Part 1 is an excerpt from my 2021 book,
Sensible Decarbonization: Regulation, Risk, and Relative Benefits in Different
Approaches to Energy Use, Climate Policy, and Environmental Impact
Part1
While the net
effects of CO2 are thought to be negative due to the potentially catastrophic
effects of global warming, there is no doubt that higher atmospheric CO2 has
significant positive effects on plant and food crop growth. That is why it is
used in greenhouses. The evidence for global greening, mostly due to higher
atmospheric CO2 concentrations, is also without doubt. Thus, it helps us grow
more food to support a larger population. While groups such as the CO2
Coalition have taken flack for promoting the benefits of CO2, even some fact-checking
by Facebook, their research is important and should be considered, with
caveats. While some of them may say the net effect of CO2 is positive, that
does not appear to be the case. Hypothetically, if we had the choice to bring
atmospheric CO2 levels back to pre-Industrial times at 280 ppm, should we? How
would that effect plant growth and yields? It is reasonable to assume that the
effect would be quite negative in terms of yields, plant health, and reduction
in ability to absorb more carbon. Abundant CO2 allows plants to increase their
rate of photosynthesis by removing carbon from the air more efficiently while
also conserving water. NASA satellite data indicates that a quarter to a half
of Earth’s vegetated lands have had increases in leaf volume on trees and other
plants since 1980 and more is expected as atmospheric CO2 continues to rise.
Recent
discoveries at the bottom of a lake in New Zealand recovered leaves from the
Miocene Era (23.3 million years ago to 5.3 million years ago) that retained
their original chemical compositions and thus allowed scientists to estimate
that atmospheric CO2 concentrations were indeed high then as thought, although there
was previously no direct evidence. Proxies from marine organisms suggested that
CO2 concentrations then were only 300ppm, which was perplexing, but these new
direct measurements suggest that CO2 was at about 450ppm, which better matches
other data. Average global temperatures during the Miocene are thought to have
been 3-7 deg C higher than today and this new data matches better with those
estimated temperatures. The plants’ efficiency at extracting CO2 from the air
and preserving water allowed them to grow better in marginal drier areas. A
2016 paper concluded that globally there has been a 14% increase in greening
over the previous 30 years using satellite leaf area index records and global
ecosystem models. They suggested that the CO2 fertilization effect accounts for
70% of the greening. Climate change itself, making colder and high elevation
areas more habitable for plants, is suggested to account for 8% of the increase
in greening.[1] [2]
Matt Ridley
writes that “Global greening has affected all ecosystems – from arctic
tundra to coral reefs to plankton to tropical forests – but shows up most
strongly in arid places like the Sahel region of Africa, where desertification
has now largely reversed. That is because plants lose less water in the
process of absorbing carbon dioxide if the concentration of carbon dioxide is
higher. Ecosystems and farms will be less water-stressed at the end of this
century than they are today during periods of low rainfall” That is good
news. I wrote a paper on desertification at the edges of the Sahara as an
undergrad in the late 1980’s for a geography class when it was a much bigger
problem being exacerbated by overgrazing and deforestation. More flora means
more food for fauna, including humans. Ridley notes that detractors, instead of
acknowledging the benefits often say that global greening is temporary and that
it will reverse late in the century based on a few models which he says are at
the extreme end of possibilities and not at all likely.[3]
There are some potential downsides to accelerated plant growth due to CO2. Some
scientists think based on new research that faster tree growth may mean shorter
lifespans of some trees and that faster growing trees will win out in competition
for light in high-CO2 air. Slower growing trees will be disadvantaged but the
fast-growing trees may be more vulnerable to droughts, heat, and storms, they
suggest.
A study by the
University of Michigan also suggests that the carbon uptake of northern
cold-climate forests is already beginning to increase. Interestingly the study
shows that since 1980 Siberian cold-climate forests absorbed four times more
carbon seasonally than other forests at similar latitudes. This shows that
different forests at similar latitudes can have very different carbon uptake
characteristics. Species of trees and plants matters as does seasonal weather. Warmer
temperatures in the north of the northern hemisphere may be aiding higher carbon
uptake in Siberia but that does not appear to be the case in northern North
America. Still, most scientists see that global greening through net greening will
continue to increase terrestrial uptake of carbon even if at some point those
other factors will slow the increase.[4]
Part 2 – Ag Research, Ag-Intensification Through
Biotech, and New Data on Global Food Production
A recent short
news story by NPR lamented that government funded agricultural research has
been dropping in recent years but ag research funded by private industry has
been growing. It was noted the annual government funding is at about $5
billion, on par with funding in the 1970’s. China’s government ag research funding
has surpassed that of the US and Brazil is not far behind. Even though private research
funding is growing, detractors say that it will be skewed towards making profit.
