A city council is set to miss its 2025 carbon neutral target because it is still burning too much gas.
Bristol City Council, which declared a "climate emergency" four years ago, is forecast to emit almost 1,700 tonnes of carbon in 2028.
A cabinet report says it is because many buildings on the council's estate are still burning large amounts of gas.
Councillors have now signed off on plans to renew the authority's gas supply contract for another four years.
While progress is being made on reducing carbon emissions the latest figures show there is still a long way to go, according to the Local Democracy Reporting Service.
Despite reducing its demand for gas, the council is forecast to miss a crucial target of becoming carbon neutral on its own estate by 2025.
Burning gas, in places like City Hall and crematoriums, is expected to emit 2,212 tonnes of carbon dioxide in the financial year 2025/26, dropping to 1,693 tonnes by 2027/28.
Its demand for gas is expected to fall as its buildings are gradually connected to the expanding district heat network; boilers are replaced with heat pumps or electric boilers and some buildings are sold off.
These measures could reduce the council's overall gas use by more than a fifth.
'The toughest phase'
The cabinet report said: "The energy market is stabilising, albeit at twice historic rates, but it remains difficult to forecast future energy costs to any degree of certainty...Prices have been estimated conservatively based on current and recent rates."
Over a four-year contract, this would mean the amount the council spends on gas falling from £23 million to £19 million. This includes the council spending an extra premium of £546,000 on "green gas", which is allegedly better for the climate than normal natural gas.
Writing on the mayor's blog, Labour Councillor Kye Dudd, cabinet member for climate, said the council's direct emissions of greenhouse gases had halved over the past eight years.
But he added that the programme to get to carbon neutral was now in the "toughest phase."
"We're now into the phase of the programme that we always knew would be the toughest to deliver and have taken the steps necessary, such as the formation of Bristol City Leap, to have the tools available to meet our target of being a carbon neutral council by the end of 2025," he said.