It’s fun how things derided for so long turn around to become true in the fullness of time. One of which has been – and for the life of me, the Alzheimer’s is catching up, I cannot now remember the name of the famed scientists who made this point (I keep wanting to say Buckminster Fuller but it’s not him and I have spent decades confusing the two names) – that carbon retention in the soil is an obvious and sensible manner of beating climate change. But, importantly, it’s not in forests, rather it’s in pastures.
Which is what this latest research is now telling us:
The study, published in the journal Nature, analysed more than 100 experiments from across the world in which soils, plants and trees were exposed to higher CO2 levels than in today’s atmosphere. The biomass growing in forests rose by 23% in experiments where the CO2 level used was double pre-industrial atmospheric levels. It is 50% higher today. But the forest soils did not store any more organic carbon at all.
It was thought that biomass and soil carbon would increase in tandem, as more plant biomass falls to the ground and turns into organic matter. But increased plant and tree growth requires more nutrients from the soil, which may explain the new finding, the scientists said. Extracting the extra nutrients requires the plants to increase the symbiotic microbial activity in their roots, which then releases CO2 to the atmosphere that might otherwise have remained locked in the soil.
So, from forests, we gain a bolus of carbon sequestration but not an ever increasing amount of it. However, soils under pasture?
The researchers found that in grasslands, elevated CO2 led to 9% plant growth – less than forests – but soil carbon rose by 8%.
That continues over time. As, logically, we would expect as under pasture soils continue to get thicker and thicker in a manner that they don’t in forests.
So, want to beat climate change? Have lots of pastures. How do we have lots of pastures? We raise animals on them. Which means we all go eat meat to beat climate change.
Which is nice, isn’t it?