Katarina Zimmer is a freelance science and environment journalist based in Germany.
Our planet is a dynamic place. In its 4.5-billion-year history, it has remade itself again and again, snapping from hot to cold, oxygen-poor to oxygen-rich, often modeled by life itself. Several times, polar glaciers rushed over the Earth, turning it into a giant snowball. At one point, its mundane atmosphere swelled with oxygen, making it what we know today.
Researchers who study Earth’s history, like climate scientist Tim Lenton of the University of Exeter in the UK, know that some of these shifts, contrary to the slow and steady forces driving them, did not occur smoothly and gradually. These changes were instead the product of pivotal, transformational moments — tipping points — that triggered them.
Today, the mention of climate tipping points evokes anxiety for Lenton and other scientists who anticipate similarly outsized effects caused by humanity’s influence on Earth’s atmosphere. By that, Lenton isn’t referring to the increasingly extreme droughts, heatwaves and hurricanes that have unfurled across the world in recent years; at least up until this year’s extreme weather events, such trends have been a logical product of the human-caused steady increase in global temperatures. Rather, he’s worried about particular areas within our climate system that are likely to dramatically overreact — or tip — due to this warming.
Take the Jakobshavn Glacier in Greenland, for instance. Once it passes a certain threshold of warming, scientists predict its melting will rapidly accelerate. Partly at fault is the fact that as it drops in height, the glacier’s surface becomes exposed to warmer temperatures and snowline retreat reveals darker ice that then soaks up more energy. Melting begets melting — a downward spiral that continues until the glacier disappears.
Similar acceleration processes portend the collapse of the Antarctic ice sheet, critical ocean circulations and the Amazon rainforest, raising sea levels, disrupting climate patterns and amplifying global warming because of the important role many of these systems play in Earth’s climate.
But to Lenton it also seemed logical that to the same degree the climate is capable of dramatic shifts, human society might also be capable of undergoing its own rapid transformations — but in this case, perhaps, in a positive direction.
With this possibility in mind, his team and several others have spent the past few years seeking out and identifying several “positive tipping points” in the global economy and society that, once achieved, could trigger a rapid transition away from emitting greenhouse gases.
Some countries have already achieved such exponential shifts through the adoption of electric vehicles and the phasing out of coal-generated power — by enacting relatively modest policies that enabled greener options to effectively outcompete carbon-intensive technologies on the market.
There’s even evidence at the global level that car manufacturing and power generation, which together produce more than a third of the world’s emissions, are already on the verge of passing positive tipping points. These industries just need a nudge from policymakers, who can provide incentives for consumers and industry to further adopt cleaner technologies.
Lenton believes that because policymakers have been stuck on the idea that technological progress occurs slowly and steadily, they have failed to help evolve more rapid shifts. But his research suggests that technological change can occur very quickly with policies that get green technologies to “tipping point” thresholds — and that this could turbocharge the green transition.
The recently passed Inflation Reduction Act (IRA) and some policies in the EU are already a step in the right direction. Tipping points aren’t a silver bullet. There’s still a lot of work to be done, especially around achieving these shifts in an equitable way that, for instance, doesn’t exacerbate the poor working conditions and environmental degradation caused by mining in those developing countries that help supply many of the crucial metals fueling the green transition. But it’s also possible that a tipping point approach gets us closer to the kind of transformational change we need.
In fact, Lenton believes our best chance of avoiding negative tipping points is harnessing positive ones. After all, history tells us that technological change can happen very rapidly; consider the development of the steam engine in the 17th and 18th centuries that kick-started the Industrial Revolution in England, or the transition from horse-drawn carriages to fossil fuel-powered cars in the early 1900s.
In today’s economy, Lenton first saw convincing evidence of such rapid shifts in the UK. In the past decade, the country has transformed its power sector by almost fully phasing out coal power which it had previously used to produce 40% of its electricity. As a result, the UK’s carbon emissions fell faster than any other large country in the world.
