Birmingham’s claim to be leading the way on delivering the green agenda has been questioned after the city council’s head of climate change and sustainability was unable to prove that a pledge to slash carbon emissions was on course.

Sandy Taylor insisted that Birmingham was making great strides towards reducing carbon, but admitted he had no data to demonstrate the extent to which the city was delivering on a target to cut CO2 by 60 per cent by 2026.

Mr Taylor found himself in difficulties when quizzed by a scrutiny committee.

Following a presentation in which he outlined numerous green initiatives, including the £1.3 billion Birmingham Energy Savers scheme which aims to end fuel poverty for 200,000 households through better insulation of Victorian and Edwardian properties, he was asked for evidence that the city was on track to hit the 60 per cent emissions reduction within the timescale set out.

Mr Taylor said it would be “very difficult” to be certain about the amount by which CO2 had reduced since a Climate Change Plan was agreed a year ago.

He told the committee: “I completely agree that there is data and statistics but we haven’t brought it to you in a way that would be useful.

“We do need effective monitoring of our progress.”

He rejected claims that city planning officials were obstructing green projects, insisting that “sustainability is at the heart of everything we do”.

Examples of Birmingham leading the way in sustainability included the city’s combined heat and power stations (CHP), where the heat generated by making electricity is recycled to provide heating and air-conditioning for buildings. Carbon savings from CHP are substantial, Mr Taylor said.

Over the next five years half of Birmingham’s street lights will be switched to energy-efficient LED bulbs, while plans to encourage electric cars and roll out more recharging points are under way.

CHP has been installed at the International Convention Centre in Broad Street, at Aston University and the Birmingham Children’s Hospital.

The intention is to encourage nearby businesses to tap into CHP and eventually extend the system across the city centre.