Dave Burton@ncdave4life
Dave BurtonJun 18, 2024
7 tweets
1/7. This PBS piece is extremely misleading. Elevated CO2 greatly improves crop yields, and it mitigates drought impacts, by improving plants' water use efficiency (WUE) and drought resilience. See:
masterresource.org/carbon-dioxide
I asked ChatGPT to explain the mechanism by which agronomists have found that elevated CO2 improves crops' WUE and drought resilience. It did a good job:
ββββββ ββ
ββββββ ββ ββββββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββ ββββββ ββκ§κ§
In agronomy, the effects of elevated CO2 on plant water use efficiency and drought resilience are extensively studied. One of the key mechanisms through which elevated CO2 levels improve water use efficiency is by reducing stomatal conductance and, consequently, water loss through transpiration.
Stomata are small pores on the surface of plant leaves that regulate gas exchange, including the uptake of CO2 for photosynthesis and the release of water vapor through transpiration. When CO2 levels are elevated, plants can maintain the same or higher rate of photosynthesis while reducing stomatal conductance. This reduction in stomatal conductance leads to a decrease in water loss through transpiration without significantly affecting CO2 uptake, resulting in improved water use efficiency.
Several studies have quantified the effect of elevated CO2 on stomatal conductance and transpiration. For example, a meta-analysis published in 2013 (Kimball et al., 2013) found that under elevated CO2 levels, stomatal conductance decreased by an average of 22%, while transpiration decreased by only 17%. This indicates that plants under elevated CO2 levels were able to reduce water loss more efficiently than they reduced CO2 uptake, leading to an overall improvement in water use efficiency.
Improvements in water use efficiency due to elevated CO2 levels can increase plants' drought resilience by allowing them to maintain adequate hydration during periods of water scarcity. This can be particularly beneficial in arid and semi-arid regions where water availability is limited.
Overall, the literature suggests that elevated CO2 levels can improve water use efficiency in plants by reducing stomatal conductance and water loss through transpiration, which can enhance their resilience to drought conditions.
PBS Digital Studios@PBSDS
Sep 28 22
View on Twitter
What will life look like as rivers dry? With global warming continuing, so will droughts. Places will have to live with far less water, which means we are going to need to innovate both how cities and agriculture do business: to.pbs.org/3ChtgLW #Weathered @Maiya May
2/7. Contrary to climate industry propaganda and misinformation from the leftists at PBS, the scientific evidence is compelling that CO2 emissions and rising CO2 levels are beneficial. Here are some relevant papers:
sealevel.info/negative_socia
3/7. The beneficial effects of elevated CO2 are helping make famines rare for first time in human history. If you're too young to understand how important that is, count yourself blessed! Famine used to be a scourge comparable to war & disease.
sealevel.info/learnmore.html
ourworldindata.org/famines
4/7. Droughts kill by hunger, not thirst. They kill by causing crop failures.
sealevel.info/learnmore.html
Or, rather, they used to. The most important thing to know about drought is this: rising CO2 levels mitigate the damage. That's one of the main reasons catastrophic famines are fading from living memory.
Drought incidence has declined only slightly as CO2 levels have risen, but the damage caused by droughts has decreased much more dramatically.
5/7. Ending famine is a Very Big Deal, comparable to ending war or disease. For comparison:
β Covid-19 killed about 0.1% of world population.
β The 1918 flu pandemic killed about 2% of world population.
β WWII killed about 2.7% of world population.
β The near-global drought & famine of 1876-78 killed an estimated 3.7% of world population.
6/7. The scientific evidence is compelling that manmade climate change is modest and benign, and CO2 emissions are highly beneficial. The major harms are all hypothetical, and mostly implausible. The major benefits are proven, measured, and very large:
threadreaderapp.com/thread/1291143
7/7. To understand a contentious, politicized issue like #ClimateChange, you need balanced information. You won't get it from the leftists at @PBS, but I'm here to help:
sealevel.info/learnmore.html
That page has:
β accurate introductory climatology information
β in-depth science from BOTHβ skeptics & alarmists
β links to balanced debates between experts on BOTHβ sides
β accurate information about impacts of CO2 & climate change, such as the effects on crop yields
β links to the best blogs on BOTHβ sides of the climate debate
Dave Burton
Dave Burton@ncdave4life
My preferred pronoun is "harmless data drudge." https://t.co/YTkK6vaHGs Tel: +1 919-481-0098.
Missing some tweets in this thread? Or failed to load images or videos? You can try to .