The die is cast: petrol and diesel engines are dying. The electric age is inevitable

Arguments over the green credentials of electric cars are already over. Work on 21st-century tech, and leave the past behind

It should by now be clear to all vehicle manufacturers and policymakers that the electric vehicle (EV) age is all but inevitable. Most drivers already get it, as shown by the huge order books for most electric models. The long-running fight over whether electric or petrol/diesel engines generate more emissions during their lifecycle, further fuelled by Rowan Atkinson's recent intervention, is in fact all but over. After years of crunching the numbers, peer-reviewed studies consistently arrive at the same conclusion: EVs win. The UK government's own research supports this position and concludes that transitioning to zero-emission vehicles would "significantly" reduce overall carbon use.

Of course, where the vehicle and battery are manufactured, and how the electricity is generated, make a difference to the carbon benefits of EVs. But helpful and accessible tools such as the Transport & Environment campaign's How clean are electric cars? calculator are doing much to demystify these concerns for the average person. This tool clearly shows that across its whole lifetime, a small EV driven in Sweden using a battery produced there emits 83% less than a similar petrol car – that's a huge improvement. Even one driven in Poland with a battery made in China still emits 37% less.

As someone who has spent more than 20 years working in e-mobility, first in policy and then in the EV industry, I want to see us move beyond the basic emissions debate – which by any reasonable standard of proof is over. With EVs already numbering more than 20 million worldwide, and global EV sales surging every year, there's so much more to discuss about EV technology that is of supreme importance to how we approach climate policy.

First is the under-appreciated efficiency improvements offered by EVs. Since the start of the industrial revolution, the heat engine has been the core technology enabling the controlled release of the significant quantity of energy contained in fossil fuels. In the 300 years between the invention of the first steam engine and the kind of internal combustion engines (ICE) used by most vehicles today, thermal efficiencies – the amount of heat converted into work or motion – have dramatically improved, from less than 1% for the Newcomen engine (invented in the early 18th century and used to pump water out of deep mines) to around 40% for the Toyota Prius hybrid.

However, since the French physicist Sadi Carnot first expounded the thermodynamic cycle in 1824, we have known that the maximum efficiency of any heat engine is limited by the upper and lower temperatures of an engine's cycle. Carnot's formula tells us that we have already reached this limit for petrol engines; any further investment only providing diminishing returns. The petrol engine is therefore doomed to waste at least half the energy carried in a car's fuel tank.

EVs, on the other hand, convert the electrochemical energy stored in the battery to motion using motors that have efficiencies of more than 85%, and even accounting for the losses of delivering energy to the charger, EVs remain more energy- and carbon-efficient than their fossil-fuel equivalents. And electrification gives us a clear path to the greater use of renewables as the grid continues to decarbonise. In an age when energy is a highly valued resource, and there is an urgent need to drastically cut carbon emissions, we must therefore be bold and ditch the heat engine as fast as possible.

Second is the observation that the automotive industry is increasingly at odds with the other technology sectors, and closer to the age of steam than one based on modern materials and processes. While the digital revolution is transforming almost all human experiences, ICE-powered road transport continues to rely on largely mechanical systems that use steel components, with each vehicle having tens of thousands of moving parts, all of which must be designed, supplied and maintained. Furthermore, the vehicle's energy is provided by complex, processed liquid fuels that are transported in bulk from halfway around the world. This makes it highly dependent on heavy engineering and the movement of large quantities of raw and processed materials.

Contrast this with the possibilities offered by electrification – ones that are already materialising at scale. Vehicles that are high-quality, high-performance, zero-emission and quiet in their operation, with driving ranges of more than 300 miles, recharging times of less than 30 minutes and batteries that can be recycled. Vehicles that are relatively simple in their engineering design, constructed from lightweight materials such as carbon composites, and controlled by highly flexible software that can be updated over-the-air. Not only can EVs be charged using renewable energy, they can also provide mass storage for excess wind and solar energy at times of oversupply, and then support the grid by feeding back this energy at peak times, becoming a critical part of our future energy infrastructure.

Yes, we need new battery chemistries to extend vehicle ranges at lower costs. Yes, we need more public charging infrastructure (the UK's target is for 300,000 devices by 2030). Yes, we must be vigilant to ensure that the new environmental impacts of mining and battery production are well understood and highly regulated. And no, EVs on their own are not enough to solve the transport element of the climate crisis – we also need better public transport and more support for walking, cycling and new mobility services.

But to press on with a 19th-century technology makes no sense in the digital age, which is decarbonising at pace. While completing the transition from internal combustion engine to EV will be challenging and will require imagination, innovation and investment, not doing so would be a grave mistake. It would cost not just carbon emissions and cleaner air, but also jobs and the UK's place at the global automotive table.

Ben Lane is co-founder and CTO at Zapmap, a UK-wide map of electric car charging points