Tropical rainforests, the lush ecosystems that house half of the world’s animal and plant species, are teetering on the brink due to the impacts of climate change, according to a new study. Scientists, using data collected from the International Space Station (ISS), have found that rising temperatures caused by climate change are pushing tropical forests beyond their limits. They warn that if temperatures rise by just 4 degrees Celsius, these vital ecosystems could collapse, leading to devastating consequences for the planet’s climate systems and biodiversity.
The study focused on the critical temperatures at which photosynthesis, the process by which plants convert sunlight into energy, starts to fail in tropical trees. Currently, only 0.01% of all leaves in tropical forests surpass this critical temperature each year. However, as temperatures continue to rise, a growing percentage of tree leaves are approaching this maximum threshold for photosynthesis. The average critical temperature for photosynthetic failure is 46.7 degrees Celsius (116 degrees Fahrenheit).
To assess the temperatures in tropical forests, scientists relied on data from the Ecosystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS) sensor and ground measurements made from infrared-sensing pyrgeometers. Their findings revealed that temperatures in the canopy of tropical forests averaged around 34 degrees Celsius (93.2 degrees Fahrenheit), with a small proportion exceeding 40 degrees Celsius (104 degrees Fahrenheit). Every season, 0.01% of leaves in these forests exceed the critical temperature, potentially leading to their deaths.
The study’s authors note that while this percentage may seem small, it could increase rapidly as temperatures continue to rise. The researchers conducted laboratory leaf experiments, which confirmed that temperatures around the leaves can reach up to 8 degrees Celsius (14.4 degrees Fahrenheit) higher than the air temperature. When the air temperature around the leaves increases by 3.9 degrees Celsius (7 degrees Fahrenheit), the most exposed leaves begin to close their water-carrying stomata, resulting in their deaths. This domino effect could lead to the death of entire branches and eventually whole trees.
Tropical rainforests play a crucial role in the Earth’s ecosystem. They cover around 6% of the planet’s surface and provide habitats for millions of species. Additionally, they store one-fifth of the world’s fresh water and produce 32% of the planet’s oxygen while absorbing billions of tons of carbon dioxide, helping to stabilize global climates.
While the study highlights the potential tipping point for tropical forests, the scientists remain optimistic that there is still time to take action. They emphasize the need to curb greenhouse gas emissions to prevent further temperature increases and preserve these invaluable ecosystems. The collapse of tropical rainforests would not only have devastating ecological consequences but also exacerbate climate change, endangering the planet and its biodiversity.
In conclusion, the study provides a stark warning about the impacts of climate change on tropical rainforests. As temperatures continue to rise, these vital ecosystems are approaching their limits, and a tipping point could lead to their collapse. Urgent action is needed to reduce greenhouse gas emissions and protect the invaluable biodiversity and climate-stabilizing functions of tropical rainforests.
