Climate change making younger and shorter treesDate: 30 May 2020 Tags: Climate Change
Rising temperatures, deforestation, development and climate-induced disasters are transforming Earth's forests. Older, bigger trees are being lost at an alarming rate, making the planet's collective forests shorter and younger.
The shift is being driven at different rates by different causes in different places, but the consequences will be global.
Old growth forests absorb and store massive amounts of climate-warming carbon dioxide. They provide habitat for rare and critically endangered species and foster rich biodiversity. And they're disappearing fast.
Researchers found that the world lost roughly one-third of its old growth forest between 1900 and 2015. In North America and Europe, where more data was available, they found that tree mortality has doubled in the past 40 years.
Warming temperatures, wildfires, logging and insect outbreaks were among the many causes of the decline.
To get a broader understanding of how forests are shifting globally though, researchers brought in more than 20 other researchers with varying expertise.
Together, they sifted through more than 160 previous studies about tree mortality and its global causes, applying current satellite data and modelling to create perhaps the most comprehensive look at Earth's shifting forests to date.
Human-driven climate change is also making it difficult for many forests to fully recover from the type of natural disturbances, wind events, flooding or fire that would normally occur.
The researchers did find evidence that increased carbon dioxide in the atmosphere could increase tree growth in some places, but not to an extent where it would outweigh the harm being done by increased temperatures.