Bullet trains are back on the political agenda. As the major parties look for ways to stimulate the economy after the COVID-19 crisis, Labor is again spruiking its vision of linking Melbourne, Sydney, Canberra and Brisbane with high-speed trains similar to the Eurostar, France’s TGV or Japan’s Shinkansen.

In 2013 when Labor was last in government, it released a detailed feasibility study of its plan. But a Grattan Institute report released today shows bullet trains are not a good idea for Australia. Among other shortcomings, we found an east coast bullet train would not be the climate saver many think it would be.

Anthony Albanese releasing a high-speed rail study in 2013. The idea has long been mooted. AAP/Lukas CochThe logic seems simple enoughBuilding a bullet train to put a dent in our greenhouse gas emissions has been long touted. The logic seems simple – we can take a lot of planes and their carbon pollution out of the sky if we give people another way to get between our largest cities in just a few hours or less.

And this is all quite true, as the chart below shows. We estimate a bullet train’s emissions per passenger-kilometre on a trip from Melbourne to Sydney would be about one-third of those of a plane. We calculated this using average fuel consumption estimates from 2018 for various types of transport, as well as the average emissions intensity of electricity generated in Australia in 2018.

If we use the projected emissions intensity of electricity in 2035 – the first year trains were expected to run under Labor’s original plan – the fraction drops to less than one-fifth of a plane’s emissions in 2018.

It should be remembered that while coaches might be the most climate-friendly way to travel long distances, they can’t compete with bullet trains or planes for speed.

Notes: Average occupancy estimates are 38.5 (coach), 320 (bullet train), 119 (conventional rail), 2.26 (car), and 151.96 (plane). Plane emissions include radiative forcing. For more detail, see 'Fast train fever: Why renovated rail might work but bullet trains won’t'.