Impact of Climate on the Global Capacity for Enhanced Rock Weathering on Croplands
Geoengineering News
Impact of Climate on the Global Capacity for Enhanced Rock Weathering on Croplands
Enhanced rock weathering (ERW) on croplands has emerged as an economically and ecologically promising negative emissions technology. However, estimated total carbon sequestration potential from ERW on croplands and its potential sensitivity to climate conditions requires further understanding. Here we combine 1-D reactive transport modeling with climate model experiments to simulate ERW on ∼1,000 agricultural sites globally. Applying a fixed rate of 10 tons of basalt dust per hectare on these sites sequesters 64 gigatons of CO2 over a 75-year period; when extrapolated to all agricultural land, ERW sequesters 217 gigatons of CO2 over the same time interval. However, we find that a significant fraction of applied basalt does not weather even on a multidecadal timescale, indicating the need to optimize application strategies for cost effectiveness. We find that ERW becomes modestly more effective with global warming and predict that the payback period for a given ERW deployment is significantly shorter in hot and humid environments currently coinciding with relatively low per-capita incomes. These results provide strong impetus for investment in agricultural reform in developing economies and highlight an additional potential co-benefit of ERW.
Key Points
Enhanced rock weathering (ERW) with fixed annual application rates of 10 tons of basalt dust per hectare on 1,000 global cropland sites sequesters 64 gigatons of CO2 over 2006–2080
Extrapolated to all croplands, ERW with a fixed application rate of 10 tons of basalt dust per hectare sequesters 215 gigatons of CO2 over 2006–2080
ERW is resilient to global climate change but is much more efficient over hot and humid environments
Plain Language Summary
Enhanced rock weathering (ERW) on croplands is a promising negative emissions concept that accelerates natural weathering by amending soils with crushed rock. Our simulations of ERW with a fixed rate of 10 tons of basalt dust per hectare on all global croplands suggest ERW can sequester >200 gigatons of CO2 over a 75-year period. This suggests that cost and logistical concerns, rather than weathering potential, are likely to be the key limiting factors for large-scale deployment of enhanced weathering. Notably, ERW is resilient to global climate change and becomes more effective with global warming. ERW is moreover far more efficient in hot and humid environments currently coinciding with relatively low per-capita gross domestic product economies. Our study provides strong support for the assertion that ERW represents a resilient carbon capture strategy that is non-competitive for arable land and can foster CO2 removal at the gigaton scale.
Source: AGU
Peter Eisenberger
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Jim Baird
The climate threat is excess heat.
Ninety-three percent of this threat is going into the oceans mostly into to the top 5 meters of the tropics.
This heat is thermally stratifying the oceans and is also a source of energy like any other that can be converted to work.
This stratification lends itself to the conversion of the surface heat into work at a conversion efficiency of 7.6% and with heat pipes the balance can be sent to a depth of 1000 where is no longer any kind of environmental threat. At least until it diffuses back to the surface which it will do in 226 years at which time it too can be converted to work at an efficiency of 7.6% and the balance sent again into the deep.
Through 13 cycles - ~2938 years - all of the heat of warming will have been converted to work and the waste of those conversions will have been harmlessly dissipated into space because the green house blanket will also have been dissipated.
This is the kind of ships that are required to solve this problem while producing twice as much energy as is currently being derived from fossil fuels.
Some ideas simply aren’t able to escape the confines of conventional “wisdom”? Because we are trying to solve the problem with the same sort of thinking that created it.
Regards.
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Michael Hayes
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Michael Hayes
Jim Baird
You can use energy that mitigates every consequence of global warming (see below) you like.
But it seems to me it is redundant to try to build up sea ice when you have already short circuited the movement of tropical heat to the poles?
From: carbondiox...@googlegroups.com On Behalf Of Michael Hayes
Sent: August 18, 2023 8:21 AM
To: Jim Baird <jim....@gwmitigation.com>
Cc: Peter Eisenberger <peter.ei...@gmail.com>; Carbon Dioxide Removal <CarbonDiox...@googlegroups.com>
Subject: Re: [CDR] Impact of Climate on the Global Capacity for Enhanced Rock Weathering on Croplands
A revision and extension of the prior post:
The one exception to the list of CDR/SRM methods that can have unintended consequences, or over use potential, or FF involvement may be simply building sea ice of different types.
During the creation of ice, we see CO2/CH4 dragged to the bottom by super cooled brine and converted to hydrates, thus CDR is achieved. On the surface of the ice, we can create Ice Fog, a 10 to 30 micron size ice crystal that can create an ice 'fog' that has a long hang time in the air, thus it can travel on the wind for wide area coverage at no cost, to give the ice surface a highly reflective protective top crust. The energy needs can use many methods including TG.
With a robust ability to generate different forms of ice, creating and maintaining lage ice fields in non polar oceanic gyres, oceanic deserts, may become possible.
Coupling SRM/CDR via ice engineering should gain wide policy/public support as it does something easily understood and progress can be watched via satellite coverage. The engineering should be rather simple so as to support massive deployment, and getting paid to do the above could use a few good ideas.
Best regards
On Fri, Aug 18, 2023, 8:02 AM Michael Hayes <electro...@gmail.com> wrote:
Jim, Peter, et al.,
The one exception to the list of CDR/SRM methods that can have unintended consequences, or over use potential, or FF involvement may be simply building polar ice of different types.
During the creation of ice, we see CO2/CH4 dragged to the bottom by super cooled brine and converted to hydrates, thus CDR is achieved. On the surface of the ice, we can create Ice Fog, a 10 to 30 micro ice crystal 'fog' that has a long hang time in the air, thus it can travel on the wind for wide area coverage at no cost, to give the ice surface a highly reflective protectivr top crust. The energy needs can use many methods including TG.
Coupling SRM/CDR via ice engineering should gain wide policy/public support as it does something easily understood and progress can be watched via satellite coverage. The engineering should be rather simple so as to support massive deployment, and getting paid to do the above could use a few good ideas.
Best regards
On Fri, Aug 18, 2023, 7:01 AM Jim Baird <jim....@gwmitigation.com> wrote:
The climate threat is excess heat.
Ninety-three percent of this threat is going into the oceans mostly into to the top 5 meters of the tropics.
This heat is thermally stratifying the oceans and is also a source of energy like any other that can be converted to work.
This stratification lends itself to the conversion of the surface heat into work at a conversion efficiency of 7.6% and with heat pipes the balance can be sent to a depth of 1000 where is no longer any kind of environmental threat. At least until it diffuses back to the surface which it will do in 226 years at which time it too can be converted to work at an efficiency of 7.6% and the balance sent again into the deep.
Through 13 cycles - ~2938 years - all of the heat of warming will have been converted to work and the waste of those conversions will have been harmlessly dissipated into space because the green house blanket will also have been dissipated.
This is the kind of ships that are required to solve this problem while producing twice as much energy as is currently being derived from fossil fuels.
Some ideas simply aren’t able to escape the confines of conventional “wisdom”? Because we are trying to solve the problem with the same sort of thinking that created it.
To view this discussion on the web visit https://groups.google.com/d/msgid/CarbonDioxideRemoval/CABjtO1cUbCTzpQR0Ci9F8m20W4jvfMi69pvgyZwn_O6UEPjuRA%40mail.gmail.com.
