Thread by @scianalysis

Unpacking today's great news on California's GHG progress in a brief thread:

arb.ca.gov/cc/inventory/d…

The headline you're probably hearing is accurate. CA has officially met its 2020 target early, returning GHGs to 1990 levels by 2016. This is legitimately cause for (brief) celebration. I'll pause a moment to let you bask in the warm glow. 2/

O.k. that's enough of that. Hope you enjoyed the basking, we've got work to do.

How we got here: Mainly by decarbonizing the electricity sector. Wind and solar costs declined rapidly, which allowed utilities opportunity to begin transition to renewables at bargain prices 3/

We are clearly not *done* with the electrical sector, but clearly *are* on the right trajectory. Energy efficiency and demand response will continue to play a massive role in helping accommodate more renewables. Cheap batteries will allow even deeper penetration of variable RE 4/

A 100% zero-emitting grid is very likely achievable without assuming further developments in technology. A 90-95% zero-emitting grid certainly is. Cheap zero-emitting dispatchable generation (nuclear?) or seasonal energy storage is the last piece to hit 100% 5/

On the industrial side, the next decade is going to be all about reducing high-GWP gases, like methane and HFCs. We may be reaching the end of the lowest-hanging fruit from an efficiency side (i.e. stuff that pays back in very short time period) but still lots of opportunity. 6/

The extension of cap-and-trade is absolutely critical here, as is setting program rules to limit the potential over-supply of permits. The price signal is the best opportunity to push the next wave of efficiency in industrial sector. 7/

It's important to keep investing in deep decarbonization techs. Carbon-neutral or negative cement will be a big one, as will CCS at refineries, hydrogen and ethanol production may have low-cost CCS opportunities. We need pilot projects in this space over the next decade. 8/

Transportation is now the biggest mountain to climb. People are driving more and the progress from federal fuel economy standards isn't enough to offset that (not to mention Trump/Wheeler/Pruitt's ghost may gut those anyway). 9/

CA making massive investments in EV's which will be the way of the future, though we're way behind China in that respect. Gov. Brown set a target of 5 million EVs by 2030, which is not an easy thing, but well within reach. 10/

Still, with a fleet of 25+ million passenger vehicles and a few million more heavy-duty ones, hitting that target does not, by itself, guarantee we hit our 2030 GHG target or get on a trajectory towards long-term decarbonization (i.e. 80% reduction by 2050). 11/

Need a portfolio of solutions in transportation. Electrify as much as possible. Shift urban planning to support walking/biking/transit, keep pushing fuel economy standards as much as possible. Mix in biofuels, just be careful about sustainability and land conversion as you do 12/

Quick plug for research I've worked on at NextGen, along with Ceres, UCS and others which discusses the portfolio needed for sustainability:

California's Clean Fuel Future:
nextgenamerica.org/californias-cl…

Half the oil: Pathways to Petroleum Reduction:
ucsusa.org/clean-vehicles… . 12a/

Having spent many years in sustainable transportation, I'm certain that the long-term future is pretty much all electric, and I started out as a biofuel researcher/enthusiast, so that was a slow, painful transition. But the evidence is quite clear at this point. 13/

The challenge is reducing emissions while the ZEV transition occurs, which is where efficiency, biofuels and alternatives come in. 14/

Finally, the big area of uncertainty, and frankly, the one that scares me: Natural and working lands. Agricultural emissions have stayed pretty steady over time. This may be hard to replicate as population expands and climate change makes growing conditions less favorable. 15/

We'll gain some ground as we limit methane from livestock waste and improve water use efficiency, but ultimately will probably need to transition to more regenerative agriculture to increase soil carbon and preserve production in a warming world. 16/

That we can do. Natural lands, like forests, will be tougher. Over the years, forests have been a net sink of carbon in CA. Evidence indicates that is probably no longer the case. Drought, fire and pests - for which climate change plays a massive role - are huge problem. 17/

Recent Forest Carbon Management Plan is a good first step, but it's going to take resources and attention to do it right. Everyone in CA who drinks water and breathes air has a stake in forest health. 18/

There's no clear consensus yet on ideal management of forest land under changing conditions (can't do a long term experiment when we live in the only petri dish) but understanding is improving. 19/

We may need to accept interventions which are uncertain and respond rapidly to new evidence, none of which fits well with conventional models of regulatory action in natural resource fields. 20/

All right, this no longer brief, so I'll wrap it up. Major take-home message:

Industrial economies definitely can reduce emissions without sacrificing growth. Our economy has grown over the last decade faster than national average and fast enough to move up global GDP board. 21/

In the race between advancement of clean tech and costs of deep carbon cuts, clean tech appears to be winning. We can't take for granted that this will continue forever, but we can help make sure it does with good policy. 22/

California clearly has the strongest and most comprehensive global GHG policy, though it is clearly imperfect and not so good that we can take our foot off the gas pedal... er... EV accelerator. 23/

We can do this. We can even get rich doing this. We have to keep pushing as hard as we can, and keep helping others to follow the trail we've broken. 24/24