Fact brief – Is more CO2 a good thing because it’s plant food?

Posted on 12 October 2024 by Guest Author

Skeptical Science is partnering with Gigafact to produce fact briefs — bite-sized fact checks of trending claims. This fact brief was written by Sue Bin Park from the Gigafact team in collaboration with members from our team. You can submit claims you think need checking via the tipline.

Is more CO2 a good thing because it’s plant food?

While CO₂ is necessary for plant growth, the negative impacts of climate change, driven by man-made CO₂ emissions, far outweigh short-term productivity gains.

Plants need a balance of CO₂, sunlight, water, and nutrients. Though more CO₂ can initially boost growth, rising temperatures, disease vulnerability, shifting land fertility, and increased water demands offset these benefits.

The UN warns that global crop yields could decline by up to 30% by 2050, while a 2017 meta-analysis linked each degree of warming to a 3-7% yield loss for key crops like corn and soybeans. Losses are also attributed to increased disease pressure from altered climates.

Raised CO₂ levels can also lower food quality. Reviews found reduced levels of essential nutrients in staple crops, while protein concentrations in grains like wheat and rice dropped by 10-15%.

The rapid human-induced accumulation of CO₂ is producing more negative than positive consequences—for plants and the Earth at large.

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This fact brief is responsive to conversations such as this one.

Sources

Columbia Climate School How Climate Change Will Affect Plants

Scientific American Ask the Experts: Does Rising CO2 Benefit Plants?

Global Commission on Adaptation ADAPT NOW: A GLOBAL CALL FOR LEADERSHIP ON CLIMATE RESILIENCE

National Academy of Sciences Temperature increase reduces global yields of major crops in four independent estimates

Nature Climate change impacts on plant pathogens, food security and paths forward

Science Carbon dioxide (CO2) levels this century will alter the protein, micronutrients, and vitamin content of rice grains with potential health consequences for the poorest rice-dependent countries

Global Change Biology Effects of elevated CO2 on the protein concentration of food crops: a meta-analysis

About fact briefs published on Gigafact

Fact briefs are short, credibly sourced summaries that offer “yes/no” answers in response to claims found online. They rely on publicly available, often primary source data and documents. Fact briefs are created by contributors to Gigafact — a nonprofit project looking to expand participation in fact-checking and protect the democratic process. See all of our published fact briefs here.