British Airways has committed to reviewing its practice of getting planes to carry tons of excess fuel to avoid refueling at its destination airports2 Emissions.

BA's parent company IAG, Willie Walsh, admitted that the use of "fuel tanking" in the industry, despite the financial incentives that underpin the practice, "may be wrong" due to its environmental impact.

Critics said the widespread use of fuel tankers had challenged airlines' commitment to reducing their impact on the environment.

The information on fuel surplus came from a BA insider during a BBC panorama investigation.

The IAG has recently sought to improve its environmental standards to become the first airline group in the world to commit to net zero emissions by 2050.

The Climate Change Committee considers it necessary, affordable and desirable, to reduce greenhouse gas emissions to zero by 2050. Here are some of the actions needed to achieve this:

• The sale of petrol and diesel vehicles is ideally prohibited until 2030 and 2035 at the latest.

• quadrupling clean electricity generation from wind, solar and possibly nuclear power plants, and batteries for storage and connection with Europe to share the burden.

• Connection of new houses to the gas network by 2025 with boilers using clean hydrogen or being replaced by electrically operated heat pumps. In addition, all households and appliances are highly efficient.

• The consumption of beef, lamb and dairy products decreases by 20%. However, this is much lower than recommended in other studies, and a greater shift to a plant-based diet would make it easier to reach the zero target.

• One-fifth of all farmland – 15% of the United Kingdom – is used for tree planting, biofuel cultivation and peatland restoration. This is important to extract CO2 from the air and to compensate for unavoidable emissions from cattle and airplanes.

• 1.5 billion new trees are needed, which means that by now, more than 150 football fields per day will be covered with new forests by 2050.

• Flying would not be prohibited, but the number of flights will depend on how much airlines using electric aircraft or biofuels can cut emissions.

According to BBC reports, a recent BA flight to Italy took almost three tonnes more fuel on board. This represents a cost saving of only £ 40, but means an extra 600 kg of CO2 was emitted.

Speaking to analysts, Walsh said last week that BA has often used fuel tankers to save money, citing the example of Glasgow Airport, where jet fuel is 25% more expensive than Heathrow.

However, Walsh said that BA is now reflecting on its position on the practice. "We refuel today. We challenge this and ask ourselves if this is sustainable and if we should factor in the environmental impact of it.

"The financial savings are clearly an incentive for us to drive tankers. But maybe that's wrong. "

BA said its fuel tanker produced 18,000 tonnes of additional CO2 per annum – less than 0.1% of its total emissions – and that it represents 2% of tankers in Europe.

According to a report by Eurocontrol, which coordinates air traffic control for Europe, airlines save a total of EUR 265 million (GBP 229 million) per year through the use of European practice – but at the cost of an additional 901,000 tonnes of CO2,

John Sauven, Executive Director of Greenpeace UK, said it's a "classic example of a business that is putting profits before the earth, and they're keen to pour more fuel into the fire to boost their profit margins."

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Meanwhile, a climate expert described a climate protection system offered to Ryanair's customers as "totally inadequate". Passengers can make a voluntary donation of 1 € at the time of booking.

Simon Lewis, Professor of Global Change Science at University College London, said that Ryanair's tree planting programs financed in Ireland and Portugal would only offset 0.01% of the airline's emissions. He said, "For me, that's a green gimmick."

Michael O'Leary, CEO of Ryanair, said to Panorama: "From small acorns grow mighty trees."