Emissions paths consistent with

Transcription

1 Emissions paths consistent with Market Cost of Renewable Jet Fuel Adoption in the US remaining below 2 degrees C John Reilly MIT Global Change Forum XLI March 27, 218 Thanks to Jennifer Morris and Andrei Sokolov

2 Emissions paths consistent with remaining below 2 Emissions degrees C Much of the focus is on emissions through 25 quite reasonable. But what we assume is possible after 25 determines how much we need to do now through 25. My story: How do assumptions about when we start forest sinks BECCs ability to get to zero fossil emissions post-25 climate uncertainty affect emissions 2

3 Method: Apply the MIT IGSM and some simple assumptions about abatement post 25 Hydrology/ water resou rces Volcanic forcing Solar forcing Human System Land use change Emissions Prediction and Policy Analysis (EPPA) National and/or Regional Economic Development, Emissions & Land Use Agricultu re, forestry, bio-energy, ecosystem productivi ty Earth System Trace gas fluxes (CO2, CH4, N2O) and poli cy const raints Atmosphere 2-Dimensional Dynamica l, Physical & Chemical Processes Ocean 2- or 3-Dimensional Dynamica l, Biolo gical, Chemical & I ce Processes CO2, CH4,CO, N2O, NOx, SOx, NH3, CFCs, HFC s, PFCs, SF6, VOC s, BC, e tc. Coupled Ocean, Atmosphere, and Land Human health effects Urban Airshed Air Pollution Processes Clim ate/ energy demand Land Water & Energy Budgets (CLM) Biogeochemical Processes (TEM & NEM) Sea level change The MIT Integrated Global System Model (IGSM) Exchanges represented in standa rd runs of the s ystem Exchanges utili zed in ta rgeted studies Impleme ntation of feedbacks is under de velopme nt 3

4 Scenarios 1. Global carbon price starting in 22, constant in net present value dollars through time i.e. rising at a 4% discount rate. 2. Paris through 225, global carbon price phased in from Avoided deforestation and land sinks contribute 21 Gt of abatement (Reilly et al, 212), allowing extra headroom for other emissions equally from Forest and land contribution of 21 Gt with all the headroom used from BECCS of 25 Gt (mid range of IPCC) cumulative after 25, headroom used from Net zero fossil energy emissions after 27, extra headroom used from (Difficult-to-reduce methane from livestock/rice, nitrous oxide from fertilizer remain in the post 27 period.) 2 C with a 5/5 chance, and with a 67% likelihood 4

5 Global Emissions & Temperature Change, Paris Forever Paris Forever ºC Sokolov, et al., 217, JP Report No. 32 5

6 Global Emissions & Temperature Change, 2 C Starting in 22 2º Tax starting in Paris Forever 2º Tax starting in ºC 6

7 Global Emissions & Temperature Change, Paris to 2C 2º Tax starting in Paris Forever 2º Tax starting in 22 Paris to 2º ºC 7

8 Emissions Pathways to 2C: Paris to 2C Paris to 2º

9 Emissions Pathways to 2C: New Forest Uptake Paris to 2º 1 Forest Sink 21 Gt thru

10 Emissions Pathways to 2C: New Forest Uptake Paris to 2º 1 Forest Sink 21 Gt thru 21 Forest Sink 21 Gt thru

11 Emissions Pathways to 2C: Paris to 2C Paris to 2º

12 Emissions Pathways to 2C: BECCS Paris to 2º 1 BECCS, 26 GT after

13 Emissions Pathways to 2C: Net Zero Fossil Paris to 2º 1 BECCS, 26 GT after 25 Fossil, net zero post

14 Emissions Pathways to 2C: Carbon Prices º Tax starting in 22 Paris to 2º Forest Sink 21 Gt thru 21 Forest Sink 21 Gt thru 26 BECCS, 26 GT after 25 Fossil, net zero post Pathway to 2C 23 Emissions Price ($/mmt CO2-eq) 2º Tax ($5) starting in Paris to 2º 16 Forest Sink 21 Gt thru Forest Sink 21 Gt thru 26 5 BECCS, 26 GT after Fossil, net zero post

15 2C vs. 2C Likely: Global Emissions & Temperature Change Likely 2º Tax starting in º Tax starting in 22 2º Likely Tax starting in ºC 15

16 2C vs. 2C Likely: Global Emissions & Temperature Change Likely 2º Tax starting in º Tax starting in 22 2º Likely Tax starting in 22 Paris to 2º ºC Paris to 2º Likely 16

17 Emissions Pathways: 2C vs. 2C Likely Paris to 2º Paris to 2º Likely Forest Sink 21 Gt thru 21 2º Likely Forest Sink 21 Gt thru 21 Forest Sink 21 Gt thru 26 2º Likely Forest Sink 21 Gt thru 26 BECCS, 26 GT after 25 2º Likely BECCS, 26 GT Fossil, net zero post 27 2º Likely Fossil, net zero post 27 17

18 Carbon Prices: 2C vs. 2C Likely 23 Emissions Price ($/mmt CO2-eq) Pathway to 2C 2º 2º Likely 2º Tax($5,64) starting in Paris to 2º Forest Sink 21 Gt thru Forest Sink 21 Gt thru BECCS, 26 GT after Fossil, net zero post

19 Summary Is Paris consistent with 2 C path? Yes, more or less if optimistic about net zero, BECCs, forest or land use sinks in the post 25 period Or some more modest combinations of these assumptions. And we need a comprehensive global carbon policy starting soon that goes well beyond the Paris Agreement However, if we could do more sooner, the needed CO 2 price would be ~$3/tonne lower. But if we want to increase the likelihood of remaining below 2 C to 67%, then it makes job harder, adding $5-$2 to the starting carbon price (less if there is more headroom in early 19 years).

20 Thank You 2

21 Emissions Pathways and Temperature Change Surface air temperature relative to mean 2.5 Paris to 2º Forest Sink 21 Gt thru ºC