Summer Drought limits the positive effects of CO2 and heat on plant growth in future climate

[OKIsItJustMe]

http://www.risoe.dtu.dk/News_archives/News/2011/0817_CLIMAITE_report.aspx?sc_lang=en

17.08.2011

Summer Drought limits the positive effects of CO₂ and heat on plant growth in future climate

Although the rain this summer has been pouring down over Denmark, most scientists agree that global temperature increases will intensify periods with summer drought already in 2075. The large scale project CLIMAITE, led by Risø DTU, has published its first synthesis paper in the renowned journal Global Change Biology, and the conclusion is perhaps a little surprising that the predicted increase in plant growth, due to more CO₂ in the atmosphere is noticeably limited when combined with higher temperatures - and especially summer droughts.

In contrast to the increased growth in plants that scientists have often seen in studies with elevated CO₂, the first synthesis paper on the comprehensive CLIMAITE project shows that the combination of summer drought and potential plant growth-promoting factors such as higher temperatures and increased CO₂ together limit the effect of CO₂ increased plant growth significantly.

"When you've previously seen a significantly higher plant growth at elevated CO₂ concentrations, it is typically because it has been controlled studies, where only the CO₂ concentration was changed. We fundamentally had the theory that you have to look at the combination of the different climate variables, since the plants in the future will be exposed to multiple changes simultaneously, "explains Klaus Steenberg Larsen, who is a researcher in the Biosystems Division at Risø DTU and lead author on the scientific paper.

CLIMAITE is a Danish research center that investigates how climate change, as they probably appear in 2075, affects biological processes and ecosystems in nature. Data from the first two years are underlying the scientific paper, and results clearly indicate that we will not get the predicted increase in plant growth in our latitudes in the future.

…

http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2486.2010.02351.x/abstract

[NickB79]

1. Plants can't absorb CO2 without water to grow? File this under "No Shit"

[OKIsItJustMe]

2. The thing is…

…plenty of “deniers” have been saying that that increased CO₂ would be a “good thing™” for plant growth.

http://www.newscientist.com/article/dn11655-climate-myths-higher-co2-levels-will-boost-plant-growth-and-food-production.html


This study provides concrete, experimental evidence to say, “It just ain’t so.”