Millions of people are alive today because the net emissions of carbon dioxide have increased. These extra emissions have provided essential fertilization for crops around the world. Craig Idso has released a new report calculating that the extra value that the rise in CO2 has produced from 1961 – 2011 is equivalent to $3.5 trillion dollars cumulatively. Currently the extra CO2 is worth $160 billion dollars annually. Big-biccies. Projecting forwards, increasing CO2 levels could be worth an extra $9.8 trillion on crop production between now and 2050. Virtually every economic analysis to date does not include the agricultural gains. There are also benefits in health, as warmer winters reduce mortality by more than hotter summers increase deaths. The real economic question then, is “Can we afford to slow CO2 emissions at all?”
While there are negative externalities projected by some climate modelers, their models are unvalidated, proven wrong, and based on unsupported assumptions about clouds and humidity. Compare that to the agricultural gains, which are not just demonstrated in laboratory greenhouses, but confirmed in the field, and with global satellite estimates of increased biomass.
Obviously, the only sensible thing to do at this point is continue our emissions of carbon dioxide. At some point in the future, after climate models start working, and proper calculations of externalities can be estimated, we will probably want to tax projects which sequester CO2 and remove it from the atmosphere.
My only hesitation is that if Murry Salby is right, Big-Oil don’t have a lot to do with it. We can thank Mother Nature instead. Scrap that tax too. ;- )
How much better does it get?
A 300ppm increase in CO2 would increase crop mass by between 4% – 77%. (It doesn’t matter much to your melons, but is marvelous for your carrots and pretty darn good from your grapes too.) Most crops would be 30-40% larger. (I guess the Greens will be excited we won’t need to raze so many forests to convert to cropland, right?)
Despite this basic, well-known research being replicated-ad-nauseum no one has really thought to count this as a serious cost benefit until now.
Absent (or severely underrated) in nearly all social cost of carbon (SCC analyses), however, is the recognition and incorporation of important CO2-induced benefits, such as improvements in human health and increases in crop production. With respect to human health, several studies have shown that the net effect of an increase in temperature is a reduction in sickness and death rate (Christidis et al., 2010; Wichmann et al., 2011; Egondi et al., 2012; Wanitschek et al., 2013; Wu et al., 2013). A warmer climate, therefore, is less expensive in terms of health care costs than a colder one. With respect to crop production, literally thousands of laboratory and field studies have documented growth-enhancing, water-conserving and stress alleviating benefits of atmospheric CO2 enrichment on plants (Idso and Singer, 2009; Idso and Idso, 2011). For a 300-ppm increase in the air’s CO2 content, such benefits typically enhance herbaceous plant biomass by around 30 to 35%, which represents an important positive externality entirely absent from today’s state-of-the-art SCC calculations.
It is only food, after all.
However, this is serious money
So the by-product of fossil fuels supposedly made rice growers richer by around $600 billion in the last 50 years?
(Not to mention that a few people got fed as well.)
Is that a hockeystick I see?
Hands-up who wants to go back to 350ppm?
Everyone I guess — except for the farmers and people who eat …food.
Thanks to pollution there is more food available per capita today. (Orwell didn’t see that one coming.)
Who is the denier? Civilization depends on carbon.
The science behind this is well established and uncontested. The fertilization effects of carbon dioxide have been known for 200 years.
Numerous studies conducted on hundreds of different plant species testify to the very real and measurable growth-enhancing, water-saving, and stress-alleviating advantages that elevated atmospheric CO2 concentrations bestow upon Earth’s plants (Idso and Singer, 2009; Idso and Idso, 2011). In commenting on these and many other CO2-related benefits, Wittwer (1982)wrote that “the ‘green revolution’ has coincided with the period of recorded rapid increase in concentration of atmospheric carbon dioxide, and it seems likely that some credit for the improved [crop] yields should be laid at the door of the CO2 buildup.” Similarly, Allen et al. (1987) concluded that yields of soybeans may have been rising since at least 1800 “due to global carbon dioxide increases,” while more recently, Cunniff et al. (2008) hypothesized that the rise in atmospheric CO2 following deglaciation of the most recent planetary ice age, was the trigger that launched the global agricultural enterprise.
In a test of this hypothesis, Cunniff et al. designed “a controlled environment experiment using five modern-day representatives of wild C4 crop progenitors, all ‘founder crops’ from a variety of independent centers,” which were grown individually in growth chambers maintained at atmospheric CO2 concentrations of 180, 280 and 380 ppm, characteristic of glacial, post-glacial and modern times, respectively. The results revealed that the 100-ppm increase in CO2 from glacial to postglacial levels (180 to 280 ppm) “caused a significant gain in vegetative biomass of up to 40%,” together with “a reduction in the transpiration rate via decreases in stomatal conductance of ~35%,” which led to “a 70% increase in water use efficiency, and a much greater productivity potential in water-limited conditions.”
