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Comment by slackingoff2017 | Hacker News Reader

slackingoff2017

Earth has had CO2 levels far higher than currently in the geologically recent past. We will run out of fossil fuels well before we destroy the planet.

The biggest effect of global warming so far is arguably positive. Plants are making good use of higher CO2 levels and it's estimated that farming yields have increased 30% in the last century from this faster plant growth.

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The biggest effects are that it's getting goddamned hot in places that used to be temperate and that the ice caps are melting. Neither of these are positive and your 30% higher plant growth claim is undoubtedly BS. Most improvements to agriculture have come from fertilizers, the production of which contribute to global warming.

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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