Electric vehicle sales in China and Europe have reached a threshold or 'tipping point' that has triggered an irreversible shift away from their petrol and diesel-powered equivalents.
Researchers analysed global sales from 2016-23 and observed that EV sales were increasing exponentially across 32 countries, with the global fleet of electric and hybrid vehicles doubling every 1.5 years.
Most sales were in the lead markets of the EU, China and US, where sales have doubled every 1.3, 1.0 and 1.7 years respectively.
In contrast, sales of traditional cars began to decline steadily from around 2019, compounded by the COVID19 pandemic.
But as economies recovered after the pandemic, these sales continued to slide while EV and PHEV sales remained buoyant.
The rapid growth in EV market share alongside sharp declines in combustion car sales and signs of weakening market resilience for fossil-fueled vehicles are among the key signs of a positive tipping point, the researchers say.
Another sign was the growing variety of electric vehicles on the market, combined with a decline in the variety of traditional vehicles.
A further indicator was price parity, with advanced modelling tools predicting that on the current policy trajectory this will occur in Europe and China between 2025 and 2028, followed by the US, Canada and South Korea between 2026 and 2030 and the rest of the world between 2030 and 2035.
They identified these critical indicators by analysing the volatility of market shares of conventional vehicles over the years before the COVID pandemic and observing fluctuations becoming more intense while slowing down at the same time.
The researchers say this is a classic signature of the onset of a tipping point, often observed in climatological data.
Professor Tim Lenton from the University of Exeter said: "We show for the first time in market data, early opportunity signals before a positive tipping point where uptake of EVs (and decline of fossil-fuelled cars) becomes self-propelling. For markets that haven't tipped yet, governments and investors can use this signal to indicate where policy efforts and investment can have the biggest bang for their buck. For manufacturers it provides a strong steer to shift their investment and production lines from fossil fuelled cars to EVs, or risk getting left behind."
But although EV uptake in China and Europe has now become self-propelling, it was found not to be rapid enough for existing climate objectives, which require the elimination of transport emissions by 2050 in Europe and 2060 in China.
The researchers say intensifying policy action in these leading markets can accelerate the tipping point to achieve their climate objectives and would help reduce the cost of EVs in the rest of the world, allowing other countries to get on board the EV transition sooner.
Jean-Francois Mercure, Director of Exeter Climate Policy, said: "Technological change can happen suddenly and abruptly. For EVs, it is the result of lots of policy-making efforts over the 2000s-2010s, leading to building up a critical mass, and a tipping point unfolding now, which would be quite hard to reverse.
"Experience shows it was neither just subsidies on EVs nor regulations on their own that achieved building a critical mass in Europe and China, it was combinations of both. Subsidies make EVs affordable, while public procurement and EV mandates (requiring manufacturers to sell a proportion of EVs) increase the availability of EVs, enabling the subsidies to be effective, while carbon taxes played little role, if any.
"Policymakers therefore need to intensify, or at least maintain, those policies in China and Europe to ensure that cost reductions continue, allowing peripheral markets such as in South-East Asia, Africa and Latin America to get on board this moving train as soon as possible."
The study also identifies significant and varied economic benefits of reducing oil consumption in oil importing countries, which include less pollution and related diseases and greater international purchasing power via the balance of trade, which could be used for other development objectives.
Professor Mercure added: "A rapid decline in combustion engines in vehicles has huge implications for global oil markets and oil producers, as it almost certainly implies peak demand for oil in the current technological trajectory before 2030 or soon after. This can have positive or negative ramifications for different countries depending on their economic structure, but particularly benefits oil-importing developing countries as it frees up international purchasing power. It could, however, push oil producing developing economies into fiscal or financial difficulties."