One key to making this happen was a rapid, government-subsidized expansion of solar and wind power infrastructure, which meant that coal and gas industries were competing over a smaller slice of the pie, says climate policy expert Simon Sharpe, who collaborates with Lenton on researching positive tipping points.
But the nail in the coffin was a carbon tax the government introduced in 2013, charging companies around $14 and later $27— for every ton of carbon it burned, Sharpe believes. Though modest, it was just enough to create a tipping point where coal, the most carbon-intensive form of energy, became more costly to burn than gas. “It meant that [for much] of the time, the coal plants would be sitting there unused,” says Sharpe, a senior fellow at the World Resources Institute.
By around 2015, running a coal plant in the UK had become entirely unprofitable. To Sharpe, the story clearly demonstrates that effective pricing is necessary to ensure “that the clean option becomes cheaper than the dirty option.”
Meanwhile, Norway has seen an unparalleled per capita adoption of electric vehicles with some 80% of new cars sold in Norway — and around 20% of all cars on its roads — fully electric.
This outcome is the result of Norwegian government policy originating in the 1990s when it made a tweak to the purchase taxes for vehicles: it decided to remove these taxes on EVs but leave them in place for petrol and diesel vehicles. For the first two decades, the only available electric vehicles had relatively short driving ranges due to battery limitations, and it was often urban commuters in Oslo who bought them, incentivized by policies that allowed access to bus lanes and provided free charging and parking in the city center. Combined with lower costs for EVs to access toll roads, changes like these made EVs a cheaper option for some commuters as early as 2011. Passing this tipping point encouraged more and more Norwegians to opt for EVs over time, especially as the costs of manufacturing batteries dropped and more affordable cars with greater ranges became available. Once a certain number of EVs were on the road, private companies stepped in to rapidly build out public charging stations.
The policy’s success was not a sure bet, notes Christina Bu, the secretary general of the Norwegian EV Association. Many Norwegians are still skeptical about climate change, and the population is sparsely distributed across an area the size of Montana, which makes it difficult to adequately distribute charging stations for longer trips. But even so, “it’s almost silly how easy this has been,” Bu says. “Why aren’t just more countries doing something similar?”
A New Climate Strategy
Both Lenton and Sharpe believe these cases illustrate just how rapidly green technologies can spread. When such technologies first arrive on the market, they’re often too expensive or otherwise unappealing to buy. But gradually, beneficial economic processes kick in: The more frequently something is made, the more cheaply, efficiently and effectively the product and process typically becomes. It’s also more likely that other technologies emerge to help improve its function, such as EV charging stations or battery infrastructure for solar farms, which are critical to ensuring a steady supply.
Once more people are buying something that provides them with a positive experience, like the substantial savings on gasoline and overall energy costs — the more their friends and neighbors also become interested in such purchases.
In the same way that melting begets melting for Greenland’s Jakobshavn Glacier, green technologies can also spread in a self-reinforcing manner. And once they pass that tipping point where they’re more attractive than their fossil fuel incumbents, they can take over the market. As the UK and Norway show, governments can accelerate these tipping points with policies that make greener options more viable.
Eventually, Lenton and Sharpe hope green technologies will be so commonplace that governments can relax incentives; carbon-emitting technologies simply won’t stand a chance or can eventually be banned, locking the economy into a greener state, Sharpe says.
But mainstream economists and policymakers frequently fail to predict rapidly evolving market conditions; instead, they have long viewed the economy as a static system that changes slowly and incrementally. This ignores the reality of how quickly innovations can spread, Sharpe says. As a result, policymakers haven’t tried to proactively create tipping points. Instead, they have often focused, for instance, on figuring out how high a carbon tax should be, reasoning that if the price of carbon reflects its true cost to society, the market will correct itself.
For Sharpe, the UK’s example shows that it’s not the exact price of carbon that matters, but its cost relative to green technologies; only this has the power to fundamentally alter the market. And in any case, he adds, investing in new technologies is generally a more effective approach to making products better and cheaper than taxing the old technologies.
