LONDON (GN): Delta Air Lines said Friday it will invest $1 billion over the next 10 years in measures designed to offset climate-warming carbon emissions from its planes. Delta said the money would go into things such as boosting fuel efficiency and investing in efforts to remove carbon from the atmosphere by planting trees and restoring wetlands. Aviation accounts for about 2% of global carbon emissions, but those emissions are rising with the growth in air travel. Airline industry officials worry about the emergence of flight-shaming — reminding people of airplanes’ toll on the environment — and its potential to reduce demand for air travel. Airlines have taken small steps, including investments in alternative-fuel start-ups. They also point to their purchase of newer, more fuel-efficient planes in recent years. However, revolutionary changes such as powering a large number of airline jets with electricity or biofuels are seen as years if not decades away. Delta, which has an older fleet on average than many of its major competitors, has gotten poor marks for fuel efficiency. In a report last September, the International Council on Clean Transportation ranked Delta eighth among 11 U.S. airlines in fuel efficiency per passenger on domestic flights in 2017 and 2018.