The Biden Administration has committed the United States to net-zero emissions by 2050. Meeting this commitment requires drastic decarbonization transitions across all sectors of society at a pace never seen before. This can be made possible by positive tipping points, which demarcate thresholds in decarbonization transitions that, once crossed, ensure rapid progress towards completion. A new generation of economic models enables the analysis of these tipping points and the evaluation of effective policy interventions.
The Biden Administration should undertake a three-pronged strategy for leveraging the power of positive tipping points to create a larger-than-anticipated return on investment in the transition to a clean energy future. First, the President’s Council of Advisors on Science and Technology (PCAST) and the Council of Economic Advisors (CEA) should evaluate new economic models and make recommendations for how agencies can incorporate such models into their decision-makingprocess. Second, federal agencies should integrate positive tipping points into the research agendas of existing research centers and programs to uncover additional decarbonization opportunities. Finally, federal agencies should develop decarbonization strategies and policies based on insights from this research.
Challenge And Opportunity
Climate change brings us closer each year to triggering negative tipping points, such as the collapse of the West Antarctic ice sheet or the Atlantic Meridional Overturning Circulation. These negative tipping points, driven by self-reinforcing environmental feedback loops, significantly accelerate the pace of climate change.
Meeting the Biden Administration’s commitment to net-zero emissions by 2050 will reduce the risk of these negative tipping points but requires the United States to significantly accelerate the current pace of decarbonization. Traditional economic models used by the federal government and organizations such as the International nergy Agency consistently underestimate the progress of zero-emission technologies and the return on investment of policies that enable a faster transition, resulting in the agency’s “largest ever upwards revision” last year. A new school of thought presents “evidence-based hope” for rapidly accelerating the pace of decarbonization transitions. Researchers point out that our society consists of complex and interconnected social, economic, and technological systems that do not change linearly under a transition, as traditional models assume; rather, when a positive tipping point is crossed, changes made to the system can lead to disproportionately large effects. A new generation of economic models has emerged to support policymakers in understanding these complex systems in transition and identifying the best policies for driving cost-effective decarbonization.
At COP26 in 2021, leaders of countries responsible for 73% of world emissions, including the United States, committed to work ogether to reach positive tipping points under the Breakthrough Agenda. The United Kingdom and other European countries have led the movement thus far, but there is an opportunity for the United States to join as a leader in implementing policies that intentionally leverage positive tipping points and benefit from the shared learnings of other nations.
Domestically, the Inflation Reduction Act (IRA) and the Infrastructure Investment and Jobs Act (IIJA) include some of the strongest climate policies that the country has ever seen. The implementation of these policies presents a natural experiment for studying the impact of different policy interventions on progress towards positive tipping points.
How do positive tipping points work?
Figure 1. Diagram of a system and its positive tipping point. The levers for change on the left push the system away from the current high-emission state and towards a new net-zero state. As the system moves away from the current state, the self-reinfocing feedback loops in the system become stronger and accelerate the transition. At the positive tipping point, the feedback loops become strong enough to drive the system towards the new state without further support from the levers for change. Thus, policy interventions for decarbonization transitions are most crucial in the lead up to a positive tipping point. (Adapted from the Green Futures Network.)
Just as negative tipping points in the environment accelerate the pace of climate change, positive tipping points in our social, economic, and technological systems hold the potential to rapidly accelerate the pace of decarbonization (Figure 1). These positive tipping points are driven by feedback loops that generate increasing returns to adoption and make new consumers more likely to adopt (Figure 2):
Learning by doing: As manufacturers produce more of a technology, they learn how to produce the technology better and cheaper, incentivizing new consumers to adopt it.
Economies of scae: Manufacturers are able to realize cost savings as they increase their production capacity, which they pass on to consumers as lower prices that spur more demand.
Social contagion: The more people adopt a new technology, the more likely other people will imitate and adopt it.
Complementary technology reinforcement: As a technology is adopted more widely, complementary technology and infrastructure emerge to make it more useful and accessible.
