Aberdeenshire Council has reduced its carbon emissions by 21% in the past seven years, figures have revealed.
The local authority says it is also now on target to reduce emissions from its buildings by 35% by the end of 2018/19.
But councillors will be advised later this week that the estimated cost for the council's buildings to become carbon neutral is over £90million which, given current financial challenges, "is not affordable".
Since an emissions baseline was established in 2010/11 when council carbon dioxide emissions totalled 86,154 tonnes, departments have made significant reductions in all sectors with the exception of fuel use at depots.
Aberdeenshire Council has an agreed target to reduce carbon emissions by 44% by 2025, according to the Local Democracy Reporting Service.
A report being brought before the authority's Sustainability Committee reveals that emissions from operational buildings have reduced by 26%, street lighting is down by 37%, fleet by 4% and business miles by 31%.
Director of business services Ritchie Johnson says the reductions have been supported by both a reduction in consumption and changes to emission factors produced annually by the UK Government Department for Business, Energy & Industrial Strategy.
He says: "The emissions factors are anticipated to continue to reduce as the national grid becomes further decarbonised, due in the main to UK Government incentives for suppliers to increase the use of renewable energy generation across the UK.
"If the expected reduction in carbon emission factors continues, the council’s emissions from buildings targets will be met by 2025."
Despite warning about the prohibitive cost of becoming carbon neutral, Mr Johnson says the reduction in emission factors will enable the council to achieve the 44% reduction in emissions from buildings by 2025 and with a significantly reduced need for expenditure.
Among the council's low-cost energy-efficiency projects was the upgrading of internal and external lighting to LEDs, improved heating controls and insulation measures which would typically pay back in less than a decade.
Mr Johnson states: "The first tranche of proposed projects is expected to realise energy savings of 3,500,000 kWh per year and CO2 savings of 1,500 tonnes (3% per year), once fully implemented."