This approach requires a more holistic manner of governing, one that considers future market and technology changes. For a long time governments chose to invest mostly in fossil fuels because they were cheaper, notes sustainability transitions expert Frank Geels of the University of Manchester, and failed to foresee that the cost of green technologies would eventually decrease to the point where they are viewed as a better long-term option.
“Most of the time, what we see in the data and the forecasts is that people underestimate how quickly technological progress happens and how quickly cost reductions take place,” Sugandha Srivastav, an environmental economist at the University of Oxford, tells me. “Humans are famously bad at understanding exponential trends.”
A case in point, the price of lithium-ion batteries — important for efficient electric vehicles and storing solar and wind energy — plummeted by about 90% over the past decade or so, faster than many analysts predicted. Projections made roughly a decade ago far underestimated the price drops of solar cells and deployment. Prices actually dropped by more than five times the predicted amount, or 15% annually, and global solar capacity has increased 10 times beyond what analysts originally predicted. Meanwhile, as global sales for fully electric and hybrid vehicles have grown by about 40% annually over the last decade, costs have fallen by around 17% each year.
EVs are now nearing a global tipping point. In fact, Aileen Lam, an environmental economist at the World Bank, told me she believes “most countries either have passed it or they’re going to pass it in a few years.” Lam recently coauthored a preliminary analysis of several leading car markets. In China, for instance, EV prices have dipped below that of their competitors for several major vehicle types. In the EU and the US, there’s still a roughly $10,000 to $20,000 difference in price tag between the average cost of an EV and a traditional combustion-engine vehicle, not including any government-funded rebate programs.
Still, some models have crossed the adoption threshold: In the U.S., Tesla’s Model 3 now costs around $40,000, about $8,000 less than the average cost of a traditional new car. In India, too, the overall prices of electric cars are rapidly approaching those of conventional cars. Perhaps even more important would be price declines for more affordable options like electric motorbikes, scooters and rickshaw taxis, which make up the bulk of the vehicles on Indian roads, Srivastav adds.
Efforts to produce renewable energy are even further along. In much of the world, it’s already cheaper to build a new solar or wind plant than it is to build a new coal or gas facility, without even accounting for renewable energy subsidies. We’re now just passing a point where building new renewable facilities is cheaper than operating existing fossil fuel plants. And some experts estimate that the world is just a few years away from hitting another tipping point: when solar and wind are the cheapest forms of energy even when accounting for storage costs.
Solar and wind now account for more than three-quarters of the new energy capacity of facilities built around the world. Adoption has skyrocketed in some developing countries; Chile, for instance, now gets nearly a fifth of its energy from solar. Using hydropower and geothermal energy has also helped many countries slash carbon emissions — like Iceland, Costa Rica and Kenya, where much of their electricity comes from these renewable sources.
But building geothermal or hydropower facilities is a much larger industrial undertaking than setting up solar panels or wind turbines, and does not necessarily result in similar cost decreases as deployment increases, Srivastav says. Another possible reason for this is that the best geothermal and hydropower sites are often tapped first, meaning that there could be diminishing returns for further development. Nuclear power development also hasn’t shown the trend of declining costs, she adds.
In the U.S., wind and solar combined now generate more than 13% of total electricity production, just above the global average of 12%. Notably, it’s predominantly Republican-leaning red states that get the highest percentage of their energy from wind, largely because they benefit from cheaper land and easier permitting processes compared to blue states.
In Texas, the nation’s leader in wind power generation, “people are building wind not because of the environment as much as they’re building wind because they make more money when they have wind power,” says David Victor, an expert in technological innovation and public policy at the University of California, San Diego.
Harnessing Tipping Points
Meanwhile, the cost of energy derived from fossil fuels, though volatile in the short term, has remained broadly flat over the past few decades. These fuels can be expensive to extract and often rely on hefty government subsidies. The International Renewable Energy Agency reports that in 2020, governments around the world poured just under half a trillion dollars into subsidies for fossil fuels — more than three times what they spent on subsidizing renewables. The economic benefits of transitioning to renewables would be immense, Srivastav says. Some estimate that thanks to the rapid declines in the cost of renewable energies, shifting away from fossil fuels “will likely result in [an] overall net savings of many trillions of dollars.” That doesn’t even account for the climate damage that sticking with fossil fuels will inevitably cause.
