The Whitehall department and its subsidiaries tasked with fighting climate change spent more than £300,000 flying civil servants and ministers around the UK last year, new figures have found.
Ed Davey's Department for Energy and Climate Change spent £148,000 on 668 internal flights, while public bodies attached to it cost the taxpayer another £163,000 on more than 1,000 domestic flights.
The new figures were criticised by Green MP Caroline Lucas, who said she found it hard to believe civil servants and ministers could not have taken more eco-friendly trains on some of the journeys.
A breakdown of the flights showed that most covered trips of more than 400 miles between London and Scotland. But there were other shorter journeys, including flights between Aberdeen and Wick Airport in the far north of Scotland, which are only 200 miles apart by road.
Meanwhile, the Department for Environment, Food and Rural Affairs - run by the often-regarded climate-change sceptic Owen Paterson - spent far less on domestic flights. The Conservative Environment Secretary and his officials took only 219 domestic flights last year at a cost of £37,445.
The figures, which were revealed in answers to written parliamentary questions, showed the Government spent more than £1.7 million on almost 15,000 domestic flights in 2012-13.
The Home Office spent the most money. The department itself spent £700,012 on 7,200 flights, while the College of Policing cost the taxpayer £56,636 on 571 trips by air. The Disclosure and Barring Service, also attached to the Home Office, spent £7,704 on 90 flights.
A number of departments have yet to release their figures, while the Department for Work and Pensions and the Department for Transport both said it would be too costly to provide details.
Labour MP Michael Dugher (Barnsley East), shadow minister for the Cabinet Office, who tabled the written parliamentary question, said: "Over the last year, as people across the country have been facing a cost of living crisis, ministers and staff at Government departments have spent an astonishing £1.7 million jet-setting around the UK. With modern communications, how can all these flights be necessary?
"It's also ironic that the Department for Climate Change is one of the worst offenders, with ministers and staff taking more than 1,500 domestic flights at a cost of over £300,000 in the last year alone. So much for setting a good example on keeping the Government's carbon footprint down."
Ms Lucas said she thought trains could have been easily used by officials and ministers instead to reduce the impact on the environment.
She said: "I find it hard to believe that trains weren't an option on at least some of these routes. Given the impact of carbon emissions from aviation, it's disappointing that the department isn't showing more leadership."