3/12〕In fact, CO2 emissions mitigate drought impacts. Elevated CO2 helps plants use water more efficiently, by reducing stomatal conductance and transpiration. That's especially helpful in arid regions & during droughts. Here's a paper about corn:
http://www.sciencedirect.com/science/article/pii/S0168192310003163…5/12〕Here's a NASA video about how rising CO2 levels are greening the Earth and causing deserts to retreat:
https://www.youtube.com/watch?v=zOwHT8yS1XI…6/12〕Mitigation of drought damage is a very important benefit of rising CO2 levels, and it is one of the reasons that catastrophic drought-induced famines are fading from living memory, for the first time in human history.
●
https://sealevel.info/learnmore.html?0=droughts#droughts…
●
https://journals.ametsoc.org/view/journals/clim/31/23/jcli-d-18-0159.1.xml?tab_body=fulltext-display… 7/12〕That's a very, very Big Deal. Famine used to be a scourge comparable to war and epidemic, the Third Horseman of the Apocalypse.
●
https://sealevel.info/learnmore.html?0=famine#famine… 8/12〕
https://sealevel.info/learnmore.html?0=madrasfamine#benefits…
For comparison:
● COVID-19 killed about 0.1% of the world's population
● The catastrophic 1918 flu pandemic killed about 2%
● WWII killed 2.7% of the world's population
● But the near-global drought and famine of 1876-78 killed about 3.7% of the world's population.
9/12〕Droughts still happen, of course, but elevated CO2 mitigates the adverse effects of vapor pressure deficit (dryness) on plants. That's why the global greening trend is most pronounced in the driest regions, like the Sahel (southern Sahara).
https://x.com/ncdave4life/status/1753785686279246299…10/12〕ChatGPT did a good job of explaining how elevated CO2 improves plants' water use efficiency and mitigates drought impacts:
“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.”
References:
1. Chun JA, et al. (2011). Effect of elevated carbon dioxide and water stress on gas exchange and water use efficiency in corn. Agricultural and Forest Meteorology, 151(3), pp 378–384.
https://doi.org/10.1016/j.agrformet.2010.11.015….
2. O'Leary GJ, et al. (2015). Response of wheat growth, grain yield and water use to elevated CO2 under a Free-Air CO2 Enrichment (FACE) experiment and modelling in a semi-arid environment. Glob Chang Biol. 21(7):2670–2686.
https://doi.org/10.1111/gcb.12830…
3. Fitzgerald GJ, et al. (2016) Elevated atmospheric [CO2] can dramatically increase wheat yields in semi-arid environments and buffer against heat waves. Glob Chang Biol. 22(6):2269-84.
https://doi.org/10.1111/gcb.13263…
4. Uddin S, et al. (2018) Elevated [CO2] mitigates the effect of surface drought by stimulating root growth to access sub-soil water. PLoS One. 13(6):e0198928.
https://doi.org/10.1371/journal.pone.0198928…
5. Taylor, C & Schlenker, W (2021). Environmental Drivers of Agricultural Productivity Growth: CO2 Fertilization of US Field Crops. National Bureau of Economic Research, no. w29320.
https://doi.org/10.3386/w29320
6. Chen, Xin et al (2024). The global greening continues despite increased drought stress since 2000. Global Ecology and Conservation, Volume 49, 2024, e02791.
https://doi.org/10.1016/j.gecco.2023.e02791….
11/12〕To understand a politicized topic like
#ClimateChange, you need balanced information. I'm here to help:
https://sealevel.info/learnmore.html?0=dummies…
That resource list has:
● accurate introductory climatology information
● in-depth science from both skeptics & alarmists
● links to balanced debates between experts on both sides
● accurate information about impacts of CO2 & climate change, such as the effects on crop yields
● links to the best blogs on both sides of the climate debate