Our friends at the CO2 Coalition have come out with a new report entitled “Nutritive Value of Plants Growing in Enhanced CO2 Concentrations (eCO2).” It is a comprehensive report very useful as a reference to counteract the humongous hyperbole of those who mistakenly view CO2 as a planet killer. The 33-page analysis is a bit technical in parts, but the Introduction and Summary are easily digested and I have included both below, along with three of my personal favorites among the outstanding graphics presented.
INTRODUCTION
The concentration of atmospheric carbon dioxide (CO2 ) has increased from a preindustrial value of about 280 ppm (parts per million by volume) to about 425 ppm in the year 2024. Much of this increase has come from burning fossil fuels. Despite many years of claims that increasing concentrations of CO2 are an “existential threat” to life on Earth (a recent descriptor being “global boiling”) one cannot identify any harm that has been done. In fact, the only clear result of increasing CO2 has been an overall greening of the Earth and increasing productivity of agricultural and forest crops.
For example, in a recent paper, Taylor and Schlenker (2023) state:
"We consistently find a large CO₂ fertilization effect: a 1 ppm increase in CO₂ equates to a 0.4%, 0.6%, 1% yield increase for corn, soybeans, and wheat, respectively."
Fig. 1 shows the dramatic increase of global food production over the past century. Major factors in this increase have been growing concentrations of atmospheric CO2, which is “plant food,” major improvements of crop varieties, and increased use of mineral fertilizers that provide adequate levels of nitrogen, phosphorus and other elements in soil for optimal plant growth.
The evidence for greening of the Earth from eCO2 is now too obvious to deny. This is an embarrassment to the large and profitable movement to “save the planet” from “carbon pollution,” a/k/a CO2. If CO2 greatly benefits agriculture and forestry and has a small, benign effect on climate, it is not a pollutant at all.
In recent years, many research groups have shown that there are modest changes in the nutritional value of crops grown in elevated CO2 concentrations. Media promoters of climate alarmism have seized on these results to further demonize CO2 . In this paper we explain why the nutritional value of our more abundant crops can and will remain high as atmospheric CO2 concentrations increase toward values more representative of those existing throughout most of Earth’s history.
SUMMARY
The significant enhancement of plant growth due to increasing CO2 in the atmosphere is often accompanied by a slight dilution of some nutrients, notably nitrogen, in plant tissues if no attempts are made to make up for the increased demands for these nutrients with appropriate fertilizers.
However, we have shown that the deficiencies in nutrients, and especially nitrogen, caused by eCO2 are small, compared to the nutrient shortages that agriculture and livestock face because of natural phenomena, such as severe soil fertility differences, nutrient dilution in plants due to more rainfall or irrigation, and even in aging crops.
These problems have been routinely dealt with for generations through adequate fertilization, proper species and cultivar selection, and food supplements for livestock and humans.
Other observed reactions to eCO2 (such as reduced nitrate reductase activity, reduced photorespiration and reduced carotenoid biosynthesis) can be understood as a resource saving response mechanism of the plant metabolism.
Generally, the additional inputs required for the correction of the nutritional deficits are tiny compared to the benefits of the higher photosynthetic rate due to eCO2 and the associated yield increases.
Moreover, there are reports that elevated CO2 favors the accumulation of health-promoting carbon-based secondary metabolites such as antioxidants.
In addition, eCO2 clearly promotes the efficiency of water use in plants and nitrogen fixation in legumes, which adds beneficial nitrogen to terrestrial ecosystems.
Together, these two factors have led to a significant greening of Earth, particularly in arid regions. There is published evidence that gradually rising CO2 levels have caused no additional nutrient deficiencies in the quarter of Earth’s land surface that is covered with mostly arid rangelands, suitable only for grazing animals, and where fertilizer usage is ruled out for economic reasons.
Grazing animals have innate “nutritional wisdom” that enables them to compensate for nutritional deficiencies by selective browsing of higher quality leaves or legumes. In addition, there are other economical ways to compensate for mineral or protein deficiencies in livestock nutrition.
In conclusion, field studies of plant growth with eCO2, and the geological history of CO2 and Earth’s climate show that:
Plants first appeared in the fossil record when atmospheric CO2 levels were much higher than today. Therefore, one can be confident that plants are genetically equipped to cope with the moderate increase in CO2 levels since the beginning of the industrial era and with additional increases of CO2 in the future. The greening of Earth (Fig. 5) is only the beginning of benefits from more CO2 for plants and for healthy and abundant human nutrition.
Today’s low concentration of atmospheric CO2 is not typical of Earth's climate history, and this gaseous trace compound has not determined the fluctuations of temperature in the past and will not in the future.
Man-made CO2 emissions are not capable of triggering dangerous future warming. Its global warming potential is almost saturated.
The numerous desirable and beneficial effects of more CO2 in the atmosphere greatly outweigh “climate-damaging” or “nutrient-damaging” impacts, to the extent that these even exist. There is no “social cost of carbon,” as is unfortunately and incorrectly claimed in numerous recent publications. In fact, there is a social benefit from more CO2 in the air.
Working in conjunction with the essential growth factors of H2O and sunlight, CO2 is the most important nutrient for plants and for all living organisms depending on food chains. For too long, inadequate atmospheric CO2 has been the shortest stave of Liebig’s barrel (see below).
Rising atmospheric concentrations of CO2 have clearly been beneficial for the biosphere, agriculture, humanity, and particularly for global food security at very low additional cost. Still higher concentrations of CO2 will bring additional benefits.
#CO2 #Climate #Greening #Deserts #FoodProduction #Fertilizer
Our current atmospheric CO2 level is around 427ppm - plants need 800-1500ppm for optimal growth, that’s all we need to know about CO2, we are deficient in it - at 150ppm and below plants die, then so do humans