United Airlines said Thursday that the company plans to totally offset its greenhouse gas emissions by 2050 through a technique that captures carbon directly from the atmosphere and stores it in the ground.  

United said it plans to invest several million dollars in a company that specializes in such technology, 1PointFive, which was created by Occidental Petroleum Corporation and private equity firm Rusheen Capital Management, according to a statement. 

United said the direct air capture initiative comes in addition to the company's ongoing efforts to invest in and develop sustainable aviation fuel. 

"As the leader of one of the world's largest airlines, I recognize our responsibility in contributing to fight climate change, as well as our responsibility to solve it," the US air giant's CEO Scott Kirby said in the statement. 

The use of fuel-hungry planes means that aviation accounts for about two percent of global carbon dioxide emissions, according to the International Civil Aviation Organization. 

It is no longer enough to try to compensate for carbon emissions through offsets such as planting trees, Kirby said during a conference call. 

"The reality is that traditional carbon offset programs simply can't come close to offset the 4,000 times increase in manmade carbon emissions" since the industrial revolution, he said. 

Direct carbon capture and storage in man-made sinks "is the only solution that is real, permanent and scalable," Kirby said. 

United's investment will help 1PointFive build a US plant that can capture and store a million tons of CO2 per year, the equivalent to planting 40 million trees, according to the airline.