It’s not surprising that one of the tweets floating around after this came out was that the WSJ had been bought by the Onion.
Climate deniers Will Happer and Harrison Schmitt embarrassed themselves with a most peculiar piece in the Wall Street Journal the other day extolling the benefits of CO2 for plants. Why they chose to flog this particular dead horse, not sure. I’ve debunked that myth numerous times, and could have saved them, and the WSJ, some embarrassment.
Seriously – I’m here to help, folks.
For the record, Happer is a physicist, Schmitt a Geologist who went to the moon, and clearly have learned their ag science from climate denial web sites. I’m old fashioned enough to ask someone who actually has spent a lifetime working with plants and crops at a leading Ag institution about the mainstream view of this matter – I met and interviewed Phil Robertson of Michigan State University last summer, (see relevant clip above) and he recently emailed a pithy synopsis of the CO2-plant issue:
CO2 enrichment experiments in natural vegetation including forests and rangelands (both of which are agricultural as defined by USDA) usually show an initial increase in productivity that quickly comes to a hard stop as nitrogen limitation is expressed, usually within a few years. Same is true for unmanaged ecosystems.
Dr Schmitt has shown himself to be truth-challenged in his previous statements on climate issues, and prone to making allegations that those of us concerned about environment and our children’s future are, well, commies. The spotlight that this blog and others shone on that kind of crazy cost him a high level job in Arizona State government a couple years ago.
See below for a quick recap of his climate cherry picking.
And finally, here’s the ClimateCrocks take from a couple years back on the whole CO2/Plant canard.
Happer is not just a Princeton professor of atomic physics, and not just a director of the George Marshall Institute, with Fred Singer the primary focus of OReskes&COnway, Merchants of Doubt.
From 2006-onward, he’s been the Chairman of the Board.
Its CEO is William O’Keefe, a 25-year veteran exec at the American Petroleum Institute.
I am a graduate of the University of Agricultural (finished it with distinction – prizes). I am currently working in the field of Agrometeorology and Agroclimatology.
I have taught students of CO2 fertilization in greenhouse production. The tomato crop even concentration 1200 – 1500 ppmv of CO2 are effective – at the long times. In plant nursery (including in vitro) these concentrations also cause such faster and more abundant production of roots and cicatrize of wounds, more profuse …
Cherry picking …
Both the supporters and opponents of the theory of AGW use cherry picking in this matter – it’s true.
Here is an example of using cherry picking by the supporters of AGW:
Drought-Induced Reduction in Global Terrestrial Net Primary Production from 2000 Through 2009 – Zhao & Running (2010, -http://www.sciencemag.org/cgi/content/abstract/329/5994/940): “The past decade (2000 to 2009) has been the warmest since instrumental measurements began, which could imply continued increases in NPP; however, our estimates suggest a reduction in the global NPP of 0.55 petagrams of carbon. Large-scale droughts have reduced regional NPP …”
“A continued decline in NPP would not only weaken the terrestrial carbon sink, but it would also intensify future competition between food demand and proposed biofuel production.”
Comment on “Drought-Induced Reduction in Global Terrestrial Net Primary Production from 2000 Through 2009” – Medlyn (2011 – http://cliveg.bu.edu/research/science-tc-2011/medlyn.pdf):
“The reported reduction in NPP is clearly a consequence of the chosen assumptions.”
“However, it is important to clearly present the assumptions underlying a modeling study, and correctly describe the conclusions. ZR10 have not shown, as claimed, that terrestrial NPP has decreased over the last decade. Rather, they have shown that if NPP is assumed to be affected by climate as specified in their model, then NPP would have declined over the past decade. It is important to make this distinction, because otherwise we run the risk of mistaking model outcomes for reality.”
Comment on “Drought-induced reduction in global terrestrial net primary production from 2000 through 2009”, Samanta (2011. – http://www.ncbi.nlm.nih.gov/pubmed/21868655S cience):
“Zhao and Running (Reports, 20 August 2010, p. 940) reported a reduction in global terrestrial net primary production (NPP) from 2000 through 2009. We argue that the small trends, regional patterns, and interannual variations that they describe are artifacts of their NPP model. Satellite observations of vegetation activity show no statistically significant changes in more than 85% of the vegetated lands south of 70°N during the same 2000 to 2009 period [… ??? !!!].”
