Short-haul flights across Europe could be replaced by high-speed rail under ambitious European Union proposals to reduce carbon dioxide emissions from transport by 60% over the next 40 years.

According to the EU, Heathrow's congestion problems could be eased by cutting domestic and European flights, while demand for new runways could be suppressed by building new rail networks. The EU transport commissioner, Siim Kallas, has announced a series of green transport goals including phasing out the use of petrol cars in city centres by 2050.

"At Heathrow there are no new runways, but we desperately need to increase capacity and you can do this if you reduce short-haul flight connections," said Kallas. The commissioner added in an interview with the Guardian that the UK should look at the example of Spain, where high-speed rail has hit demand on a previously popular flight corridor.

"This has happened in Madrid and Barcelona, where 50% of the market has moved to high-speed rail. It is comfortable for everybody. Airlines can put emphasis on long-haul flights, which is better for their business."

Noting the debate over expanding London's squeezed airports, he added: "If we are successful in creating new railways they can take over short-haul airline connections. It makes it easier for the runway issue."

Kallas hit the headlines this month when he declared a target of phasing out petrol and diesel cars from city centres by 2050. The commissioner said he was unfazed by criticism of the benchmark. "If you don't like the idea of reducing the use of conventional cars in city centres, what are your proposals?"

Kallas said EU countries needed to reduce the "mass need" for short journeys in petrol and diesel cars. "It is a desirable goal to phase out conventional cars," he said. However, Kallas added that mass adoption of electronic cars also posed problems because major city roads would continue to be clogged by traffic.

Speaking after a meeting with officials at Transport for London, Kallas said: "The congestion charge is a step that many cities [in Europe] will follow." Kallas's 2050 targets include connecting all hub airports to high-speed rail lines and connecting majors ports to rail networks in order to reduce dependency on road freight.