I think that concern is overblown as much research is focused on increasing
yields and developing drought-tolerant crops.[5]
Meanwhile,
food production is up and surpassing records. We are still succeeding in feeding
an ever- growing population, despite the failed predictions half a century ago
that we would not be able to feed the world. Technology, beginning with the
Green Revolution allowed us to develop crops that could thrive under different
circumstances and to keep the world fed. The hard work of Norman Borlaug and
others is amazing to read about and should inspire us. Agricultural
intensification through biotechnology innovations also offers much hope to increase
yields further and develop new and better crops. Borlaug’s selective breeding,
his “shuttle breeding” that allowed faster breeding in some places in order to
speed up selection, combined with synthetic fertilizer, were two major
innovations that stemmed famine. Plant diseases could be breeded out. The Green
Revolution spurred agricultural intensification – more food from heathier
plants using smaller amounts of land. Using smaller amounts of land = more
biodiversity preserved. Higher yields also mean less energy input per unit of
food which means less pollutants and CO2 emissions per unit of food. It also
means less soil loss, less water consumption, and often less herbicide use per
unit of food. Since organic farming uses more land than modern mechanized
farming one could easily argue successfully that modern mechanized farming is
more sustainable than organic farming, especially if you add in soil and soil
carbon preserving techniques like no-till or low-till farming that have been
more suitable to biotech-enabled mechanized farming than organic farming.
Genetically engineered Bt crops have reduced pest problems in fields where they
are grown as well as in nearby fields not using them.
Matt Ridley
wrote in his 2020 book, How Innovation Works: And Why It Flourishes in
Freedom, “There is no doubt that extraordinary improvements in the yield,
nutritional quality, and environmental impact of food crops is going to be
possible in the future.” New biotech solutions on the horizon include
increasing photosynthesis efficiency, inserting nitrogen-fixing bacteria into
the cells of plants, increasing effectiveness of herbicides and pesticides,
increasing nutrition of crops, and increasing yields further.[6]
Many new innovative agricultural solutions on the horizon involve gene-editing
through CRISPR. Experiments are ongoing to engineer trees with vastly improved
uptake of atmospheric CO2, mainly through faster and better growth, although these
ideas are still considered controversial.
Although much
of the rhetoric around climate change suggests that it will negatively affect
food production, that does not seem to be the case overall. After severe
disruptions in wheat production and availability on the global market due to
the Russian invasion of Ukraine, several other wheat-producing countries have
stepped up yields considerably. More wheat acreage has been planted in several countries
to make up for the shortfall and the past year’s weather has helped as well.
Winter wheat production is up in the US and the UK. Zimbabwe and India (a major
wheat producer) report record yields. China, the world’s largest wheat
producer, also has reported higher yields. CO2 Coalition Research Associate
Vijay Jayaraj points out why this might be the case:
“Greater warmth has allowed for longer growing seasons
and the cultivation of a wider variety of crops. Higher CO2 concentrations have
helped plants to photosynthesize more efficiently, resulting in increased
growth and crop yields.”[7]
So, like it or not, higher atmospheric CO2 and a bit of
warming leading to slightly longer growing seasons probably do allow us to
produce more food.
[1] Fossil Leaves Show High Atmospheric Carbon Spurred
Ancient ‘Global Greening’ – by Earth Institute at Columbia University.
Archaeology News Network, Phys. Org. Aug. 8, 2020 https://phys.org/news/2020-08-fossil-high-atmospheric-carbon-spurred.html
[2] Zhu, Zaichun, etal., 2016. Greening of the Earth and
its drivers. Nature Climate Change 6, 791-795 https://www.globalcarbonproject.org/global/pdf/Zhu_2016_Greening%20of%20the%20Earth%20and%20its%20drivers.NatureCC.pdf#:~:text=%20%20%20Title%20%20%20Greening%20of,Created%20Date%20%20%204%2F15%2F2016%207%3A23%3A12%20PM%20
[3] Ridley, Matt, July 8, 2019. Ridley: Rejoice, the
Earth is Becoming Greener. Human Progress. https://www.humanprogress.org/ridley-rejoice-the-earth-is-becoming-greener/
[4] France-Presse, Agence, September 9, 2020. Too Much
CO2 Has an Unnerving Effect on the World’s Trees, New Study Finds. Science
Alert. https://www.sciencealert.com/too-much-co2-makes-trees-live-fast-and-die-young-says-study
North American
cold-climate forests are already absorbing less carbon, study shows – by
University of Michigan, in Phys.org, Aug. 17, 2020. https://phys.org/news/2020-08-north-american-cold-climate-forests-absorbing.html
[5]
Agricultural research funding has dropped, impacting the fight against climate
change. NPR. Weekend Edition. January 22, 2023. Agricultural research funding has dropped, impacting the
fight against climate change : NPR
[6]
How Innovation Works: And Why it Flourishes in Freedom. Matt Ridley. Harper
Collins. 2020.
[7]
Here’s Why The World Is Producing More Food. Vijay Jayaraj. CO2 Coalition.
January 23, 2023. Here’s Why The World Is Producing More Food - CO2 Coalition
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