Cutting the speed limit from 70mph to 60mph would make a “huge difference” in reducing carbon emissions, MSPs have been told.
The proposal is among a raft of recommendations made by the Committee on Climate Change (CCC) in its annual evaluation of the Scottish Government’s progress towards climate targets.
The committee praised Scotland for leading the UK in reducing greenhouse gas emissions but said fresh policies would be needed if ambitious new targets are to be met, particularly in relation to emissions from transport, housing and agriculture.
SNP ministers have committed to introducing a new Climate Change Act, with the aim of reducing emissions by more than 50 per cent by 2020.
The CCC said its analysis suggested that reducing the speed limit from 70mph to 60mph could cut car emissions by around 8 per cent on average, as driving at higher speeds can reduce fuel efficiency.
The report said that a model had been designed to estimate carbon savings from speed limit changes on trunk roads and motorways in Scotland.
“It has not been developed into a full appraisal but it is a tool that has been tested,” it said.
CCC chairman Lord Deben told Holyrood’s Environment Committee: “I don’t think it is for us to say, ‘you ought to cut the speed limit to 60mph’, but what we have to do is to remind people of the realities of having it at 70mph.
“We have to say, ‘if you don’t do this then if you want to meet the requirements you’ve got to do other things’, and you’ve got to decide which are the politically acceptable things.
“What you can’t say is that we we will do neither, and that’s the issue and that’s why it’s worth highlighting something which we know is politically very controversial, to say that would make a huge difference, so if you don’t do that where does that 8 per cent come from elsewhere?”
The Scottish Government has set out plans to cut air passenger duty by 50%, a policy criticised by environmental campaigners.
Lord Deben told the committee: “If you make a choice of that kind, you need to look and see what you have to do in other areas to balance that up, and it may well be that you say for social reasons that you want to do something which is more difficult as far as emissions are concerned but ... If you do that you have to say at the same time what the total effect is on your budgets for carbon and what you’re going to do to cover that off.”
He added: “Part of that political decision is never avoiding the fact that any decision costs something, so what does it cost and what do you intend to do to offset that cost?”
Commenting on whether he thought there was a place for fracking in relation to climate change as a transition fuel, he said: “We don’t have a philosophic opposition to fracking but we do have a very clear statement about what what you have to do to make sure that it would be within the budgets which we’ve laid out.”