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Direct and indirect GWP emission
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Author:  Maillard [ Fri Jul 21, 2006 4:52 am ]
Post subject:  Direct and indirect GWP emission

For the sector Oilseed farming, the total of GWP emission is 3210 tons and the value for Oilseed farming is 2500 tons (in the second row of the table). Does this mean that the direct GWP emission is 2500 tons and the indirect GWP emission is 710 tons (3210-2500) ?
Thanks for your answer.

Author:  hscottm [ Wed Aug 09, 2006 8:33 pm ]
Post subject: 

Yvan:

Thanks for the good question.

As of today, the data for GWP looks like this (sorry it cannot be formatted much better) for $1M of Oilseed farming:

Sector - Direct Economic (%) - GWP (mt)

Total - 76.2% - 3210 mt
Oilseed Farming - 99.5% - 2500 mt
Power generation 45.1% - 202 mt
...

The first note is that "direct" in input-output terms refers to more than just "production within the sector of final demand" - it refers to all transactions made by the producer (in this case Oilseed farming sector). Thus there are direct purchases of oilseed farming, power generation, etc. These are all of the sectoral transactions needed to produce Oilseeds.

So the answer to this question is that to find the direct GWP emissions, you would multiply the "Direct %" column by the "GWP column" for each row. You'll find that it is much more than 2500 mt.

I hope this clears things up.

--

For those of you with advanced IO theory knowledge, the Leontief equation is X = [I-A]^-1 Y (where the ^-1 is the matrix inverse). However [I-A]^-1 can also be written as [I + A + A^2 + A^3 + ...]

Typically, [I+A]Y is the direct contribution (where I+A is the sum of output transactions by the Oilseed sector to make output).

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