Thread by @ncdave4life

@Jeremy_Williams @NatGeo @newscientist That's wrong, Jeremy. Do you imagine that droughts are something new? Do you know how it was that the Israelites ended up in bondage, in Egypt?

NOW most famines are caused by conflict. But when CO2 levels were <300 ppmv most famines were caused by drought.

@Jeremy_Williams @NatGeo @newscientist When you read that "Madagascar is going through its worst drought in 40 years," you should realize that means they had an EVEN WORSE drought back when CO2 level was only about 340 ppmv (75 ppmv lower than now).

nytimes.com/1981/03/26/wor…

@Jeremy_Williams @NatGeo @newscientist Droughts have always happened, but manmade climate change has NOT made them worse or more frequent. That's not speculation, and not legitimately debatable. It is a measured fact:

nature.com/articles/sdata…

@Jeremy_Williams @NatGeo @newscientist If you should suspect that the starting point for that graph is cherry-picked to hide an increase, it's actually just the opposite. The graph starts just AFTER the African megadrought which was the subject of that 1981 NY Times article.

@Jeremy_Williams @NatGeo @newscientist You can see the same thing in the U.S. data: contrary to climate activists' claims, droughts are NOT worsening. Blaming CO2 emissions for droughts is propaganda, not science.

ncdc.noaa.gov/temp-and-preci…

@Jeremy_Williams @NatGeo @newscientist Instead, elevated CO2 (eCO2) has substantially MITIGATED drought impacts, and thus helped reduce the frequency & magnitude of weather-related famines. That's because higher CO2 levels reduce plants' water requirements, making them more drought-resilient.

@Jeremy_Williams @NatGeo @newscientist Here's a relevant paper:
sciencedirect.com/science/articl…

EXCERPT: "There have been many studies on the interaction of CO2 and water on plant growth. Under elevated CO2, less water is used to produce each unit of dry matter by reducing stomatal conductance."

@Jeremy_Williams @NatGeo @newscientist The benefits of eCO2 for crops are settled science.

The benefits are large under ideal growing conditions, and even larger under drought stress.

Sadly, most climate activists know nothing about agronomy, and most climate scientists never study it.
journals.plos.org/plosone/articl…

@Jeremy_Williams @NatGeo @newscientist Climate activists either don't know or don't care about how eCO2 reduces famines, and how "net zero" CO2 emissions would surely worsen famines, and kill millions of people.

ncbi.nlm.nih.gov/pubmed/26929390

@Jeremy_Williams @NatGeo @newscientist ncbi.nlm.nih.gov/pubmed/26929390

@Jeremy_Williams @NatGeo @newscientist The importance is impossible to overstate. Compare:

● Covid-19 has killed ≈0.05% of world population, so far.

● 1918 flu pandemic killed ≈2%.

● WWII killed ≈2.7%.

● The global drought & famine of 1876-78 killed ≈3.7%, when CO2 level (from ice cores) was ≈289 ppmv.

@Jeremy_Williams @NatGeo @newscientist Elevated CO2 (eCO2) increases crop yields through "CO2 fertilization"

AND

eCO2 makes plants more water-efficient & drought-resilient. eCO2 reduces water requirements, which helps mitigate drought damage, preventing or reducing drought-triggered famines.

@Jeremy_Williams @NatGeo @newscientist @rattibha @threadreaderapp @threader_app please unroll or compile this.