Australia's rainforests become the first in the world to make concerning switch

Lauren Liebhaber, Miami Herald on Oct 20, 2025

By clicking submit, I authorize Arcamax and its affiliates to: (1) use, sell, and share my information for marketing purposes, including cross-context behavioral advertising, as described in our Privacy Policy , (2) add to information that I provide with other information like interests inferred from web page views, or data lawfully obtained from data brokers, such as past purchase or location data, or publicly available data, (3) contact me or enable others to contact me by email or other means with offers for different types of goods and services, and (4) retain my information while I am engaging with marketing messages that I receive and for a reasonable amount of time thereafter. I understand I can opt out at any time through an email that I receive, or by clicking here

Around the world, rainforests play a critically important role in climate regulation.

Trees and plants absorb and store a massive amount of carbon dioxide from the air, and in return, through photosynthesis, produce oxygen upon which all life on earth depends.

Rainforests also regularly release carbon dioxide through processes like respiration, decay and fires, but they have always absorbed more carbon dioxide than they release, acting as “carbon sinks,” according to experts.

In 2021, NASA’s Jet Propulsion Laboratory revealed that between 2000 and 2019, the ability of tropical rainforests to absorb large amounts of carbon decreased due to “large-scale deforestation, habitat degradation, and climate change effects, like more frequent droughts and fires.”

Now, at least one region’s rainforests have reached a tipping point.

Australia’s rainforests are the first in the world to switch from being a net carbon sink to a net carbon source, according to a news release from Australian National University and a study published Oct. 15 in Nature.

The study analyzed data from 1971 to 2019 and determined that more trees are dying from climate-related changes such as extreme temperatures, dryness and drought. In additional to increased tree mortality, this loss is not being offset by new tree growth, according to lead author Dr. Hannah Carle.

“Forests help to curb the worst effects of climate change by absorbing some of the carbon dioxide released from burning fossil fuels,” Carle said in the release. “We rely on them more than most people realize.”

Experts say this new finding has impacts on emission reduction targets, which are based, in part, on forests’ capacity to absorb carbon.

“Current models may overestimate the capacity of tropical forests to help offset fossil fuel emissions,” Carle said.

The study also found that an increase in the number and severity of cyclones driven by climate change is making it harder for new trees to grow, exacerbating the problem.

Per capita, Australia is one of the world’s biggest polluters and is already facing the consequences of a warming climate, the BBC reported.

The research team included Hannah Carle, David Bauman, Michael N. Evans, Ingrid Coughlin, Oliver Binks, Andrew Ford, Matthew Bradford, Adrienne Nicotra, Helen Murphy and Patrick Meir.

_____