Sunday, September 16, 2018

Farms Can Grow More and Slow Climate Change

New ways of digging the dirt could both deliver more food and slow climate change.  And farmers in the developing world are making a difference.

Avoiding bare fields can increase soil carbon storage. (Image Credit: Whatlep, via Wikimedia Commons) Click to Enlarge.
Two new studies have confirmed that farmers can win both ways, achieving a boost in harvests and helping to slow climate change.

One says that they can successfully farm with techniques that can help slow global warming and add to the store of carbon sequestered in the soils around the globe.

And a second study confirms that a range of tested and sustainable practices is already stepping up yields in small farms worldwide, while dramatically reducing greenhouse gas emissions, soil erosion and pesticide use.

Both studies address a planetary dilemma.  Global agriculture is at serious risk from global warming and climate change driven by profligate fossil fuel combustion.  But global agriculture – powered by greenhouse gas-emitting fossil fuels, ploughing, pesticides, and herbicides – is also helping to drive global warming and climate change.

Massive changes needed
And while researchers have persistently argued that it should be possible both to feed the 9bn people expected by 2050, and to contain global warming to no more than 2°C by 2100, such advances can be achieved only by massive changes in diet and expectations.  But both new studies focus on what is both practicable and possible right now.

US researchers report in the journal Science Advances that they have identified a range of well-established farming practices that – if adopted by everybody – could capture enough carbon from the atmosphere and store it in the world’s soils at a rate that could make a significant difference.

They suggest that simple approaches – cover crops, more thoughtful use of grazing animals, the planting of legumes on rangelands and so on – could, if coupled with dramatic reductions in carbon dioxide emissions, notionally add as much as 1.78 billion tonnes of carbon from the atmosphere to soils, lowering temperatures by 0.26°C. Since 1880, global average temperatures have already risen by about 1°C.

More tentatively, they suggest that if farmers added biochar – the residue of crops burned to make charcoal – to their soils, this could reduce global warming by as much as 0.46°C.

Massive shifts to renewable energy worldwide would also be necessary:  ever more carbon dioxide in the atmosphere would make changes in farming practices proportionately ever less effective.  The bonus is that more carbon drawn down from the atmosphere and stored in the soil would pay off with healthier soils and better crop conditions.

Read more at Farms Can Grow More and Slow Climate Change

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