Can ‘enhanced rock weathering’ help combat climate change?

[Paul_F]

Still snake oil. How do you think this rock is around for so many millions of years because it weathers extremly slooooooooooooooooooowly.

The whole way it's place in the carbon cycle works is that it doesn't weather when underground and not exposed to the atmosphere.

But very little of it is fresh what there doing is dumping quarry waste probably crushed 50 years ago on agricultural land for some mythical benefit and charging a fortune to a load of idiots who believe in this greenwash nonsense.

Even quarry waste from 50 years ago probably isn't that weathered: won't be that finely crushed and anything buried in a big pile isn't going to weather fast. It's pretty easy to validate if it's working or not: take samples of the soil before and after and measure the ratio of carbonates to silicates.

[Mart]

Absolute snake oil. Quarry waste that nobody wants suddenly has a value to gullable people. You might get a slight benefit from improved drainage but even that is stretching it with the minute quantities applied. No the real quarries use this waste to produce added value products like blocks and beams.

Only works for certain rock types, i.e. igneous ones which will react chemically with atmospheric carbon dioxide to form carbonates. As such, it's probably the most fundamental part of the earth's carbon cycle (at least on long timeframes) - https://en.wikipedia.org/wiki/Carbonate–silicate_cycle
The logistics of shifting the megatonnes of the stuff around the world to the right places (presumably added to fertilizer mixes?) aren't even that hard, but right now the financial justification doesn't exist. Either we need to pay farmers for CO₂ removal (hard to justify without carbon taxes) or we need to demonstrate that the performance of the fertilizer is somehow improved.

Or we need to admit that actually we got it wrong in that CO2 is not a climate problem at all at its present levels but could become a very serious problem if allowed to go much lower. Even at current levels plants are struggling to survive which is why farmers with glasshouses increase the level of CO2 as the plants respond with higher yields.

I think that's dangerously close to the AGW denial argument that 'CO2 is plant food'. No end of studies showing that higher CO2 levels do lead to larger plants, but with lower nutritional value. In fact rising CO2 levels are a massive concern for rice nutrition, and the vast numbers dependant on it.

The greenhouse co-located argument is also a myth, since whilst higher CO2 levels can be beneficial, that goes hand in hand with controlled temps, fertilizer, and watering, so doesn't reflect the vast majority of plant growth.

With regard to the rock wethaering CCS method, this isn't new news, and looks to be the most promising, though like all of them, vastly huge and expensive, but the only way to prevent rising temps catching up with higher CO2(e) levels, as there's a lag of several decades. Without CCS in the second half of this century, there is no hope of keeping the temp rise below +2C, let alone the now doubtful +1.5C.

As to the rocks not already having been weathered away, I think that's simply down to size/surface area. All of the articles on this method are clear that the rock needs to be crushed to dust, thus increasing its surface area by a simply vast amount, and thereby accelerating the weathering process.

[Marcus]

CO2 definitely needs to be reduced.

I think this idea is fine on a small local scale like this, but i would be wary of scaling it up. A bit like the original biomass idea: burning waste sawdust and shavings locally instead of coal was fine, but shredding primeval forest wholesale to feed powerstations is plain stupid

[renewablejohn]

Only works for certain rock types, i.e. igneous ones which will react chemically with atmospheric carbon dioxide to form carbonates. As such, it's probably the most fundamental part of the earth's carbon cycle (at least on long timeframes) - https://en.wikipedia.org/wiki/Carbonate–silicate_cycle
The logistics of shifting the megatonnes of the stuff around the world to the right places (presumably added to fertilizer mixes?) aren't even that hard, but right now the financial justification doesn't exist. Either we need to pay farmers for CO₂ removal (hard to justify without carbon taxes) or we need to demonstrate that the performance of the fertilizer is somehow improved.

Or we need to admit that actually we got it wrong in that CO2 is not a climate problem at all at its present levels but could become a very serious problem if allowed to go much lower. Even at current levels plants are struggling to survive which is why farmers with glasshouses increase the level of CO2 as the plants respond with higher yields.

I think that's dangerously close to the AGW denial argument that 'CO2 is plant food'. No end of studies showing that higher CO2 levels do lead to larger plants, but with lower nutritional value. In fact rising CO2 levels are a massive concern for rice nutrition, and the vast numbers dependant on it.

The greenhouse co-located argument is also a myth, since whilst higher CO2 levels can be beneficial, that goes hand in hand with controlled temps, fertilizer, and watering, so doesn't reflect the vast majority of plant growth.

With regard to the rock wethaering CCS method, this isn't new news, and looks to be the most promising, though like all of them, vastly huge and expensive, but the only way to prevent rising temps catching up with higher CO2(e) levels, as there's a lag of several decades. Without CCS in the second half of this century, there is no hope of keeping the temp rise below +2C, let alone the now doubtful +1.5C.

As to the rocks not already having been weathered away, I think that's simply down to size/surface area. All of the articles on this method are clear that the rock needs to be crushed to dust, thus increasing its surface area by a simply vast amount, and thereby accelerating the weathering process.

Its not denial its stating the obvious. Nail the real culprit by stopping high altitude flights pumping vapour trails everywhere but no cannot upset the droves of hypocrites wanting holidays abroad and cling to the bogeyman of CO2 despite the fact that we all know levels have been far higher through earths history and if it gets to low life on earth will cease.

[Mart]

I'm going to buy one of these, just to not touch that post with it.

[renewablejohn]

I'm going to buy one of these, just to not touch that post with it.

So what did the evidence of covid prove when the skys were clear of planes or do you bury your head in the sand with your barge pole stuck in the air and just deny it never happened.

https://www.sciencedaily.com/releases/2 ... 130311.htm