A strategy to decarbonize the global transport sector by 2050, explained

Last year, ICCT published Vision 2050: A strategy for decarbonizing the transport sector by midcentury. It’s a concise paper, and we’ve just released a series of short videos that summarize six key elements of our strategy. The strategy and the videos are designed to explain to a general audience where transportation stands now with respect to climate and air pollution, where it needs to go, and how to get there. Vision 2050 contains a lot of hard numbers, and some hard truths.

Here’s the hardest and most important truth, one you may have heard before: We’re out of time. We have about 30 years to bring greenhouse gas emissions (GHG) to net zero if we want any chance of limiting global warming to 1.5 degrees Celsius. Greenhouse gas emissions—everything that enters the atmosphere and contributes to warming, from diesel soot to CO2 to methane—must be reduced now. This year. And they need to fall by about half by 2030.

In practice, that means not only reducing emissions from burning fossil fuels in cars and trucks, aircraft, and ships, but also controlling methane leaks from natural gas engines and only permitting biofuels from non-food-based feedstocks and energy crops. And, in practice, it means achieving these reductions while projected demand for freight and personal transportation more than doubles.

In 2019, we assessed what reductions could be possible globally in the transportation sector from technology efficiency improvements, vehicle electrification, deep decarbonization of the grid, and the use of low-carbon fuels.

Figure. Baseline CO2-equivalent emissions and mitigation potential in 2050 by major transportation segment. 

The right policies on efficiency, electrification, and fuels can get the transportation sector about 85% of the way to a 1.5*C target. Policies in other parts of the transportation sector—encouraging transit use or making walking and biking easier options in cities—can get us the rest of the way.

If we want to make genuine progress in decarbonizing the transport sector, we must focus on the following:

We must recognize that EVs are the single most important technology for decarbonizing the transport sector. [Video 2]

By our estimate, sales of electric vehicles (EVs) will need to reach up to 35% of the global market in 2030, with higher levels in major markets. As costs of EV batteries have declined by 90% over the last decade and are projected to drop by another half over the next decade, we estimate that the purchase price to consumers of battery-electric passenger cars will reach parity with conventional internal-combustion engine (ICE) vehicles in the next four to eight years. Eventually, they’ll be cheaper than conventional cars. Although current government electrification goals are headed in the right direction, they are not nearly ambitious enough to achieve the reductions needed in the transport sector. To incentivize the production and adoption of electric vehicles, we need to focus on policies including fiscal incentives, infrastructure investments, consumer information, and more stringent fleet-average reduction requirements.

We must continue to make progress on energy efficiency [Video 3]

Cumulative EV sales between now and 2050 could reach about 5 billion, but even in this best-case scenario, current projections indicate that the auto industry will build another 2 billion ICE vehicles during this time. The difference between building those 2 billion vehicles to current efficiency standards and building them to more stringent but still technically and economically feasible standards will be about 38 gigatons of carbon emitted into the atmosphere. By our estimates, this is roughly equivalent to an additional ten years of carbon emissions from the entire global transportation sector at 2050 levels. This is why vehicle fuel-efficiency standards, like the greenhouse gas regulations in the United States or Europe’s CO2 emission limits, are vital. They may seem like yesterday’s policy, but they’re not. They’re backed up by hefty enforcement provisions and are designed to allow automakers to roll out new vehicle models in sync with their product development cycles. In short, they work: they reduce carbon emissions, save consumers money at the gas station, and increasingly drive electric vehicles into the marketplace.

We must reduce black carbon emissions radically. [Video 4]

By our estimate, heavy-duty vehicles, including buses, are responsible for more than a third of the CO2 emissions in the transportation sector. We can’t meet the goal of reducing transportation emissions by 85% from 2020 levels by 2050 without them. With almost 425,000 electric buses currently on the road, we estimate that by 2050, e-buses can be four-fifths of the global bus stock. Outside of public transport, decarbonizing on-road freight transport is a different hurdle, and will likely require the use of fuel cells as well as electrification. We’re further away from the levels of infrastructure and technology development this demands, so we need to push aggressively on both ICE efficiency and the large-scale, coordinated policy interventions that can move us toward zero emissions in the heavy-duty truck segment.

We must continue to research and develop zero-emission technologies for the most challenging segments, such as international marine and aviation. [Video 5]

Among transportation sectors, shipping ranks the third highest in GHG emissions, behind light-duty and heavy-duty vehicles. To reach the International Maritime Organization target to reduce emissions from shipping in 2050 at least 50% below 2008 levels, we need a combination of strategies: improved operations, technology-based efficiency improvements—like hull air lubrication and wind-assisted propulsion—and zero-emissions technologies. Some of those technologies, like hydrogen fuel cells, are already well within reach. Our research has found that 99% of containership voyages in the busy North Pacific shipping corridor between the U.S. and China can be powered by hydrogen instead of fossil fuels, with only minor changes to ships’ fuel capacity or operations, such as adding a refueling stop along the way.

Like the marine sector, significant benefits can be obtained in aviation—the fourth largest emitter at 10%—through operational and technology-based efficiency improvements and zero-emission technologies. Sustainable biofuels, e-fuels, and hydrogen fuel cells are all plausible options that are undergoing research and development for future use.

The ICCT is committed to researching the most relevant and viable solutions needed to reach the 1.5°C goal. We know that we must steeply reduce greenhouse gas emissions by mid-century to avoid the catastrophic effects of additional warming. We also know that we’re out of time. But, as illustrated above, the solutions do exist. We just need to put in the work to get there.

There’s a lot more to say about this. In particular, cities are increasingly leading the way in promoting vehicle electrification to reduce emissions and address air quality. We’ll have more to say about that and Video 6 of our series in a subsequent blog.

See the entire playlist here.