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>
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 are approximately 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]> 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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