I have written about optimally pricing methane versus CO2 from a social cost perspective where there is a risk of catastrophic damage from climate tipping events. I find results more consistent with GWP100 than GWP20 from this perspective.

bsky.app/profile/twis...

This linked-in article summarises the paper.
lnkd.in/gHZzfTkS

Policy implications. Climate: electrified and autonomous vehicles will reduce warming. Infrastructure: more car travel, less (and bigger) air travel. Competition policy: less air travel affects ticket prices. Social cohesion: brings together southeastern Australia, but not the west/east coasts.

Impacts on personal domestic aviation passengers, relative to the counterfactual. Personal air passengers in the busiest Melbourne-Sydney route reduced by 63%, with less effect on the longer Melbourne-Brisbane route. Overnight robotaxis are most used when N=4 for distances between 600 and 1000 km.

Aggregate impacts on personal domestic aviation from comparative static scenarios. Scenarios: EV=Electric vehicle, AV=Autonomous vehicles, ON=Overnight robotaxis, Cspd=Increased car speed, Tax=Carbon tax on aviation.

Elasticities vary with travel distance.

This is the main data and a simple fitted model (excludes individual route price data) for solo travellers (N=1) and groups (N>1). Marker size reflects the number of air trips. We estimate a discrete choice disutility model with car and air travel modes using Bayesian priors.

Combining in turn electrification, autonomy, the use of overnight robotaxis, a 10 kph increase in average car speeds, and an AUS$200/tCO2e carbon tax leads to personal air passenger reductions of 5%, 19%, 22%, 28% and 43%, respectively.

The densities of lines/markers in Panels A rises with battery densities (50,200,1000 Wh/kg), with blue/red representing on-ship/off-ship approaches. The panel shows fuel use per transport work relative to the "Current" scenario without a carbon price.

I need help on this (possible configurations including alongside/astern vessels like naval refuelling or tighter integration, dynamic cable limitations). I consider future scenarios (say >2040) so thoughts on where tech is heading welcome. The paper is in R&R and I hope will be available soon.

...and increase gradually as more segments electrify, while optimal battery adoption is "all-or-nothing" in the on-ship approach. The chart shows future scenarios with a US$200 carbon price. But how feasible is powering a large vessel en route through a cable?...

One advantage relates to flexibility, such as the potential for partial electrification across some segments over a long route with many stops ( I look at a China to Europe itinerary for a hybrid container ship ). Fuel reductions start at higher battery pack prices cf batteries "on-ship"...

Thanks Scott - please add me ✋

Yes please