This could be our tipping point

NZ scientists taking part in climate change research find we’re getting close to a dangerous tipping point.

When NZ biogeochemistry professor Louis Schipper first saw the data on carbon emissions for his study, the words that ran through his head were too explicit to print. His team from the University of Waikato and Northern Arizona University have found Earth’s ability to absorb carbon emissions through plants will likely cross a significant tipping point within just two decades at the current rate of warming.

The study used 20+ years of data from every major type of ecosystem (biomes) on the planet, including a site at Paeroa.

Much stronger efforts will be needed to slow climate change.

The results show that the amount of carbon that plants can absorb – known as a land carbon sink – could reach a critical tipping point within the next 20‒30 years. Once past it, plant biomes will release more carbon globally than they lock away, accelerating climate change.

Plants pull in CO₂ through photosynthesis, then release it back into the atmosphere via respiration. In the past few decades, landbased ecosystems have generally taken in more carbon than they have released, absorbing nearly a third of carbon emissions created by humans.

The study suggests much stronger efforts will be needed to slow climate impacts.

“We have been relying on ecosystems to provide a service to us – to offset fossil fuel CO2 emissions,” says Professor Schipper. “We should stop relying on that.

“We have to do at least two things: we have to plant trees to fix carbon, and we have to fundamentally change how we behave to reduce our emissions.”

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