I discovered this unpublished post today, originally written in the Spring: A while ago I wrote a wikipedia article on extinction debt.  Frankly, researching this topic scared the hell out of me. Extinction debt began as a fairly obscure theoretical concept that emerged out of mathematical modeling exercises in ecology that showed that it could take tens or even hundreds of years for species to go extinct (Timan et al. 1994).

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Pollen Data for Williams (2010)

 

• List of sources of data, but not data, is in a table in the supplementary material
• Most records are from North American Pollen Database (NAPD)

• Just browsing through the datasets from this, it looks like a challenge may be that there isn't much data preceding most of the abrupt shifts - there may not be anything resembling a baseline.

   

Met with Stephen Pacala last week, who suggested we look into records of pollen sediments in lakes (varves) as potential data sources for early warning signals. Some potential sources: A paper reviewing regime shifts in the pollen records: Drying period in N. American midwest look promising Williams, J. W., J. L. Blois, and B. N. Shuman. 2011. Extrinsic and intrinsic forcing of abrupt ecological change: case studies from the late Quaternary.

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This week in Science, Shahid Naeem reviews two books (paywall) about modern, "novel" ecosystems, which humans have created by mixing together species that never evolved together.  He wonders, are such systems Frankensteins? Modern ecosystems that are haphazardly assembled from the remains of human development are unpredictable and fragile. With one billion people hungry, two billion poor and three billion in desperate need of water, the hopes of humanity rest on conserving, restoring and sustainably managing the services that nature provides.

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WRI continues the march of environmentally-driven credit analyses with a new report on the chemical sector and how climate regulation could effect industry's ability to borrow.  WRI looks at both congressionally- and EPA-driven scenarios for greenhouse gas regulation and maps how different chemical sub-sectors will be affected in each. Differences between cap-and-trade legislation and EPA-implemented regulation are interesting and not entirely intuitive.  For instance, based on previous attempts at cap-and-trade, legislation will probably provide free emissions permits to emissions-intense sectors for the first decade or so, leaving medium emitters the most exposed.

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