An “aggressive” expansion of railways—with well-engineered policies in the conductor’s seat—could see global transport emissions peak in the 2030s, according to a new report from the International Energy Agency (IEA).
In a detailed overview of the report, Carbon Brief highlighted the IEA’s assessment that rail is “uniquely positioned” for the rise of renewables because it is already significantly electrified. The mode is also hugely efficient, using “just 2% of the world’s transport energy demand” to move 8% of the world’s passengers and 7% of its freight.
While rail is already comparatively low-emission, contributing approximately 0.3% of global CO2 emissions annually compared to about 2% for aviation, IEA recommendations to achieve “zero-emission mobility” include the need to factor in not only power supplies but also “emissions from railway construction and maintenance,” Carbon Brief notes. A key factor in that assessment is that “railway lines—in particular those with numerous tunnels, viaducts, and bridges—use large amounts of concrete and steel.”
The IEA report also flagged key regional differences, noting that low occupancy rates render trains less energy efficient in the United States and even the European Union than in Asia. Another point of divergence is track electrification, which exceeds 60% in both Europe and Asia but falls below 5% in North and South America.
The agency reports rapid expansion over the last few years in the high-speed rail infrastructure that will be needed to replace emissions-dense short-haul flights: “Worldwide, around 600 billion passenger kilometres were travelled by high-speed rail in 2016, compared to around 100 billion passenger kilometres in 2000,” Carbon Brief states.
Where much more work remains to be done is in rail freight, the IEA concluded. While “freight has risen steadily over the past 20 years and continues to expand in most countries,” truck use is “expanding faster,” even though “rail uses around 90% less energy than trucks per unit of freight.”
The IEA report contains two scenarios for rail expansion through mid-century. The base scenario assumes no significant increase in the emphasis rail receives from policy-makers. It shows annual investment increasing to $330 billion in 2050, metro and high-speed rail networks expanding 2.5-fold, and global transport emissions increasing through mid-century and beyond.
In the high-rail scenario, by contrast, average annual investment hits $770 billion by 2050, high-speed and metro track networks grow three- and four-fold respectively, and “global passenger activity on rail is 60% higher than in the base scenario.”
But Carbon Brief says that outcome will depend on policies that “minimize the costs of rail travel by ensuring maximum rail network usage and working to remove technical barriers,” maximize revenues (including capital increases in the value of homes and businesses thanks to rail expansion), and ensure “that all forms of transport pays for their societal and environmental impacts, such as through fuel taxes and congestion charges.”
The payoff, IEA says, is that the right combination of policies can “lead to greenhouse gases from global transport being 0.6 GtCO2e per year lower than in the base scenario, roughly the annual emissions of South Korea.”