Recent scientific research confirms that trees are growing larger and more robust thanks to rising carbon dioxide (CO2) levels, a fact conspicuously absent from doomsday environmental reporting.

Over the past four decades, global vegetation has surged by at least 15 percent. This surge has been fueled by CO2 fertilization, where plants absorb more of the gas they need to thrive. Far from being a pollutant, CO2 is nature's plant food and the Earth is responding with a dramatic greening effect.

Plants – including trees – have evolved over millions of years to flourish in atmospheric CO2 levels far higher than today's 420 parts per million (ppm). In fact, prehistoric CO2 concentrations were three times current levels and vegetation thrived. Modern experiments confirm that when CO2 increases, so does plant growth.

The Birmingham Institute of Forest Research has been conducting a landmark study since 2017, exposing 180-year-old oak trees in Staffordshire, England, to elevated CO2 levels of 550 ppm. The results? A 10 percent boost in growth rates compared to trees in normal conditions, producing an extra 1.7 tons of dry matter per hectare annually. (Related: CO2 is the GREENING molecule: New study shows how elevated CO2 levels increase vegetation growth and WATER AVAILABILITY in the Northern Hemisphere.)

The CO2 effect: Global evidence of greening
One of the most striking findings is how efficiently trees use extra CO2. Mature oaks in the study increased their photosynthesis rates by up to 33 percent, especially in strong sunlight.

Unlike leaves, which decompose quickly, wood stores carbon long-term, meaning bigger trees also mean more carbon sequestration. Even more surprisingly, the trees maintained stable carbon-nitrogen ratios, suggesting they adapt seamlessly to higher CO2 by absorbing more nutrients from the soil.

This phenomenon isn't limited to England. A long-term experiment in North Carolina's Duke Forest found that pine trees exposed to an extra 200 ppm of CO2 grew up to 27 percent larger annually, with photosynthesis rates spiking by 50 percent.