The rapid uptake of renewable energy so far is already helping to bend the global emissions curve for power generation downwards. But both renewable energy and EVs will need a boost from policymakers to bring them more quickly to the point where they can outcompete fossil fuel incumbents. That boost could take a range of forms, including taxation, favorable loans, subsidies or tax credits — as long as it functionally affects the relative pricing of green technologies in comparison to their alternatives, Sharpe says. Where possible, even harsher measures, like mandating a gradual phasing out of internal combustion engines, as California and the E.U. have done, can also help drive industry shifts, Sharpe says.
Of course, fiscal policies must be accompanied by efforts to build out energy storage and electricity grid infrastructure capable of handling vast quantities of less reliable forms of energy like wind and solar. In the U.S., there’s an urgent need to find faster ways of connecting solar and wind plants to the grid; right now, thousands of renewable plants are waiting in yearslong queues to be linked up to the grid due to lengthy permitting processes and a lack of transmission lines, notes James Gerber, a senior scientist with the climate solutions non-profit Project Drawdown.
“There’s a really stupendous amount of [renewable] capacity that’s just waiting,” notes Gerber. Similarly, greater public uptake of electric vehicles hinges on public and private investment into charging infrastructure. The lack of such funding is one reason why EV adoption has lagged in the U.S., which is especially problematic given Americans’ tendency toward larger vehicles and more sprawling cities.
The IRA has enabled progress toward reducing some of these barriers; Of the $369 billion in funds it contains for climate and energy policies, roughly $270 billion are tax credits for clean vehicles, charging infrastructure, solar and wind farms, domestic battery manufacturing and the training of skilled laborers, among other climate solutions.
But “there’s going to be other emergent barriers,” says Erin Mayfield, an expert in energy systems at the Thayer School of Engineering at Dartmouth. Whether or not the provisions within the act are enough to address those, remains to be seen, she says.
Because economies are global and intertwined, many experts note that everyone can benefit when someone makes progress. California’s recent EV mandate — which aims to have all new vehicles sold in the state release zero emissions by 2035 — has already inspired some other states to adopt similar measures, especially given the state’s economic size: California is the fifth largest economy globally.
The IRA itself, which also contains requirements to encourage domestic manufacturing of green tech, has spurred other countries to take similar measures; the EU recently announced its Green Deal Industrial Plan, which aims to boost the manufacture of net-zero technologies in Europe, among other goals. This is now spurring a global green tech innovation race between China, the U.S. and Europe, Geels says.
And in general, more EVs mean more batteries must be produced, which means the batteries will cost less, enable cheaper storage and lead to, ultimately, more renewable energy. (Of course, this presumes there is a steady metal supply to manufacture said batteries.) According to some estimates, each time the collective global amount of solar and wind energy doubles, their costs fall by around 28% and 15%, respectively.
Countries can work together to accelerate these shifts even further. For instance, Lam’s study estimates that if the E.U., China, and the U.S. all implement policies that succeed in reaching 100% zero emissions for new cars by 2035, then EVs would hit a global tipping point five years earlier than they would have otherwise.
In a similar vein, recent commitments by China, Japan and South Korea to end the financing of overseas new coal plants is a big step towards raising the cost of coal development globally, Sharpe says. These Asian nations have long been top funders of new coal plants being built around the world.
This is how tipping points could provide a new basis for international climate policy. For years, the UN’s climate meetings have focused on reaching a consensus around economy-wide emissions targets. But it might be more effective to break things up into sectors, identify the countries with the greatest capacity and willingness to make a difference in that sector and figure out how to unlock tipping points in each one.
“If you want to be successful in addressing the climate problem, you need to focus on these early movers that create the tipping points,” Victor says. “That’s a very different strategy from working on everything everywhere, all around the globe, all at once.”
