Australia’s Tropical Rainforests Shift from Carbon Sink to Source

Australia’s rainforests, once powerful absorbers of carbon dioxide, are now releasing more carbon than they capture. The research from The Guardian tracked over 11,00 trees across more than 20 forest sites in Queensland from roughly about more than 50 years. It found that rising temperatures, frequent droughts, and increased tree deaths have caused the forests to shift from storing carbon to emitting it. This discovery raises major concerns about Australia’s ability to meet its net-zero goals by 2050.

The study focused on the carbon stored above the ground in tree trunks and branches, excluding roots and soil carbon. Scientists explained that the change from being a carbon sink to a carbon source was largely due to higher rates of tree mortality linked to climate change. These deaths are connected to rising temperatures and increasingly extreme weather conditions that weaken forest ecosystems. Researchers from James Cook University and the Australian National University emphasized that this marks the first recorded instance of a tropical rainforest system shifting in this way, signaling a serious warning for other ecosystems facing similar stress.

Researchers from the involved institutions are now working to better understand how forest ecosystems can adapt to a warming climate. At James Cook University, scientists are continuing long-term ecological monitoring to study how tree species respond to rising temperatures and changing rainfall patterns. The Australian National University’s Forest Carbon Monitoring Program is developing improved tools for measuring and predicting carbon storage in forest environments, allowing researchers to identify areas most at risk of losing their carbon-absorbing capacity. Meanwhile, the CSIRO’s work on forest and landscape resilience aims to apply this data to real-world conservation and management efforts. Together, these projects show that Australian scientists are not only documenting the effects of climate change but also working toward solutions to restore and protect the nation’s carbon-rich rainforests.

This transformation of the rainforests represents more than just an ecological concern; it also poses an economic and environmental challenge for Australia’s national climate strategy. As forests lose their ability to absorb carbon, the burden of reducing emissions shifts further toward the industrial and energy sectors. Scientists warn that without stronger conservation measures and restoration programs, Australia’s long-term goal of reaching net-zero emissions by 2050 will become even harder to achieve.

Citations:

• James Cook University, Centre for Tropical Ecology Reports (2025)

• Australian National University, Forest Carbon Monitoring Program (2024)

• The Guardian (2025) “Australian tropical rainforest trees switch in world first from carbon sink to emissions source.”

• CSIRO Climate Research (2025)