Sunday, April 24, 2011

Remember the scary "single most-important finding in climate science last year": "a sharp decline" in phytoplankton? Never mind

The MSM was awash with alarmist reports last year that global warming had caused "a sharp drop" in ocean phytoplankton since the 1950's, with one newspaper stating "the single most-important finding in climate science last year was a 40 percent decline in the ocean's phytoplankton caused by global warming." A new paper published in Nature finds that multiple data sets instead show an increase in ocean phytoplankton over the past eight decades. Don't hold your breath for any retractions of the alarmist claims in the MSM, nor any stories reporting the good news.

Is there a decline in marine phytoplankton?

Nature  Volume: 472, Pages:  E6–E7  Date published: (14 April 2011)
Arising from D. G. Boyce, M. R. Lewis & B. Worm Nature 466, 591596 (2010); Boyce et al.
Phytoplankton account for approximately 50% of global primary production, form the trophic base of nearly all marine ecosystems, are fundamental in trophic energy transfer and have key roles in climate regulation, carbon sequestration and oxygen production. Boyce et al.1 compiled a chlorophyll index by combining in situ chlorophyll and Secchi disk depth measurements that spanned a more than 100-year time period and showed a decrease in marine phytoplankton biomass of approximately 1% of the global median per year over the past century. Eight decades of data on phytoplankton biomass collected in the North Atlantic by the Continuous Plankton Recorder (CPR) survey2, however, show an increase in an index of chlorophyll (Phytoplankton Colour Index) in both the Northeast and Northwest Atlantic basins3, 4, 5, 6, 7 (Fig. 1), and other long-term time series, including the Hawaii Ocean Time-series (HOT)8, the Bermuda Atlantic Time Series (BATS)8 and the California Cooperative Oceanic Fisheries Investigations (CalCOFI)9 also indicate increased phytoplankton biomass over the last 20–50 years. These findings, which were not discussed by Boyce et al.1, are not in accordance with their conclusions and illustrate the importance of using consistent observations when estimating long-term trends.


  1. Your link to the "new paper" is to Boyce et al (2010), which *does* show a ~1%/yr decline in phytoplankton. That's at odds with what you wrote in your post. And your "reply" link doesn't work. So what are you trying to say here?

  2. The Boyce 2010 article was the source of the hoopla last year. This new article refutes Boyce 2010. Thanks for pointing out the broken links which I have now fixed. The new article is here:

  3. Why didn't you include a link to the reply of Boyce et al to the Brief Communication of McQuatters-Gollop et al?


    see also