining the twitter-verse

Following up on a promise made earlier this summer to expand to other online "media", I've joined Twitter (@simondonner).

I was initially quite skeptical of Twitter. That should come as no surprise; I am a scientist, an academic one at that, and skepticism is what we do. But the last thing the world needs is more academic curmudgeons.