Thread by @natehultman

1. We have released a major new report, "Fulfilling America's Pledge," that estimates the impact that actions by states, cities, & businesses can have on U.S. GHG emissions to 2025 & beyond. This thread reviews the major results. @AmericasPledge @GCAS2018 americaspledgeonclimate.com/fulfilling-ame…

2. After Trump announced his intent to withdraw from Paris in June of 2017, within 72 hours a coalition of over 2,700 cities, states, businesses, universities, faith groups and more came together to say @wearestillin. That coalition now numbers more than 3,000.

3. That coalition is not only large in number but also globally significant. It represents more than half of the U.S. population (173 million), nearly 60% of US GDP ($11.4 trillion), and if it were a country would be the world's 3rd largest economy and 4th largest GHG emitter.

4. The key question though is whether these actions can really make a difference. In other words, "What does it all add up to?" We used a combined bottom-up and top-down modeling technique to combine data on the various commitments and estimate the US emissions trajectory

5. We found that these actions can make a significant difference. We estimated the 2025 emissions outcomes from both current commitments as well as two additional levels of potential action. In the highest scenario, the US comes quite close to reaching its ambitious Paris target.

6. Let's take a look at each of the three pathways. This figure shows emissions in 2005 (far left) and where we are now (second bar, data as of 2016). Policies have already reduced emissions 12% below 2005 levels, about halfway to our Paris NDC of 26-28% below 2005.

7. The 3rd bar shows that an expected ~18% growth in GDP btwn now and 2025 would increase emissions slightly. But this is where it gets interesting: current commitments by states, cities, & businesses, & remaining Fed policies (yellow bar) would reduce emissions to 17% below 2005

8. The blue bar shows the additional reductions that could be delivered by a concerted push on 10 near-term, high impact "Climate Action Strategies" detailed here americaspledgeonclimate.com/opportunity-ag… These could drive emissions down to -21% relative to 2005 levels.

9. The purple bar shows enhanced engagement beyond just the 10 strategies, and with broader uptake. But it's still feasible under real political constraints. This scenario would bring the US very close to its Paris NDC, at 24% below 2005 levels by 2025.

10. Our Paris NDC, which I helped develop when I worked in White House for Obama Admin, was a significantly ambitious target even with full Federal action. The ability of states, cities, and businesses to come close to this target is significant.

11. This figure shows a breakdown of reductions in the three scenarios by sector. The power sector provides a significant amount of likely and potential reductions to 2025. But other sectors provide great opportunities too, and some yield benefits that increase post-2025

12. Our analysis shows that action that can be taken before 2025 by real economy actors would help build groundwork for accelerated action after 2025, bringing the pace of decarbonization to nearly the rate it would need to be to reach deep decarbonization by 2050

13. Note that we did not model new federal actions as part of this study. While federal re-engagement will be a necessary step to achieve the long-term decarbonization at the necessary pace, our research shows the impact that non-federal actors can have in the coming few years.

14. In addition, it is important to remember that the high ambition levels and the potential federal re-engagement both require new modes of collaboration as well as strong political backing. So elections matter and organizing is key.

15. And in the spirit of the #ParisAgreement, which calls on all Parties to help reach global climate goals, this approach could be of interest for other countries or actors scoping new possibilities to ratchet up ambition in advance of 2020.

16. Summary: a. Commitments in place today are significant and help keep emissions trending lower; b. With additional, feasible actions, real economy actors could drive emissions close to the ambitious 2025 Paris goal; c. these actions build groundwork for faster long term action

17. America's Pledge is led by @MikeBloomberg and @JerryBrownGov. The vice-chairs are @MaryNicholsCA and @CarlPope. More details about the AP structure are in the report.

18. The research & report were co-led by myself (with the Center for Global Sustainability @CtrGlobSust team at the U of Maryland) and by @bodnarclimate, Koben Calhoun and team at @RockyMtnInst. Partners: @WorldResources @ACEEEdc @CDP @EnvDefenseFund @BloombergDotOrg and CA team.

19. The report is available via the link and contains full descriptions of these results as well as some cool case studies. And for those of you who really want to dig into the numbers and assumptions, you can find a Technical Appendix. americaspledgeonclimate.com/fulfilling-ame…