Emily Cunningham

2. So, some things I've been mulling over. First, carbon pricing is a weird and mutable idea. In usage, it can mean everything from abstract emissions quotas to a literal carbon dioxide tax.

3. Second, that mutability grows when we start to consider "internal prices" on carbon. That's where folks consider the impact on their organization of future carbon prices, and test their strategies against a world in which they have to pay those prices.

4. One of the key concepts there is that the carbon price (say, $10/tonne of CO2) is not a precision prediction, but a stand-in for a range of possible pressures on the use of fossil fuels, and other climate-endangering activities.

5. (There's some excellent work on all this from groups like @CDP @CarbonBubble @NewClimateEcon @WorldResources @SEIresearch and others... I'm giving the most cursory overview here...)

6. That stand-in price function, though—that ability to model impacts of many kinds through simply assuming emissions will have costs—is really valuable, conceptually. It can serve as a shorthand for the impacts of climate action in general on a specific institution's operations

7. Some companies and analysts have begun running higher (stand-in virtual/internal) carbon prices as a way to see what could happen with more aggressive climate policies. I have a whole thing I'm working on about this idea, so stay tuned.

8. What I find most interesting, though, is the work showing that even fairly low national/global carbon prices exert enough pressure on a lot high-carbon economic activities to make them unprofitable.

9. While very high prices—say, $200/tonne carbon taxes—might be needed to achieve deep decarbonization through economic incentives alone, fairly low prices (say, $30 a tonne) are disruptive to a fair number of dirty companies/practices.