The Scottish Government plans to set a new and more testing climate-change target for 2020 after exceeding the existing benchmark six years early.

Figures published on Tuesday show a 45.8% reduction in greenhouse gas emissions was achieved by 2014.

The government had set a goal of reducing emissions by at least 42% by 2020, and 80% by 2050.

The statistics also revealed Scotland met its annual target for the first time in 2014.

Climate Change Secretary Roseanna Cunningham told Holyrood that Scotland was making "outstanding progress" in reducing emissions.

Political opponents and environmental campaigners said loss of heavy industry, milder winters and a changing share of European emissions credits contributed more to the cut than bold government policy.

Cunningham told MSPs the new 2020 target would be "realistic and achievable", and based on expert advice.

She said: "I can advise the chamber that I am writing to the Committee on Climate Change today, seeking their advice on Scotland's future targets in response to the Paris Agreement.

"These ambitious new targets will serve as a statutory impetus to further action.

"Delivery will require co-ordinated approaches across portfolios and the reflection of climate-change considerations at the very highest level of government."

She added: "We set ourselves a high bar and are showing by our deeds, as well as our words, that Scotland can indeed lead the world.

"Our progress provides a strong platform upon which to build."

Conservative MSP Maurice Golden said: "Although I welcome that the targets have been met after four years of missed targets, I am dismayed that, overall, this is a result of accounting changes rather than attributable to actions of the Scottish Government."

Mark Ruskell, the Scottish Greens' climate change spokesman, said: "It is clear that quirks in accounting, warm weather, wind farms and recycling have finally resulted in a met target.

"It is hard to see how Scottish Government policy has delivered much of this progress and we still have much to do on transport and housing."

Labour's Claudia Beamish welcomed the progress but said there needed to be "a significant strengthening of policies".

Stop Climate Chaos Scotland welcomed the figures but added it was hard to see the "bold fingerprint" of government policy driving the progress.

Jim Densham, of the group, said: "This shows it's possible to cut emissions while building a progressive and productive society.

"However, apart from the electricity and waste sectors, it's hard to see a bold fingerprint of Scottish Government policy driving the transition to a zero-carbon economy."