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slackingoff2017

The increase amount is debated but higher CO2 levels have caused significant gains in farming efficiency.

http://www.climatecentral.org/news/study-finds-plant-growth-...

I have no disagreement with the claim that higher levels of CO2 increases plant growth. That is a fact. I seriously doubt the 30% claim without compelling evidence, though. Especially for agriculture, where water limits are rarely the concern and we dump fertilizer like it's free.

Actually our use of fertilizer and irrigation makes CO2 level a significant limiter on plant growth rates. CO2 fixation is so expensive that plants adapted to arid environments have developed a better way of doing it, C4 carbon fixation.

I found the study: https://wattsupwiththat.com/2017/04/05/study-suggests-increa...

That's an interesting study but I fail to see that it supports your claim. There's no mention of C4 fixation in the article, nor any claim that CO2 fixation is a significant limiter for agriculture.

The article claims 30% increase in general (not just agricultural), but also does not attribute all that simply to more available CO2.

Your own claim is self-contradicting as you use arid environments as the basis for your claim. Agricultural environments where plants are irrigated are not arid, by definition.

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