That idea is at the heart of the Breakthrough Agenda, an initiative Sharpe helped spearhead at the COP26 meeting in 2021 when he was deputy director of the UK government’s COP26 team.
At that meeting, 45 countries committed to making green technologies the most attractive option in each high-emitting sector, from agriculture to steelmaking, by 2030. At this year’s meeting, COP28, Sharpe says, “the thing to watch … is what new actions countries have agreed to take together to speed up this change in the global economy.”
Based on these developments, “it encourages me hugely that countries are actually sitting down together, talking about the state of international cooperation in each sector and having intelligent discussions about what they need to be doing together,” says Sharpe. “Because I think that’s been hugely absent.”
A Roadmap For Positive Tipping Points
Most of the evidence for tipping points comes from car transportation and renewable power generation, which make up 9% and 26% of global emissions, respectively. Decarbonizing the world would require finding tipping points elsewhere, too. The Breakthrough Effect report, a document co-published by the sustainability advisory company Systemiq at the World Economic Forum in January, provides a rough roadmap for this. For instance, its authors — which include Lenton’s team and Sharpe — believe that a tipping point could unfold in the livestock farming sector, which is responsible for around 13% of global emissions. That could happen if climate-friendlier alternatives to animal protein — made from plants, microorganisms or simply lab-grown meats — become more attractive than meat in terms of accessibility, cost, texture and nutritional value.
Similarly, price declines could push electricity-driven heat pumps to replace gas boilers as building heat sources, a sector that accounts for 6% of emissions. Green hydrogen could help decarbonize multiple sectors by powering trucks and buses, by making fuels for ships and planes, by replacing coal in steel production and by providing a greener method for making the ammonia that’s used in agricultural fertilizers.
There may even be a tipping point for protecting carbon-hoarding ecosystems like forests, peatlands and coastal wetlands — damage to which currently accounts for an additional 10% of emissions — when the value of preserving them exceeds the value of destroying them for development.
As with renewables and EVs, progress made in any of these sectors would spread. A shift toward climate-friendly ammonia to make fertilizers, for instance, could accelerate the growth of the hydrogen industry to fuel ships and make steel. Greater adoption of plant-based proteins will not only lower agricultural emissions but also ease the demand for land, which will make it easier to protect natural areas.
In this way, strong policies in specific sectors — mandating zero-emissions vehicles, requiring green ammonia for fertilizer production and introducing alternative proteins into public institutions like schools and hospitals — could have a much wider impact beyond those individual sectors. Activating these three “super-leverage points,” according to the report, “could trigger a cascade of tipping points for zero-carbon solutions” in various sectors that collectively represent 70% of global greenhouse gas emissions.
The report leaves many open questions and uncertainties. It makes little mention of how to rapidly decarbonize concrete-making, a sector that generates a whopping 8% of global carbon emissions. When it comes to building heating, it acknowledges that while heat pumps are predicted to come down in price, it may not be enough to make the costs of installing them — which often involves retrofitting buildings — cheap enough. This means heat pumps will require a particularly large boost from governments.
Zero-carbon steel will also remain costly for a while, as it requires extensive retrofitting of existing factories or the building of new ones, making it therefore reliant on early investment and public procurement to create initial markets and build momentum, Sharpe says. The success of alternative proteins, the report adds, depends not just on their material advantages over meat, but on changes in cultural norms and values around eating animals. Protecting natural habitats, meanwhile, may simply have to rely on stricter regulation for the time being.
No sector will be smooth sailing, says Sharpe, who envisions each green technological sector as a boulder being pushed up a hill — it is propelled by research and development; helped along by investment, public procurement, subsidies or regulation; before it nears the top, the tipping point, when it finally gets whatever policy push needed to finally outcompete incumbent technologies. But, Sharpe cautions, “even as you go down the other side, there might be some bumps that you have to overcome.”
