New Study: Forests in Australia Emitting More Carbon Than They Absorb

Forests on the other side of climate change 

Who would have thought that resilient ecosystems, stable for millions of years, could be fundamentally transformed in a single generation? New research on forests in Australia reveals this is no longer a theory, but our new reality for some Australians.

A study, analysing 49 years of data from 20 forests in Queensland has uncovered a shift: for the past 25 years, these forests have been emitting more carbon than they absorb. Trees and plants store carbon as they grow and release it when they die and decay. Today, trees are dying faster than new ones can grow to replace them, turning these systems from carbon sinks to carbon emitters.  

Why is this happening?  

The culprit is no other than climate change. These forests, mainly rainforests, are built for stable hot and wet conditions. However, as the climate changes, these forests have become more exposed to droughts and extreme temperatures, doubling the rate at which trees are dying and reducing the rate of growth. Additionally, more frequent and powerful cyclones are causing widespread physical damage, pushing these fragile ecosystems past their tipping point.  

What does this mean?  

This discovery challenges a key assumption we have held about forests’ roles in fighting against global warming: that we could safely rely on them as a natural and powerful tool to absorb huge amounts of our carbon emissions. Currently, they are estimated to absorb a massive 16 billion metric tonnes of carbon dioxide from the atmosphere annually. To put that in perspective, this natural absorption offsets nearly 40% of the 41.42 billion tonnes of anthropogenic CO₂ emissions each year. Over centuries, forests have stored away 861 gigatonnes of carbon within their living biomass and the soil beneath them. 

The role of tropical forests, in particular, deserve a spotlight. Research suggests they single-handedly prevent over 1^oC of global warming. The majority of this, about 75%, is due to their ability to sequester carbon. The remaining 25% is achieved through their physical cooling: shading, water evaporation forming clouds, and disrupting air flows.  

This study shows we can no longer take that assumption for granted and that their role in combating climate change may have been overestimated.

What does this tell us? 

In other words, as seen in the recent article exploring methane leaks beneath Antarctica, our understanding of the long-term impact of climate change is significantly limited. And unlike distant polar ice sheets, we all have forests in our backyards acting as guardians of our environment. The Queensland study may not currently be a universal blueprint, but it does serve as a warning. If we continue to push global forests past their tipping points, we will inevitably create dangerous feedback loops that intensify global warming. Considering that these feedback loops have not been considered in climate projections means we face greater danger than we previously imagined. 

Forests have so far been acting like a dam absorbing some of our emissions, the floodgates are now opening under the pressure. This new reality reinforces an urgency: we must cut anthropogenic emissions at their source while simultaneously drastically ramping up our efforts to protect existing forests and restore new ones. 

This is a call to action for leaders around the world. We need stronger policies that enforce strict decarbonisation efforts and the tools to accelerate the transition to a green economy. 

The private sector holds immense responsibility and power. Industry representatives must push for climate solutions within their sectors, providing members with the knowledge and guidance to make this transition possible. At CAFA, we are inspired by the momentum created by our members, and we urge all other industries to join the global movement for climate action.  

One could feel disheartened by this news, but we must remember an important fact: every fraction of a degree of warming we prevent makes a world of difference. Staying below the 2°𝐶 limit is not an all-or-nothing game. Every step we take reduces the severity of the climate catastrophe and safeguards our collective future.