EXPERTS have claimed planes from Gatwick airport will release almost one million extra tonnes of greenhouse gas per year if new plans go ahead.

Earlier this month, Gatwick Airport Ltd unveiled its proposed master plan to use its backup runway for routine flights, increasing departures to 70 planes every hour.

But the Aviation Environment Federation (AEF) campaign group said the plan would cause annual carbon dioxide emissions to increase by an extra 930,000 tonnes.

Director Tim Johnson claimed the additional CO2 will “heighten the scale” of climate change in the UK.

“This will threaten the UK’s ability to meet its climate target of net zero emissions by 2050,” he said.

“Based on the analysis Gatwick has provided, they have only looked at the emissions they are directly responsible for in terms of staff travel, heating, and electricity.

“They have only measured aircraft emissions up to 3,000 feet, which is only a few miles per flight.”

Government estimates have shown Gatwick will handle 52 million passengers every year by 2050 if the airport remains as it is.

This meant it will generate 2.7 million tonnes of CO2 per year.

But Gatwick’s masterplan claimed up to 70 million will use the airport annually by 2033 if its back-up runway comes into regular use.

The AEF claimed the number of planes used for this many passengers would create 3.6 million tonnes of CO2 every year.

Mr Johnson said the AEF’s carbon estimate could be conservative as far more passengers could use Gatwick by 2050.

“We don’t deny that aircraft will be more efficient in years to come,” he said.

“The Government has already factored in predictions planes will be 40 per cent more efficient by 2050, which is quite aggressive.

“But better technology is definitely not enough to keep emissions to net zero by 2050.

“We need to limit the number of people travelling by plane.”

A Gatwick spokesman said it would “question the figures” in the AEF report.

He said: “Any future growth at Gatwick will be delivered in a sustainable way and in line with Government policy.

“We will carry out a number of detailed studies to assess the impacts and benefits of our standby runway plan on our local region and will be consulting on the plans next year.

“The detailed work on carbon emissions relating to the master plan proposals will commence shortly to inform the planning process, so it is not possible to calculate any figures with any accuracy at this stage.

“With this in mind, we would question the figures in the AEF report because more detailed information is needed for accurate predictions to be made.”

The spokesman added Gatwick was part of the United Nations “Corsia” programme, which offsets the airport’s carbon emissions.

He claimed the airport was halfway to its goal of net zero carbon emissions.

“In terms of achieving the net zero goal, Government policies to encourage market innovation and investment, particularly in developing clean fuels will be pivotal, while also supporting UK jobs and growth,” he said.

“Gatwick has a strong track record of tackling carbon attributable to the airport and we are already playing our part as our facilities are half way to net zero emissions from energy.

“This has been achieved by purchasing renewable electricity and having a strong focus on energy efficient systems.

“We will continue to progress this agenda.”