And “not all sectors have the same potential for tipping points,” says Alice Wu, a science policy expert of the Federation of American Scientists (FAS). Some sectors, like food and agriculture, may benefit from other solutions, like getting people to eat less meat to begin with, Gerber says. As the report itself acknowledges, more research is needed to proactively identify further tipping points, forecast them and find the most effective policies to unlock them. Last year, Lenton’s team, Systemiq and the climate initiative Systems Change Lab received a $1.2 million grant from the Bezos Earth Fund to do just this.
Though the jury’s still out on the overall impact on climate goals that positive tipping points could have, Lenton believes that they can give us the best chance of staving off dangerous levels of climate change.
Many experts fear that the worldwide goal of limiting global warming to 1.5 degrees Celsius above pre-industrial temperatures may be slipping out of reach. We are already at least 1.2 degrees over, and our current trajectory of planet-warming greenhouse gas emissions is on track to take us to 2.7 degrees this century. Although there remains some uncertainty around the precise thresholds of warming at which the bad climate tipping points will occur — and what their overall impact will be — many scientists agree that we’re getting dangerously close to triggering at least some of them.
Lenton estimates that we need to slash carbon emissions at least five times faster than current efforts — aiming to get to net zero by around 2050 — to secure a decent chance at avoiding them. “I’d say a majority of the sectors have evidence for positive tipping points,” Lenton says. He speculates that if we manage to unlock tipping points in energy, transportation and food and agriculture, we might be able to shave off a degree from our current trajectory, in a best-case scenario. That could stall warming somewhere around 1.7 degrees Celsius. Even then, there would be a risk of passing some tipping points, but we’d still avoid the massive levels of damage we would see at 2.7 degrees Celsius.
For Mark Paul, a political economist at Rutgers University in New Jersey, the notion of positive tipping points is already at the heart of the IRA. In addition to the IRA’s incentives for renewable energy and electric vehicles, the act also includes tax credits for green hydrogen plants and heat pumps as part of a plan to provide an overall boost to green technologies — a marked shift in policy given the U.S. government’s lengthy reluctance to be perceived as picking winners and losers, Wu notes.
Though Paul says he supports both carrots and sticks in policymaking, he praises the act’s carrot-driven approach, which he thinks, as an initial measure, is less likely to generate a public backlash than regulations like the Breakthrough Effect report’s suggestions to mandate the use of green fertilizers or zero-emissions vehicles.
Yet for all the proven, real-world success the IRA has achieved, it still faces significant challenges — the most important being its long-term credibility. A tipping point approach will only be successful if everyone has confidence that political support for green technologies will continue and not risk massive shifts every election cycle, Victor notes.
Overall, Paul isn’t confident that the U.S. government’s investments so far are enough to reach the tipping points needed to accelerate the green transition at the pace we need. “What I would caution is that this requires well-intended and well-executed government policy, and political processes are messy. We almost never end up with first-best policies,” he says.
It’s also worth remembering that some parts of the world face greater challenges than others when it comes to executing tipping points. The enormous cost declines in renewable technologies haven’t “really been of benefit to African countries,” says Grace Mbungu, who heads the climate change program at the Berlin-based Africa Policy Research Institute. There’s an urgent need for better — and more — funding opportunities as well as access to capital for renewable projects in African countries.
Even though Africa represents a fifth of the world’s population — a proportion that is set to grow over the coming decades — and has massive potential for technologies like solar, only around 2% of global investment in renewable energy goes to African countries. The financing costs for building renewable plants in Africa are at least twice to three times more expensive than it is in developed economies, chiefly because loans are more costly there due to a mix of real and perceived risks over future returns on investments, Mbungu says.
And while many African countries, like Kenya, have seen headway around electric vehicles — from the introduction of electric buses in cities like Nairobi to the manufacturing of electric motorbikes — access to affordable power remains a challenge. Many rural populations aren’t connected to reliable sources of electricity, let alone EV chargers. Charging might also risk straining existing overworked grids. And in countries like Kenya, where most of its electricity comes from renewable sources, energy is extremely expensive. “I think you need the right conditions to be able to take advantage of positive [tipping points],” Mbungu says. She believes that before moving to EVs, society needs to go through a total financial, technological, economic, social and industrial transformation.
