25 percent more photosynthesis happening on Earth – nature cycles 30-55 Gt extra carbon per year

Photosynthesis in nature happens 25% fasterNature, it seems, is breathing faster than we thought. El Niños may have something to do with that.

Thanks to Jan Ingenhousz we’ve known since 1778 that water, air and light come together in photosynthesis. Now finally we’ve come close to quantifying the lung capacity of all of Earth’s plant life – inhaling CO2, and exhaling the oxygen we depend on.

Previous estimates were based on extrapolation of laboratory experiments. These have led to an underestimation, says a team of researchers from American, Dutch, Australian and Japanese universities.

Today they have published their own findings in Nature. These are not derived from the lab, but from oxygen isotope measurements outside, in the real world – for which they travelled to every tip.

More photosynthesis = more of everything

There could be 25 percent more photosynthesis going on than we thought. This would imply we have to reconsider the other biochemical processes that contribute to Earth’s carbon cycle as well. You can’t simply discover a higher oxygen production, without apparently having higher oxygen binding as well. The same goes for CO2. If nature grows faster than we thought, it must be dying faster too – biomass rotting processes must also be happening faster than we thought.

This is quite shaking news to many Earth and Life Sciences – also for climatologists. Plant life cycles not 120 gigatonnes of carbon each year, but 150-175, the Nature publication states.

From ENSO back to climate

Somehow we’ve overlooked the importance of the ENSO cycle to biology, the research indicates. During El Niños and La Niñas locally precipitation increases, widening a bottleneck for photosynthesis.

Of course elsewhere droughts have the opposite effect. If this research shows the importance of rainfall to the carbon cycle – it also stresses the importance of a possible expansion of arid zones and the development of new seasonal dry periods. Besides, don’t take plant life for granted anyway.

© Rolf Schuttenhelm | www.bitsofscience.org

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