The right set of policies can harness this phenomenon to realize significantly greater returns on investment and trigger positive tipping points that give zero-emission technologies a serious boost over incumbent fossil-based technologies.
Figure 2. Examples of positive feedback loops: (a) learning by doing, (b) social contagion, and (c) complementary technology reinforcement.
One way of visualizing progress towards a positive tipping point is the S-curve, where the adoption of a new zero-emission technology grows exponentially and then satuates at full adoption. This S-curve behavior is characteristic of many historic energy and infrastructure technologies (Figure 3). From these historic examples, researchers have identified that the positive tipping point occurs between 10% and 40% adoption. Crossing this adoption threshold is difficult to reverse and typically guarantees that a technology will complete the S-curve.
Figure 3. The historic adoption of a sample of infrastructure and energy systems (top) and manufactured goods (bottom). Note that the sharpness of the S-curve can vary significantly. (Source: Systemiq)
For example, over the past two decades, the Norwegian government helped build electric vehicle (EV) charging infrastructure (complementary technology) and used taxes and subsidies to lower the price of EVs below that of gas vehicles. As a result, consumers began purchasing the cheaper EVs, and over time manufacturers introduced new models of EVs that were cheaper and more appealing than previous models (lerning by doing and economies of scale). This led to EVs skyrocketing to 88% of new car sales in 2022. Norway has since announced that it would start easing its subsidies for EVs by introducing two new EV taxes for 2023, yet EV sales have continued to grow, taking up 90% of total sales so far in 2023, demonstrating the difficult-to-reverse nature of positive tipping points. Norway is now on track to reach a second tipping point that will occur when EVs reach price parity with gas vehicles without assistance from taxes or subsidies.
Due to the interconnected nature of social and technological systems, triggering one positive tipping point can potentially increase the odds of another tipping point at a greater scale, resulting in “upward-scaling tipping cascades.” Upward-scaling tipping cascades can occur in two ways: (1) from a smaller system to a larger system (e.g., as more states reach their tipping point for EV adoption, the nation as a whole gets closer to its tipping point) and (2 from one sector to another. For the latter, researchers have identified three super-leverage points that policymakers can use to trigger tipping cascades across multiple sectors:
Light-duty EVs → heavy-duty EVs and renewable energy storage: The development of cheaper batteries for light-duty EVs will enable cheaper heavy-duty EVs and renewable energy storage thanks to shared underlying battery technology. The build-out of charging infrastructure for light-duty EVs will also facilitate the deployment of heavy-duty EVs.
Green ammonia → heavy industries, shipping, and aviation: The production of green ammonia requires green hydrogen as an input, so the growth of the former will spur the growth of the latter. Greater production of green hydrogen and green ammonia will catalyze the decarbonization of the heavy industries, shipping, and aviation sectors, which use these chemicals as fuel inputs.
Traditional and alternative plant proteins → land use: Widespread consumption of traditional an alternative plant proteins over animal protein will reduce pressure on land-use change for agriculture and potentially restore significant amounts of land for conservation and carbon sequestration.
The potential for this multiplier effect makes positive tipping points all the more promising and critical to understand.
Further research to identify positive tipping points and tipping cascades and to improve models for evaluating policy impacts holds great potential for uncovering additional decarbonization opportunities. Policymakers should take full advantage of this growing field of research by integrating its models and insights into the climate policy decision-making process and translating insights from researchers into evidence-based policies.
Plan Of Action
In order for the government to leverage positive tipping points, policymakers must be able to (1) identify positive tipping points and tipping cascades before they occur, (2) understand which policies or sequences of policis may be most cost-effective and impactful in enabling positive tipping points, and (3) integrate that insight into policy decision-making. The following recommendations would create the foundations of this process.
