3 ms·

One of the surprising facts in the article is this: >Global fire activity was lowest on record. The author explain why this is true a few sentences later- the

One of the surprising facts in the article is this: >Global fire activity was lowest on record. The author explain why this is true a few sentences later- the change is being >driven primarily by the conversion of frequently burning savannas to agricultural areas. I wonder if this is one of those "humans accidentally geoengineering a few more years of habitability into the planet" things, like the global chilling effect that our pollutants have when they're highly reflective of light. Only, in this case, by preventing fires we're keeping more carbon locked into plants. (This is obviously a gross simplification, but this could be a possibility, right?)

throwaway5752 7y ago
Holy crap, no. They are tilling over carbon sinks (grasslands) and ruining them. I don't know that we know enough about soil biota (and the impact of the various agricultural products that typically come along with this conversion) to know how long, assuming it is even possible, to reestablish them. It's horrible news.
hwillis 7y ago
> Only, in this case, by preventing fires we're keeping more carbon locked into plants. Completely backwards. For example see slash-and-burn farming[1], where fields are intentionally burnt to return carbon to the soil. Plants, on their own, are not great at carbon capture. They grow and die and the carbon they captured gets re-released. To be a truly effective carbon sink you should ideally be converting plant matter into a stable form, like peat- peat takes centuries to form, but locks carbon into the ground. Rainforests also create very carbon-rich sediments. Grasslands aren't the greatest, but when they burn they don't convert 100% into CO2 and lots of carbon is left in the soil. Farmlands on the other hand are scrupulous about harvesting all their plants and growing plants that don't leave behind much. They grow plants that are mostly fruiting body, and then the parts humans don't eat are fed to livestock, and it all gets turned with very high efficiency into CO2 and methane, which is an even more powerful greenhouse gas (until if eventually breaks down into CO2). [1]: https://en.wikipedia.org/wiki/Slash-and-burn https://en.wikipedia.org/wiki/Slash-and-burn

throwaway5752 7y ago

Holy crap, no. They are tilling over carbon sinks (grasslands) and ruining them. I don't know that we know enough about soil biota (and the impact of the various agricultural products that typically come along with this conversion) to know how long, assuming it is even possible, to reestablish them. It's horrible news.

hwillis 7y ago

> Only, in this case, by preventing fires we're keeping more carbon locked into plants. Completely backwards. For example see slash-and-burn farming[1], where fields are intentionally burnt to return carbon to the soil. Plants, on their own, are not great at carbon capture. They grow and die and the carbon they captured gets re-released. To be a truly effective carbon sink you should ideally be converting plant matter into a stable form, like peat- peat takes centuries to form, but locks carbon into the ground. Rainforests also create very carbon-rich sediments. Grasslands aren't the greatest, but when they burn they don't convert 100% into CO2 and lots of carbon is left in the soil. Farmlands on the other hand are scrupulous about harvesting all their plants and growing plants that don't leave behind much. They grow plants that are mostly fruiting body, and then the parts humans don't eat are fed to livestock, and it all gets turned with very high efficiency into CO2 and methane, which is an even more powerful greenhouse gas (until if eventually breaks down into CO2). [1]: https://en.wikipedia.org/wiki/Slash-and-burn https://en.wikipedia.org/wiki/Slash-and-burn