If we could get a whole new continent—equal to twice the size of the continental United States—of vegetation by spending, say, $100 billion, would that be a good deal?
How would we go about answering that?
Well, we might start by noting that the total value of crops raised in the U.S. in 2016 was about $143.4 billion. That’s for one year. And it’s from just about 18 percent of all U.S. land.
But we’re talking about adding a continent of vegetation double the size of the United States, or 11 times as much land as we cultivated last year. At a one-time cost of $100 billion.
Sounds like a bargain to me.
But wait! The deal’s actually a whole lot better. We got that new continent’s worth of vegetation at a price of—nothing.
How?
Economists refer to costs (like pollution) of economic activity that aren’t borne by producers as externalities, or, to be specific, negative externalities. Benefits that aren’t borne by producers are also externalities—positive externalities. We might call such a positive externality an “anti-pollutant.”
All that increased plant growth around the world is a positive externality from all our carbon dioxide emissions. And its value is simply enormous.
That makes CO2 an amazing anti-pollutant. Yes, it has a minor, perhaps immeasurably small upward effect on global average temperature (perhaps around 0.5–2.0 degrees C for every doubling of its concentration).
Viscount Matt Ridley, a scientist and member of the U.K. House of Lords Science and Technology Select Committee, commented on this to Julie Kelly of National Review:
This is a huge global phenomenon, which is bringing enormous financial benefits to agriculture. That means we have a genuine benefit to carbon dioxide that surely must be taken into account if you are calculating the social cost of carbon. Given that we are not seeing any clear impact on droughts, floods, or storms, it is very hard to argue that there have been net negatives to carbon from climate change so far. In fact, there have clearly been net benefits.
By the way, it’s not just “climate skeptics” who point to the greening of planet earth by CO2. Even NASA made a big deal of the story, reporting that after modeling the contributions of CO2, nitrogen fertilization, and various climate changes over the period, researchers concluded that 70 percent of the greening was attributable to CO2, with the next-biggest contributor, nitrogen, accounting for only 9 percent. It depicts the story in this brief video:
This isn’t a brand new recognition. The Center for the Study of Carbon Dioxide and Global Change produced videos in 1992, The Greening of Planet Earth, and 1998, The Greening of Planet Earth Continues, that explained how this works, but at the time there wasn’t a whole lot of data to demonstrate that what made sense in theory was actually happening. Now there is. It’s time for a sequel.
Sarah Visscher says
Dr. Beisner, I wonder if you could comment on David Suzuki’s latest Science Matters column that just ran in our weekly paper on this same topic. He claims, “Several studies have found that, even when increased CO2 makes plants grow bigger and faster, it reduces proteins and other nutrients and increases carbohydrates in about 95% of plant species, including important food crops such as barley, rice, wheat and potatoes. A 2014 Harvard School of Public Health study, published in Nature, found that increased CO2 reduced the amount of valuable minerals such as zinc and iron in all of them. Another study, by Irakli Loladze at the Catholic University of Daegu in South Korea, looked at 130 species of food plants and found increased CO2 caused calcium, magnesium, potassium, zinc and iron concentrations in plants to decline by an average of 8%, while sugar and starch content increased.” Thanks!
Megan Toombs says
Thanks for the question, Sarah. We went directly to one of the world’s leading experts on the subject, Dr. Craig Idso of the Center for the Study of Carbon Dioxide and Global Change, and he replied:
It is fair to say that a decline in nutrition (usually nitrogen, but also other micro and macronutrients) has been observed in multiple CO2-enrichment studies. However, such declines are generally small, amounting to only a very few percent (usually below 5 percent). What you do not hear in these articles is the fact that this finding of a nutrient reduction in concentration is not uniform and does not always occur. In fact, the response often differs by plant cultivar such that you get a range from negative to positive values on nutrition under elevated CO2. Nutrition content, as opposed to concentration, however, is almost always unanimously increased in CO2 enrichment studies. The increase in roots allows the plants to explore more soil and gather a greater nutrient content that is then distributed among the CO2-enhanced biomass, where it is sometimes diluted (relative to ambient) because the growth enhancement is so large. When it is diluted, one can view it in another light, that the plants become more efficient in using nutrients, i.e., their nutrient use efficiency increases.
So what is the impact of this change on human nutrition? Not much. In almost all cases, the decline in nutrient concentration can be overcome such that the USDA recommended daily allowance of the nutrient can be met by taking a multi vitamin or one or two extra bites of the food being ingested, but generally people meet and exceed the necessary daily allowance of these nutrients by such an amount that the few percentage point decline in plants will never matter. And if you live in the third world, you can take an extra bite or two to make up the difference. After all, you could use it!
What is more, other studies have shown that the nutrition deficit can be fully ameliorated by adding the right type/mix of fertilizer at the appropriate time. When these facts are considered, the nutrition concentration issue becomes a non-issue. It is something the alarmists cling to and tout in desperation.
For more information, go to http://www.co2science.org/subject/n/subject_n.php and click on the links for Nutrition, Nutrients x CO2 Effects on Plants, Nutrient Acquisition and Nitrogen Use Efficiency. Also go here: http://www.co2science.org/subject/h/subject_h.php under the heading Health Effects of CO2 (Health Promoting Substances). Or, here are a few direct links:
http://www.co2science.org/articles/V20/jul/a5.php (this is one that shows Nitrogen source supply impacts the protein response from negative to positive)
http://www.co2science.org/articles/V19/sep/a21.php (shows the varied response by genotype for barley)
http://www.co2science.org/articles/V19/sep/a7.php (one on maize)
http://www.co2science.org/articles/V20/sep/a5.php (one on soybean)
http://www.co2science.org/articles/V20/sep/a5.php (another on soybean)
http://www.co2science.org/articles/V20/sep/a3.php (one on lettuce)
http://www.co2science.org/articles/V5/N42/EDIT.php (this is a good essay written a few years back on protein)
http://www.co2science.org/subject/p/protein.php (more articles archived about protein)
http://www.co2science.org/subject/n/nutrition.php (a section on Nutrition)
http://www.co2science.org/articles/V5/N32/B1.php (one on Vitamin C)
http://www.co2science.org/subject/a/antioxidants.php (a large group of papers on antioxidants)
http://www.co2science.org/subject/h/co2healthpromoting.php (a grouping of papers on the effect of various substances in plants beneficial to human health)
http://www.co2science.org/subject/h/co2healthmedicinal.php (additional papers on medicinal properties in plants under elevated CO2)
http://www.co2science.org/articles/V12/N49/B3.php (on micronutrients)
A perusal of the papers cited in the reviews above will make it clear that CO2 is clearly beneficial to humans on multiple levels and the micronutrient/nutrition scare is just that – a scare.