Steve Pacala - Storer lecture

Excellent visit from a former advisor, Steve Pacala, at Davis for a Storer lecture.

 Seminar

  • atmospheric CO2 is roughly half CO2 production, rest is being mitigated by the natural carbon sink

  • Carbon sink is half ocean, half terrestrial

A grim future:

  • 450ppm not feasible

  • 500ppm best case

  • 550ppm is likely even if we are largely successful

Even worse if the terrestrial sink collapses.  Will it?  Discussion of GCM models.

There’s no reason to trust these models - and I make them. - 100’s of free parameters. This is the nature of an ecological crisis. the policy world needs an answer. the science isn’t ready, and that’s just tough.

Current climate models predict collapse of sink due to carbon enrichment going mostly into fine roots, rather than more lasting trunks.  These disagree with the FACE experiments at Duke manipulating the carbon enrichment of trees empirically.  Current carbon methods scale the leaf to the globe, and have forgotten the lesson of Gersani’s soybeans (Gersani et. al. 2001). Steve elegantly summarized:

Nature isn’t a meritocracy. it’s more like an sat test where you can also kick people in the face.

Next is a beautiful recap of approximating the individual-based simulation forest SORTIE models into the analytically tractable PPA model with hopes that this can scale to the global scale, wonderfully described in Purves et al (Purves et. al. 2008), which I cut my teeth on as an undergraduate.

What follows next is upcoming insights from his grad student Caroline Farrior and others on root-shoot competition that may resolve the FACE/GCM paradox. (unpublished, no notes here yet).

Speaker dinner

Perhaps the best part of the Storer lectures is the session after dinner where the guest is invited to expound upon any topic of interest and controversy. Sometimes this feels like roasting the guest, but tonight it was more the other way around.  Steve reminded us of the poor state of science recognition in the country (most Americans cannot name a single scientific agency they trust – a few come up with NASA, and a few with CDC, and no one has heard of the National Academy).  He then challenged us to answer what we were doing about it, and shared some insights from their work at Climate Central.

After much study, their team has decided that Americans trust local weather media anchor the most of almost any authority, and tend to turn to this source particularly during extreme weather events.  These anchors are well rewarded for this trust as some of the best paid media positions, making some $2e6 a year.  Couple this with two other key observations: (1) during a weather crisis, people are most receptive to ideas about climate change (Hurricane Katrina is perhaps the best example); and (2) these anchors love discussing data on climate change during these events.

The latter surprised me – anyone else trying to get trust of the public avoids controversial topics.  But for the local weather anchor, this lets them say things like “the heat waves this summer are twice as frequent as the heat waves our grandfathers in this town experienced.”  It gives them something to talk about, and it gives their viewers something to talk about, call in, and post on their blogs, driving up their ratings.

The facts are there. (Pacala even observed that the US military uses a moving-average weather model to get accurate forecasts because they just couldn’t get accurate predictions in combat areas without building climate change into their models). To sway the American public, we just need to get the current conditions compared to historical conditions, wait for the next extreme weather, and demonstrate it’s a statistical outlier, and get the data into the hands of the local weather news anchors.  Everywhere in the US.

Pacala didn’t get much push back on this, though the connection of extreme weather and climate is of course not the favorite tack of scientific community.  It was onlythis Septemberthat Nature ran a series of pieces putting this forward seriously(Schiermeier, 2011) - the articles and comments make great reading.

Meeting

Discussion of warning signals and potential data sets, particularly for spatial systems.

  • Black hawk island - spatial waves in tree dynamics between maples (improve soil strategy) and spruce (degrade soil strategy).

  • Varve lake pollen deposits – very rich history.  Suggested a European database and US database, still trying to track these down. The European one?

References