Tackling Social Issues
There is another concern with EVs and renewables. Lithium-ion batteries are made with metals like lithium and cobalt, which are often extracted in the global South. Lithium extraction has played a role in draining groundwater supplies in Chile and cobalt mining in the Democratic Republic of the Congo has been associated with human rights abuses; both are tied to environmental degradation. With battery demand set to rapidly grow many times over, there’s growing concern around exacerbating these calamities in regions that are already bearing the brunt of climate change impacts.
Along with the deep social impacts of colonialism, which extracted vast resources from the global South, mining efforts are reinforcing a long-held sentiment that developing countries are being used to maintain wealth in the global North, says Laura Pereira, a sustainability transformations expert at the University of the Witwatersrand in Johannesburg, South Africa. “Transformations are hard, they’re messy,” she says. “But there are definitely … parts of the world that can afford to lose and parts of the world that just really can’t afford to lose anymore.”
Many solutions have been suggested to ease the impact of mining on affected countries. Perhaps most controversial is the idea of extracting cobalt and other critical minerals from the seafloor, another vulnerable ecosystem that researchers also know relatively little about. Then there’s developing more sustainable mining operations on land, along with traceable, robust supply chains. The latter is important, Pereira says. But although more mining will likely be needed for the green transition, it shouldn’t be the only solution; the global North must also do the much harder work of reducing its use of resources. Building recycling infrastructure for batteries, for instance, could significantly reduce the demand for these metals. Pereira would also like to see deeper, societal shifts in Western countries that result in less consumption overall; for instance, by prioritizing public transportation over private vehicle ownership.
Gerber worries that by focusing on a one-to-one replacement for fossil fuel-based technologies, reports like the Breakthrough Effect may distract from such deeper shifts, like building walkable cities where there’s less of a need for cars or expanding train networks. “If you can make those transitions in how society develops at the same time as you switch to renewables, that can lead to the best outcomes of all,” he says.
Other scientists have more fundamental concerns about the very concept of economic tipping points, worrying that they often oversimplify what technological progress looks like. After all, technological change isn’t solely determined by numbers and cost curves, but also by human agency — how consumers, companies, investors and policymakers approach and decide on whether to support new technologies, Geels says. In comparison to some natural systems, like lakes where tipping points between algae-dominated and clear states can occur in a predictable manner, socioeconomic systems are confounded by the complexity of human society.
Experts agree that the social element is critical to achieving a rapid green transition. For instance, the fate of many green technologies depends a lot on the consumers who, through their choices, create and shape markets.
Sociologists believe these kinds of effects spread via a contagion-like manner where people experience social pressure to behave like their peers. One well-known experiment found that if only 25% of people in a group decided to behave in a particular way — in this case, agreeing on how to label a picture — this would trigger a tipping point where the whole group would follow suit.
In line with such research, scientists have proposed a number of social tipping points that could spur more progress on climate change. For instance, one 2020 study by sociologist Ilona Otto of the University of Graz in Austria and her colleagues describes a tipping point that could lead to greater divestment in fossil fuels; some models suggest that just 9% of fossil fuel-supporting investors doing so could be enough to tip the system.
Similarly, greater transparency around how fossil fuel-related products are linked to human health harms through product labeling like what’s on cigarette packets, could help trigger a tipping point that leads to fewer people purchasing these products, Otto says. Another study, published in Science and co-authored by Srivastav, discusses political mobilization as a key tipping point to accelerate the green transition. Indeed, there are some signs of social change today, like growing public protests around climate change and people following their neighbors in installing solar panels on their roofs.
But in Geels’ view, much of the research on social tipping points involves a lot of wishful thinking; although history tells us that social changes can be powerful, he doubts that they’re as reliable in how they occur as some scientists hope. Social change doesn’t always stay on track; it requires maintenance. After all, human behavior is not static and people can change their minds after a tipping point occurs; some may never change their habits, especially when it comes to politically polarizing issues. Ultimately, social tipping points won’t happen by themselves. “In a way, it’s up to everyone, up to us, when those tipping points will occur and whether they will be fast enough,” Otto says.