Recommendation 1. Evaluate and adopt new economic models
The President’s Council of Advisors on Science and Technology (PCAST) and the Council of Economic Advisors (CEA) should conduct a joint evaluation of new economic models and case studies to identify where new models have been proven to be more accurate for modeling decarbonization transitions and where there are remaining gaps. They should then issue a report with recommendations on opportunities for funding further research on positive tipping points and new economic models and advise sub agenciessubagencies responsible for modeling and projections, such as the Energy Information Administration within the Department of Energy (DOE), on how to adopt these new economic models.
Recommendation 2. Integrate positive tiping points into the research agenda of federally funded research centers and programs.
There is a growing body of research coming primarily from Europe, led by the Global Systems Institute and the Economics of Energy Innovation and Systems Transition at the University of Exeter and Systemiq, that is investigating global progress towards positive tipping points and different potential policy interventions. The federal government should foster the growth of this research area within the United States in order to study positive tipping points and develop models and forecasts for the U.S. context.
There are several existing government-funded research programs and centers that align well with positive tipping points and would benefit synergistically from adding this to their research agenda:
Power, buildings, and heavy industries: The National Renewable Energy Laboratory (NREL), funded by the DOE, has an energy analysis research program that conducts analyses of future systems scenarios, arket and policy impacts, sustainability, and techno-economics. This research program would be a good fit for taking on research on positive tipping points in the power, buildings, and heavy industries sectors.
Transportation: The National Center for Sustainable Transportation (NCST), funded by the Department of Transportation, conducts research around four research themes—Environmentally Responsible Infrastructure and Operations, Multi-Modal Travel and Sustainable Land Use, Zero-Emission Vehicle and Fuel Technologies, and Institutional Change—in order to “address the most pressing policy questions and ensure our research results are incorporated into the policy-making process.” The policy-oriented focus of the NCST makes it a good candidate for conducting research on positive tipping points in the transportation sector under the theme of Institutional Change and translating research results into policy briefs.
Food and agriculture: The Agriculture and Food Research Initiative’s Sustaiable Agriculture Systems program funds research projects that take a systems approach to studying how to promote transformational change in the U.S. food and agriculture system in the face of a changing climate. In the next Request for Applications, the program should include research on positive tipping points in food and agricultural systems as a topic that the program will fund.
General: The Science and Technology Policy Institute (STPI), a Federally Funded Research and Development Center (FFRDC) sponsored by the National Science Foundation, conducts research to inform policy decisions by the White House Office of Science and Technology Policy. STPI is another potential candidate for conducting research on positive tipping points in a variety of sectors.
Recommendation 3. Use insights from positive tipping points research to develop and implement policies to accelerate progress towards positive tipping points
Researchers have already identified three super-leverage points around whch the federal government should consider developing and implementing policies. As future research is published, the PCAST should make further recommendations on actions that the federal government can take in leveraging positive tipping points.
Super-Leverage Point #1: Mandating Zero-Emission Vehicles (ZEVs)
ZEV mandates require car manufacturers to sell a rising proportion of ZEVs within their light duty vehicles sales. Ensuring a growing supply of ZEVs results in falling costs and rising demand. Evidence of the effect of such policies in U.S. states, Canadian provinces, and China and future projections suggest that ZEV mandates are a crucial policy lever for ensuring a full EV transition. Such policies rely on the reallocation of private capital rather than government spending, making it particularly cost-effective. Combined with the investments in EV manufacturing and public charging infrastructure in the IRA and IIJA, a national ZEV mandate could radically boost the EV transitio.
A national ZEV mandate is unlikely to pass Congress anytime soon. However, the recently proposed Environmental Protection Agency (EPA) greenhouse gas emissions standards for passenger cars and trucks would effectively require 67% of car sales to be ZEVs by 2032 in order for car manufacturers to comply with the regulations. The proposed standards would provide regulatory strength behind the Biden Administration’s goal of 50% of new cars sold by 2030 to be ZEVs. The EPA should finalize these standards as soon as possible at or above the currently proposed stringency.
