Earth is greening at an unprecedented rate — and rising CO₂ is playing a starring role. NASA satellite data from (1982 to the present) show a quarter to half of Earth's vegetated lands have greened significantly in recent decades. This added leaf area is equivalent to roughly twice the continental United States. CO₂ fertilisation explains about 70% of the effect, according to key studies (Zhu et al, 2016 in Nature Climate Change).
China and India are leading the way—China through massive forest conservation and expansion (about 42% of its contribution), while India does it via intensive cropland management. Together, they account for around one-third of the global net increase in leaf area, despite covering only 9% of vegetated land.
Global crop yields for staples like wheat, rice and maize have surged since the 1960s (often 200–300% overall, via the Green Revolution). CO₂ fertilisation contributes significantly—estimates show 10–20% or more in some analyses boosting photosynthesis, especially in C3 plants (wheat, rice) by 20–50% at elevated levels.
Famine deaths have also dropped dramatically as the population has doubled, thanks to better yields, distribution and technology. But the CO₂ 'windfall' has helped to make food more abundant. Every 100 ppm rise in CO₂ can boost plant growth by 25–50% in favourable conditions. Many studies point to optimal ranges around 600–1200 ppm for peak growth in controlled settings (diminishing returns for some crops). We're at around 427 ppm now, which is still well below saturation for most plants.
The picture isn't all positive: rising temperatures and nutrient limits may offset some benefits for staple crops (heat stress affects wheat/rice/maize). But the greening boom—70% orbit driven by CO₂, plus human efforts in places like China/India—show CO₂ to be a net boon for terrestrial life so far.