In discussing their results, the five researchers concluded that “these key physiological changes could have greatly enhanced the productivity of wild crop progenitors after deglaciation … improving the productivity and survival of these wild C4 crop progenitors in early agricultural systems.” And in this regard, they note that “the lowered water requirements of C4 crop progenitors under increased CO2 would have been particularly beneficial in the arid climatic regions where these plants were domesticated.” For comparative purposes, they also included one C3 species in their study – Hordeum spontaneum K. Koch – and they report that it “showed a near-doubling in biomass compared with [the] 40% increase in the C4 species under growth treatments equivalent to the postglacial CO2 rise.” In light of these and other similar findings (Mayeux et al., 1997), it can be appreciated that the civilizations of the past, which could not have existed without agriculture, were largely made possible by the increase in the air’s CO2 content that accompanied deglaciation, and that the peoples of the Earth today are likewise indebted to this phenomenon, as well as the additional 110 ppm of CO2 the atmosphere has subsequently acquired. And as the CO2 concentration of the air continues to rise in the future, this positive externality of enhanced crop production will benefit society in the years, decades, and even centuries to come.
Extra CO2 helps plants cope with drought conditions, and improves plant growth even in situations where soil is poor (e.g. Africa)
In the case of soil infertility, many experiments have demonstrated that even when important nutrients are present in the soil in less than optimal amounts, enriching the air with CO2 still boosts crop yields. With respect to the soil of an African farm where their “genetic and agroecological technologies” have been applied, for example, Conway and Toenniessen speak of “a severe lack of phosphorus and shortages of nitrogen.” Yet even in such adverse situations, atmospheric CO2 enrichment has been reported to enhance plant growth (Barrett et al., 1998; Niklaus et al., 1998; Kim et al., 2003; Rogers et al., 2006). And if supplemental fertilization is provided as described by Conway and Toenniessen, even larger CO2-induced benefits above and beyond those provided by the extra nitrogen and phosphorus applied to the soil would likely be realized.
There are some however who deny basic chemistry, and who appear to have little concern for the hungry or poor people of the world. What kind of world do you want to pass on to your kids? One where billions of dollars is spent trying to pump a harmless fertilizer deep underground, where no plant can grow? In this future, some children grow up to be serfs to pay for the pumping, while other kids die of hunger as corn is fed to cars, and they all lose money making sure the extra fertilizer that might have improved crop yields is not permitted to do so.
On Roy Spencer’s Blog, Roy mulled it over: “E’Gad! How could any by-product of human activity possibly be good?” Meanwhile in comments there, KR wondered about the Green Revolution being forgotten, whether the C3/C4 ratios were considered in the paper, and whether the FACE experiments showing more woody mass and decreased edible mass under CO2 enrichment (is Nitrogen the limiting factor).
Craig Idso replied that KR should read the paper.
His answer in full:
See the actual paper. I give full acknowledgement and recognition to the green revolution in what I refer to as the Techno-intel effect. Look at Figure 3, it shows that for sugar cane yields, the techno-intel effect accounts for between 85 and 95 percent of annual yields. The CO2 effect accounts for the rest.
As for the difference between C3 and C4 responses to CO2, that is also accounted for in the estimates. Again, read the paper! The CO2 effect is derived from the plant growth database at CO2science.org. These CO2 growth response factors are plant specific.
Your concerns about nitrogen limitation are false: See http://www.co2science.org/subject/n/subject_n.php and scroll down to Nitrogen, Progressive Limitation Hypothesis and view the links there. And as for FACE studies, they tend to UNDERESTIMATE the CO2 effect. See http://www.co2science.org/subject/f/faceartifacts.php
Lastly, as for the claim that the edible portion is decreased, that is not supported by the literature either. Using wheat as an example, where both total biomass and grain biomass responses are reported, the grain biomass is usually HIGHER than the total biomass. See http://www.co2science.org/data/plant_growth/dry/t/triticuma.php
Idso Craig (2013): The Positive Externalities of Carbon Dioxide: Estimating the Monetary Benefits of Rising Atmospheric CO2 Concentrations on Global Food Production , Center for the Study of Carbon Dioxide and Global Change. [PDF]
POST NOTE: ” an additional $11.6 trillion on crop production ” revised by Craig Idso to $9.8 trillion. 24/10/2013