And unlike natural systems, human society is full of institutions and bureaucratic processes that are intentionally designed to resist change. Those include vested interests in the political system, the lobbying by fossil fuel companies to obstruct climate policy or disinformation campaigns aimed at swaying public opinion on climate change.
For instance, even though global investment in clean energy is now substantially outpacing investment into fossil fuels, many energy companies are continuing to budget vast sums of money annually into updating and expanding existing fossil fuel infrastructure to maintain their business models even though renewables are cheaper, Paul says. And that may be the case, he says, “until we regulate them to a degree where they cannot [do so] or until we pass a carbon price to a degree where it is just woefully uncompetitive.”
Some researchers worry that scientists, hoping to find reasons to believe that there is a fast way out of the climate crisis, may be using the tipping points concept too loosely, identifying ones without sufficient evidence; strictly speaking, tipping points must rapidly drive a system to substantially shift into a different state through self-reinforcing processes, like the Greenland glacier, and must be hard, if not impossible to reverse.
Calling processes tipping points when they don’t strictly meet those criteria may create the misleading impression that there are quick fixes to climate change. “We don’t want to promise solutions that work rapidly and therefore draw attention away from solutions that take more time but need to be enacted right now,” says Manjana Milkoreit, an expert in Earth system governance and international politics at the University of Oslo.
An Uncertain Future
Lenton agrees there is some wishful thinking among scientists, but he thinks there is compelling evidence for imminent tipping points in the sectors he’s studied. In fact, he’s currently working on finding further evidence. Scientists know from studying natural systems that right before they cross a point of no return, these systems begin to lose resilience; taking increasingly longer to recover from disruptions, for example, in fish populations affected by disease. This loss of resilience can be mathematically quantified.
Such “early warning signals” have been spotted in some climate systems today, from the Jakobshavn Glacier to an important circulation of ocean currents in the Atlantic, as well as, curiously, in ancient human societies before their collapse. Lenton says he’s already found tantalizing hints of such signals in global data around combustion engine vehicles, which could suggest their imminent decline. Finding such signals may not only strengthen the evidence for an EV transition, but the approach might also provide a way of identifying imminent tipping points in other sectors. “Then you could use that information to target your policies to give that last little push,” says Marten Scheffer, a complex systems theorist at Wageningen University and Research in the Netherlands.
There are other signs that change is on the horizon. Several major carmakers, including General Motors, Mercedes-Benz and Ford, have pledged to phase out sales of gasoline and diesel vehicles by 2040 globally. A study published in April predicted that of the nearly 500 gigawatts of new coal plants scheduled for construction this year, around half would be canceled. The number of patents relating to fossil fuel-based technologies has also declined by almost 20% since 2015. Perhaps the ramp-up of political efforts by fossil fuel companies to slow the green transition is in and of itself a sign that change is imminent, the Breakthrough Effect report suggests.
It is telling that these changes give Lenton hope, given his deep understanding of the consequences of us failing to decarbonize the world in time. Critical ocean circulations in the Atlantic might collapse, disrupting monsoons in other parts of the world, and affecting hundreds of millions of lives. The tipping of major ice sheets could unleash many meters of sea level rise hundreds of years into the future and swamp cities like Shanghai, Lagos and London. “We’re at real risk of tipping irreversible changes, even if they unfold what feels like slowly for us, in a way that could cause profound harm to future generations,” Lenton says.
Granted, change will be messy and complicated, fraught with unforeseen challenges and will require policymakers to think deeply about how a green transition can be achieved equitably. But by concentrating our collective efforts on the seemingly Sisyphean task of pushing the boulder over the hill, perhaps positive changes will beget more positive ones, helping us avoid the apocalyptic visions that seem to litter our every day and tipping us into a better tomorrow.
