mthRecently I wrote (in finnish..part1 and part 2) about negative emission in IPCC scenarios and what that might imply for my home country Finland. I realized few interesting things that I wish to share also more broadly.

Integrated assessment models have a very limited technology set to play with.  In negative emissions this means maybe some changes in land use emissions and then bioenergy with CCS. When hammer is your only tool, everything starts to look like a nail. Why would CCS make sense if you can store that biomass carbon as a solid? Surely that is easier than burning the carbon and then trying to deal with the resulting volumes of gas.

In the models BECCS doesn’t have to compete agains this option since no such option is implemented. Some tens of dollars per ton of negative emissions might in fact be enough divert biomass into carbon storage and stop it being burned for energy. Pricing of negative emissions would undermine the fuel supply of all those biomass burning facilities. Implementing this option could have important implications for existing scenarios. Also, absence of this cheap carbon storage options from the models might imply severe overestimation of negative emission costs.

Screenshot 2019-03-21 at 12.07.01

From GLOBIOM land use model documentation. What about the carbon storage without burning option? I want that one.

Relatively low price also means that negative emission pricing might be much more strongly coupled to the food production than assumed. Modest payment for negative emissions might be enough to make farmers enter the negative emissions market and exit food production. This is something  whose impact should be thought through very carefully.

Those familiar with my earlier posts (for example here), know I am not too impressed by the IAM scenario factories. The observations above add to earlier criticism. Seemingly arbitrary technology restrictions and myopic focus on energy sector can have serious consequences for the usefulness of IAM generated scenarios. Models seem to treat biosphere mainly as a source of biomass for energy. Maybe, from the climate perspective, we should be seeing it more as a cheap source of negative emissions and let the energy sector fend for itself?