" it must be remembered that the decomposition process of minerals on
land is extremely slow compared to ocean seeding with a microscopic
sized particle" - at 100um in most cases completely weathered in < 10 years.
" If we want to be serious about the problem of climate change then it
would have to be a rapid reaction" - clearly you don't want it to take
centuries! But nor do you want to emit of a lot of CO2 upfront grinding
it very fine to get a quicker sequestration (also MUCH more expensive).
100um / under 10y for total weathering seems like a reasonable balance.
If you have extra money to spend, better just spread more olivine.
"the decomposition process of minerals on land is extremely slow
compared to ocean seeding with a microscopic sized particle" - a
microscopic, eg 1um particle will always weather much faster whether on
land or in sea, but the cost is far larger both financially and in CO2
emissions to make it.
"As for the lifeforms in the oceans don't they build calcium carbonate
shells and in doing so absorb the carbon dioxide that way?" - actually
their raw material is for shell building bicarbonate and the process of
removing carbonate from it releases CO2 and increases ocean acidity. But
of course in the long term you are right - CO2 from the atmos ends up as
carbonate rock. In order to support this process alkalinity needs to be
constantly added to the oceans - and this is done naturally by the
terrestrial weathering of magnesium silicate rock.
Oliver.
On 22/01/2013 18:18, Kevin Coleman wrote:
> Than you Oliver,
> A most interesting assessment. I wasn't aware that the original
> suggestion back sometime last year was for a land application. From
> what I can recall it was most definitely suggested that it would be
> applied to the oceans....somewhere.
> Anyway its a bit of a moot point as the obvious downside is the
> extraction/recovery of olivine whether as a raw mineral or as a mining
> waste by product. Either way it will have to be collected and ground
> up. Even if it is applied to the land it must be remembered that the
> decomposition process of minerals on land is extremely slow compared
> to ocean seeding with a microscopic sized particle. I recall an
> experiment from 6th form where we measured the times for certain solid
> minerals to completely react with a chemical solution. The idea was to
> demonstrate just how reactions could be controlled by the size of the
> solid minerals used. This is exactly the same idea. If we want to be
> serious about the problem of climate change then it would have to be a
> rapid reaction. Otherwise it would simply fall behind the rate of co2
> production (and the other carbon compounds causing climatic changes)
> and we would be getting nowhere fast.
>
> As for the lifeforms in the oceans don't they build calcium carbonate
> shells and in doing so absorb the carbon dioxide that way? If so
> surely the increased acidity of the oceans as they stand now would
> first need to be neutralised which would take a load of olivine or
> similar mineral to accomplish this. Only then would the lifeforms
> proliferate and take down the carbon compounds. Its the acidity that
> dissolves the shells.
> Kev C
> On 22/01/2013 14:05, Oliver Tickell wrote:
>> Note that the article applies to the addition of very fine (1um)
>> olivine powder direct to oceans. This requires a huger energy input,
>> 10^4 times greater than that of creating the 100um granules suitable
>> for spreading to land (grinding energy ~ surface area).
>>
>> Yes, the volume of olivine required is large - but then so is the
>> problem. By rule of thumb, you need the same weight of olivine as of
>> the CO2 you want to sequester. So 1Gt of olivine for 1Gt of CO2
>> sequestered. And yes, it has to come from somewhere. Fortunately it
>> is abundant and there are already huge volumes of it at existing and
>> former mines as dumped overburden. For example, at nickel mines, and
>> diamond mines. Maybe even at coal mines! Digging it up and moving it
>> about will still have an impact, but a much smaller one than allowing
>> global warming to let rip.
>>
>> BTW the preferential fertilisation of diatoms would not be an
>> altogether bad thing. They are good at sequestering carbon to ocean
>> depths in their own right. Also they are good at feeding ocean food
>> chains leading to fish. But obviously impacts would need to be
>> closely monitored - on top of everything else we are doing to oceans,
>> like wiping out top level predators, over-fishing, filling up with
>> waste plastic, etc. Also you need to consider the benefits of
>> restoring alkalinity to the oceans which olivine application would do
>> (whether applied to land or sea, the bicarbonate and silicic acid
>> would tend to end up the oceans).
>>
>> Oliver.
>>
>> On 22/01/2013 07:06, Kevin Coleman wrote:
>>> To All,
>>> The article linked to below answers a few of my questions from
>>> last year regarding the efficiency of Olivine as a geoengineered
>>> solution to carbon emissions.
>>>
>>> As I said at the time the apparent benefits had hidden costs in
>>> terms of energy required to extract, transport, process and deliver
>>> to the ocean. The issue of global quantities required to absorb the
>>> carbon compared to what is globally available which I also asked to
>>> be clarified with no response has been only partially answered in
>>> this particular piece.
>>>
>>> In this respect they do say that the amount required to facilitate
>>> the absorption of about 9% carbon dioxide is substantial (3 billion
>>> tonnes) and would require an industry equivalent to the current coal
>>> mining industry and therefore equally destructive to ecosystems. You
>>> cannot dig a hole without digging up some natural habitat be it a
>>> lush rainforest or a desert. Each has its role and function in the
>>> greater scheme of things. Neither is in plentiful supply.
>>>
>>> When I challenged the idea last year no-one from the AMEG cartel,
>>> who were promoting geoengineering the planet, was willing to come
>>> forward with the necessary details to answer my legitimate questions.
>>>
>>> It was only when I received an article from a friend in the US that
>>> some of those questions were answered. The article relates to some
>>> serious research into Olivine as a solution to carbon capture in the
>>> oceans. Despite previous claims it appears to be yet another dead end.
>>>
>>> But what I also find interesting is the last two paragraphs
>>> references to two other solutions. They too are now being also
>>> deemed equally doubtful. One of them being cloud seeding.
>>>
>>> Kev C
>>> http://www.terradaily.com/m/reports/Climate_Rock_fix_for_oceans_is_badly_flawed_study_999.html
>>>
>>>
>>
>
|