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I heard that trees also grow faster with more CO2, is that correct? If so, does the faster growing offset CO2, assuming it converts more into trees?
Yes, higher CO2 accelerates tree growth — but forests absorb roughly a third of human emissions, nowhere near enough to offset what we put out.
Why it matters: The same CO2 boost that feeds rice also feeds forests, yet both effects are fragile and fall well short of canceling fossil fuel emissions.
- Controlled FACE (Free-Air CO2 Enrichment) experiments found forest net primary productivity rose ~23% when CO2 reached 550 ppm — the fertilization effect is real.
- In practice the boost often stalls: without extra nitrogen and water, trees hit a ceiling quickly, and some field studies find no meaningful long-term growth increase as atmospheric CO2 has climbed.
- Global forests absorb about 3.5 billion tonnes of carbon per year against human emissions of ~10 billion tonnes — a partial offset, not cancellation.
- That sink is shrinking: extreme fires in 2023–2024 cut forest absorption to roughly one-quarter of its typical annual level, and a 2024 Nature study confirmed the global forest sink has held roughly steady at 3.5 Pg C/yr — it is not expanding to keep pace with rising emissions.
Room for disagreement
- Some researchers stress the fertilization effect as a genuine, measurable win — Yale E360 and FACE experiments show real biomass gains across U.S. tree species. Others, including field ecologists whose work Earth.com covered, argue trees hit nitrogen and water limits fast, so real-world growth gains are far weaker than lab results suggest and shouldn't be counted on as a meaningful carbon offset.
AI-generated with web search — may be wrong. Check the linked sources.