Full analysis (and critique) is here: Net primary production of terrestrial ecosystems from 2000 to 2009, Potter (2012 – http://geo.arc.nasa.gov/sge/casa/Potter_2012_ClimCh.pdf )
Scientists (experts in the field of knowledge) write about the relationship between NPP – pCO2, thus:
Effect of soil moisture and CO2 feedbacks on terrestrial NPP estimates, Dev Niyogi, Yongkang Xue, Sethu Raman, North Carolina State University, University of California at Los Angeles (http://ams.confex.com/ams/pdfpapers/38448.pdf):
“Often, despite dramatic leaf level impacts due to climate changes, the natural ecosystem tends to buffer and does not show a dramatic response. Our analysis suggests that the interactions between the biotic and abiotic changes tend to have a compensatory /antagonistic response. This reduces the effect of the variable change on the overall system response.”
Similar conclusions are here:
‘Greener’ Climate Prediction Shows Plants Slow Warming, Lynch comment – NASA, (2010, -http://www.nasa.gov/topics/earth/features/cooling-plant-growth.html): “Of those that have attempted to model this feedback, this new effort differs in that it incorporates a specific response in plants to higher atmospheric carbon dioxide levels. When there is more carbon dioxide available, plants are able to use less water yet maintain previous levels of photosynthesis. The process is called “down-regulation.” This more efficient use of water and nutrients has been observed in experimental studies and can ultimately lead to increased leaf growth. The ability to increase leaf growth due to changes in photosynthetic activity was also included in the model.”
… and here:
Interannual variability and climate sensitivity of Net Primary Productivity: a process-based multilayer-canopy vegetation model compared against observed tree-ring width, Bodin, Alton, and Krakauer, (2010 – http://www-ce.ccny.cuny.edu/nir/papers/Bodin_submitted_2010.pdf):
“We estimate a global increase in NPP of 0.32% yr – 1 over the period 1951-2000. This is in
approximate agreement with previous studies. Most of this increase can be attributed to CO2 fertilization rather than climate change.”
RUBISCO …
The relatively recent past (geologically – above. 3 million years) it (RUBISCO) “lived” in a concentration two times higher than the current (http://www.ldeo.columbia.edu/~polissar/teaching/F2012_G9600_Climate_Puzzles_of_the_Neogene/LaRiviere_etal_2012_Suppl.pdf – Fig 1., according to some data it’s could even have been more than 500 ppm CO2).
The global weight of biomass was often in the past, many times higher than today. This proves that both N and P, or Fe does not limit the GPP (regional only).
The NPP of the ocean yet we know very little – we have problems with the measurements (Pratt, 2010.http://ams.confex.com/ams/90annual/techprogram/paper_166349.htm).
Whether photosynthesis will always be “falling behind” with the increase of CO2?
At the moment we are in the phase of linear growth (in the long-term trend): both pCO2 and NPP are growing just as fast (Knor, 2009 – http://www.agu.org/journals/ABS/2009/2009GL040613.shtml)
It is compatible with a model L-V (http://upload.wikimedia.org/wikipedia/commons/a/aa/Volterra_lotka_dynamics.PNG). Here you can see, however, that after a linear growth phase of “predators” and food, the predator gets “the edge”. As a result of this phenomenon, we have two divergent – at a time – bell-shaped curves.
It has always been in the future: NPP “catching up” and “was ahead of” p.CO2 -Yu (2010 – http://lwf.ncdc.noaa.gov/paleo/pubs/yu2010/yu2010.html): “Combined benthic δ13C and [CO3 2-] results indicate that deep-sea-released CO2 during the early deglacial period (17.5 to 14.5 thousand years ago) was preferentially stored in the atmosphere, whereas during the late deglacial period (14 to 10 thousand years ago), besides contributing to the contemporary atmospheric CO2 rise, a substantial portion of CO2 released from oceans was absorbed by the terrestrial biosphere.”.
Why have be so now?
Optimum p.CO2 for most of C3 plants (plants with C3 photosynthesis react quickly to increase p.CO2) is 500-600 ppm (although some C3 plants have optimum even higher – up to double).
Always (for C3) is at least 20% more than the current CO2 concentration. Up to 600 ppmv CO2 NPP C3 grows rapidly (http://buythetruth.files.wordpress.com/2009/06/photosyntheticrates.jpg?w=372&h=352).
How quickly NPP (logarithmic) gain an advantage over CO2 emissions?
We do not know.
Ice cores have very low resolution – at a time, but fossil stomata show that they are a maximum hundreds not thousands of years.