"Ecosia’s operation leaves a negative CO2 footprint on the world – their servers operate on 100% renewable energy and each tree that they plant removes 1 KG of

"Ecosia’s operation leaves a negative CO2 footprint on the world – their servers operate on 100% renewable energy and each tree that they plant removes 1 KG of CO2 from the atmosphere." But then later it says that Ecosia search results are based on Bing? If they are effectively searching Bing in the Background, wouldn't they have to factor in the CO2 footprint of a Bing search?