The proposed EPA standards are projected to result in a 50% reduction in the price of EV batteries by 2035. This will have knock-on effects on the cost of batteries for renewable energy storage and battery electric trucks and other heavy-duty vehicles, which would likely bring forward the cost parity tipping point for these technologies by a number of years.
Super-Leverage Point #2: Mandating Green Ammonia Use In Fertlizer Production
Ammonia is the primary ingredient for producing nitrogen-based fertilizer and requires hydrogen as an input. Traditionally, this hydrogen is produced from natural gas, and the production of hydrogen for ammonia accounts for 1% of global CO2 emissions. Green hydrogen produced from water and powered by renewable energy would enable the production of green ammonia for nitrogen-based fertilizers.
Based on a DOE tipping point analysis, green ammonia production is one of the most promising areas for initial large-scale deployment of green hydrogen, thanks to its ability to use established ammonia supply chains and economies of scale. Green ammonia production also has one of the lowest green premia in the hydrogen economy. Green ammonia production will enable infrastructure development and cost reductions for green hydrogen to decarbonize other sectors, including shipping, aviation, and heavy industries like steel.
The Biden Administration should set a target for green amonia production for domestic fertilizer in the Federal Sustainability Plan similar to India’s draft hydrogen strategy requiring 20% green ammonia production by 2027–2028. The EPA should then propose Clean Air Act carbon emission limits and guidelines for nitrogen-based fertilizer production plants, similar to the recently proposed standards for coal and natural gas power plants, to provide regulatory strength behind that target. These limits would effectively require fertilizer plants to blend a growing percentage of green ammonia into their production line in order to meet emission limits. According to the DOE, the clean hydrogen production tax credit in the IRA has enabled cost parity between green ammonia and fossil-based ammonia, so the EPA should be able to set such limits without increasing food production costs.
Super-Leverage Point #3: Public Procurement To Promote Plant And Alternative Proteins
Shifting protein consumption from meat to plant and alternative proteins can reduc emissions from livestock farming and reduce land use change for meat production. Plant proteins refer to protein-rich plants, such as nuts and legumes, and traditional products made from those plants, such as tofu and tempeh. Alternative proteins currently on the market include plant- and fermentation-based protein products intended to mimic the taste and texture of meat. Studies show that if plant and alternative proteins are able to reach a tipping point of 20% market share, this would ease up 7–15% of land currently used for agriculture to conservation and the restoration of its ability to serve as a carbon sink.
Public procurement of alternative proteins for federal food programs leverages government spending power to support this nascent market and introduce new consumers to alternative proteins, thus increasing its accessibility and social traction. Last year, the National Defense Authorization Act established a three-year pilot program for the U.S. Navy to offer alternative potein options. The California state legislature also invested $700 million to support schools in procuring more plant-based foods and training staff on how to prepare plant-based meals.
The United States Department of Agriculture (USDA) is a major procurer of food through collaboration between the Agricultural Marketing Service (AMS) and the Food and Nutrition Service (FNS) and distributes the majority of procured food through the Child Nutrition Programs (CNPs), especially the National School Lunch Program (NSLP). Currently, AMS does not procure any traditional or alternative protein products made from plant protein, but USDA guidelines do allow traditional and alternative protein products to fulfill meat/meat alternate requirements for CNPs. The AMS should develop product specifications and requirements for procuring these types of products and assist traditional and alternative protein companies to become USDA food vendors. The FNS should then launch a pilot program spending, for eample, 1% of their procurement budget on traditional and alternative protein products. This should be supported by education and training of food service workers at schools that participate in the NSLP on how to prepare meals using traditional and alternative proteins.
Conclusion
The sooner that positive tipping points that accelerate desired transitions are triggered, the sooner that decarbonization transitions will be realized and net-zero goals will be met. Early intervention is crucial for supporting the growth and adoption of new zero-emission technologies. The recommendations above present the foundations of a strategy for leveraging positive tipping points and accelerating climate action