The Scottish Government should consider introducing congestion charging to help meet its climate change targets, according to a report.
The paper prepared by the independent Committee on Climate Change (CCC) said stronger policies are needed in areas such as transport, renewable heat, agriculture and forestry if targets are to be met in future.
It warned that plans to cut air passenger duty by 50% when it is devolved to Holyrood could lead to increased carbon emissions and called for a re-evaluation of speed limits.
The progress report for Scottish ministers confirmed that Scotland missed its target for emissions in 2012, the third time an annual target has not been met.
Net emissions in 2012 were 55.67 million metric tons of carbon dioxide equivalent (MtCO2e), compared to the target of 53.226.
The report found that Scotland performed better than the UK as a whole and made good progress in areas including renewable electricity generation capacity and installing community and locally-owned energy projects.
However, it highlighted that transport emissions accounted for 21% of Scotland’s total and said the Scottish Government should consider other options to drive the figure down.
“To encourage behaviour change, it may be necessary to explore other options such as congestion charging,” the report said.
“Congestion charging has been successful in reducing the amount of vehicles on the roads in two UK cities (London and Durham).”
The report added: “Speed limits are likely to be fully devolved to Scotland in the future.
“The Scottish Government should evaluate how speed limits (in particular greater enforcement) could help with meeting carbon targets.
“They are also likely to get control over air passenger duty and have suggested that the duty might be cut by 50%.
“This could lead to increased carbon emissions if it were to result in an increase in flight and passenger numbers.”
The CCC also found Scotland is not on track to meet its renewable heat target to source 11% of demand from renewable sources by 2020.
Among its recommendations are effective energy efficiency schemes for flats, which make up 38% of the Scottish housing stock, and “ambitious” CO2 reduction targets for government buildings.
CCC chief executive Matthew Bell said: “I have met with a large number of stakeholders in Scotland over recent months.
“Without exception they have commented positively on the ambition of the Scottish greenhouse gas reduction targets.
“That ambition means they are difficult to meet but also places Scotland among the leaders in the world.
“The Scottish Government and wider society will have to consider what additional measures to take over the coming years to continue to live up to that ambition.”
Stephanie Clark, policy manager at Scottish Renewables, said: “While Scotland has made tremendous progress in the development of renewable electricity it has, regrettably, made far less
progress on low-carbon heat.
“Heat accounts for 50% of Scotland’s carbon emissions, so in order to successfully tackle climate change we need to see increased public sector leadership in driving the expansion of low-carbon heat.”
Tom Ballantine, chair of the Stop Climate Chaos Scotland coalition, said: “This report today from the Government’s own advisers is the fourth time they have advised that the Scottish Government needs to do much more to meet legal requirements on greenhouse gas emissions and deliver the benefits of a low carbon economy.
“With the strongest call yet from their own advisers to do more to reduce emissions, it’s time for the Scottish Government to heed these repeated calls and take urgent action now to deliver on Scotland’s vitally important climate commitments.”
Climate change minister Aileen McLeod said: “I welcome this progress report from the Committee on Climate Change, which shows that Scotland is outperforming the UK as a whole in reducing greenhouse gases as a result of the innovative and effective action we are taking to achieve Scotland’s climate change targets, which are the most ambitious in the world.
“The report also emphasises the good progress that Scotland is making against our targets – particularly in relation to renewable energy – and recognises the challenges we are facing as a result of improvements in calculating estimated emissions.
“Although we have already made substantial progress, the Scottish Government is stepping up climate change action and we have put in place a comprehensive package of policies and measures to meet our emission reduction targets.”