Phillip, list, Leo
Thanks.
I just skimmed through your ocean-oriented biomass paper
http://rsta.royalsocietypublishing.org/content/370/1974/4317#T2
<http://rsta.royalsocietypublishing.org/content/370/1974/4317#T2>, and was
surprised/delighted to see biochar, but not BECCS. So I sense we are not very
far apart on the question of appropriately analyzing the CDR benefits of
biochar.
See inserts.
> On May 3, 2016, at 3:15 PM, Phillip Williamson (ENV) <[email protected]>
> wrote:
>
> Ron -
>
> Yes, the longterm effect of biochar on crop productivity is an important
> consideration.
[RWL: Agreed. I see I didn’t make a good enough case for the coupling
of increased productivity with increased sequestration. As one example,
suppose that biochar uses dedicated forests, with (assumed) doubled
productivity which means that (during all the subsequent growth period) CO2 is
coming out of the atmosphere twice as face as without biochar. Maybe not
permanent sequestration, but anything out of the atmosphere for any time period
is valuable. With emphasis on continuing (s opposed to one-time) biochar, that
removal is close to “ permanent”.
More important - the biochar will be leading to increased microbe and
fungal populations in the soil; that is not NPP, but is supportive of NPP.
>
> But NPP can’t be directly equated with carbon sequestration: most will be
> re-cycled.
[RWL: I agree. All the added soil carbon will be recycled on some
time scale - but the portion that is subsequently (and sooner) turned into
biochar will have had a large impact on atmospheric carbon (after its placement
in soil - contradicting the “approximately half” statement that I quoted from
2010 below).
> What matters is whether soil carbon will be significantly increased, in
> addition to what’s added via biochar - with a reasonable likelihood of
> stability, under future climate warming (there will be some).
[RWL: Agreed - but I would say “how much” rather than “whether”
increase. Much of the biochar now being used is going to the world’s worst
soils - that is where the best economics lie. No economic benefits today (in
the absence of carbon credits) unless one is increasing both soil and
above-ground carbon. Re “stability” - certainly some portion of all biochar is
labile - but the majority has plenty of lifetime to be considered seriously.
> Information on such aspects is currently uncertain.
[RWL: Agreed; this is one very difficult analysis problem. The sad
part of this story is that the past (maybe not continuing ?) emphasis on (the
much-troubled) BECCS has kept biochar’s information-gathering much lower than
is deserved. I repeat this is likely mostly caused by many analysts’
inappropriately stopping the CDR analysis at the date of biochar’s placement -
not after some (arbitrary) time like a century or two.
Again - thanks for (I sense) mostly agreeing that most present
comparisons of biochar and BECCS have not understood how much extra
sequestration can be (not necessarily will be) obtained after biochar
placement. Your work on ocean biomass (and “blue” biochar) can have a very
valuable impact that too few (both land and ocean) biomass experts are
understanding. Placement of harvested ocean algae as biochar on land is not
being studied enough, given the present rapid growth of a biochar industry (and
the much slower growth of the BECCS industry).
Ron
>
> Phil Williamson
> From: [email protected]
> <mailto:[email protected]> <[email protected]
> <mailto:[email protected]>> on behalf of Ronal W.Larson
> <[email protected] <mailto:[email protected]>>
> Sent: 03 May 2016 21:49
> To: Geoengineering
> Cc: Leo Hickman
> Subject: Re: [geo] Analysis: How much is the UK relying on 'negative
> emissions' to meet its climate targets?
>
> List cc Leo Hickman
>
> 1. This is to comment on the 15 April sixth report at the Carbon Brief site
> on NETs (mostly on BECCS) as provided to this list last Saturday.
> http://www.carbonbrief.org/analysis-how-much-is-the-uk-relying-on-negative-emissions-to-meet-its-climate-targets
>
> <http://www.carbonbrief.org/analysis-how-much-is-the-uk-relying-on-negative-emissions-to-meet-its-climate-targets>
>
> <http://www.carbonbrief.org/analysis-how-much-is-the-uk-relying-on-negative-emissions-to-meet-its-climate-targets>
>
> Analysis: Is the UK relying on 'negative emissions' to ...
> <http://www.carbonbrief.org/analysis-how-much-is-the-uk-relying-on-negative-emissions-to-meet-its-climate-targets>
> www.carbonbrief.org <http://www.carbonbrief.org/>
> The Paris Agreement on climate change pledges to keep warming “well below 2C”
> and “pursue...
>
>
> Following that lead, I found an inaccuracy in reasoning that has caused BECCS
> to be the IPCC and Carbon Brief favorite. The CarbonBrief article references
> a 2010 report at this URL:
> http://www.metoffice.gov.uk/media/pdf/l/i/AVOID_WS2_D1_18_20100730.pdf
> <http://www.metoffice.gov.uk/media/pdf/l/i/AVOID_WS2_D1_18_20100730.pdf>
> where there is a fairly complete description of biochar (with BECCS and three
> other types of CDR). But those 2010 authors missed the key feature of
> biochar: out-year improved NPP benefits - not available with BECCS.
>
> 2. The unusual met office idea of biochar is seen in this half-truth
> sentence about biochar just below Table 8 on p 26 (emphasis added):
>
> " In addition compared to using the same biomass in BECCS complaint power
> stations, the net negative emissions areapproximately half. “
>
> 3. I use “half-truth” because this sentence is true only if one stops the
> analysis period upon placing the biochar in the soil. But it is grossly
> inaccurate to stop the analysis after placing char in soil - as one is
> entitled to do for BECCS. The vast majority of biochar publications are
> devoted to what happens in these out-years. Several biochar meta-studies
> suggest about a 25% average annual increase of NPP. The largest number I
> have seen reported is a 4x NPP increase
> (http://www.mdpi.com/2077-0472/5/3/723/htm
> <http://www.mdpi.com/2077-0472/5/3/723/htm>). The Terra Preta (biochar)
> soils of Brazil are reported to (still, after 500 years) double NPP and
> perhaps triple the soil’s dollar valuation.
>
> 4. So I now fear that the Carbon Brief (and many other) comparisons of
> biochar and BECCS are still based on this non-appreciation of biochar’s
> out-year ever-increasing negative emissions.
>
> Or what am I missing?
>
> Ron
>
> One other comment below.
>
>> On Apr 30, 2016, at 12:43 AM, Andrew Lockley <[email protected]
>> <mailto:[email protected]>> wrote:
>> 15 April 2016 8:52
>> Analysis: Is the UK relying on ‘negative emissions’ to meet its climate
>> targets?
>> ROZ PIDCOCK
>> 04.15.16
>
> <snip all but the last paragraph. I concur; a NET conversation/comparison is
> overdue>
>> <snip>
>> A conversation overdue
>> Negative emissions technologies, typically BECCS, are now baked into the
>> majority of the scenarios modelled by scientists showing how the world can
>> avoid breaching the 2C limit. These models tend to assume a growing amount
>> of BECCS being deployed globally from the 2040s onwards.
>> The vision for the UK is no different. The CCC has confirmed to Carbon Brief
>> that its own recommended “central scenario” for the UK’s carbon reduction
>> pathway for the decades ahead also assumes a rising amount of BECCS from
>> 2035 onwards. And yet research and development – let alone the commercial
>> upscaling of a demonstration project – is still at a tentative, early stage.
>> Given that there are still large uncertainties about the efficacy and
>> scalability of BECCS – for example, the land-use implications; the choice of
>> bioenergy crop; the safe, available storage of sequestered carbon – it seems
>> that a conversation about negative emissions among scientists, policymakers
>> and the public is overdue.
>>
>
>
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