Google launched a new feature on Wednesday that shows users the environmental impact of flights. Starting today, users will see carbon emissions estimates for nearly all flights in the search results. The estimate is visible next to the price and duration of the flight. Google notes that the new feature will allow users to factor carbon emissions into their decision alongside cost or timing when it comes to booking travel.

The estimates are flight-specific and seat-specific. For instance, the emissions estimates will vary when looking at economy or first-class seats, as seats that take up more space account for a larger share of total emissions. Additionally, newer airplanes are generally less polluting than older ones.

Flights with lower emissions will be labelled with a green badge. Those who want to prioritize carbon impact when searching for a flight can sort through results so that the flights with the lowest emissions are at the top of the list. Flights are labelled as higher, typical, lower or unknown emissions.

Google calculates the estimates by combining data from the European Environmental Agency with flight-specific information provided by airlines regarding details such as aircraft type and the total number of seats. The search giant notes that actual carbon emission may vary and depend on factors such as aircraft model and configuration, speed and attitude of the aircraft along with the distance between the origin and destination. The company plans to continue revising carbon emissions over time to improve accuracy.

“This update to Google Flights is just one of the many ways we’re helping people make sustainable choices in their everyday lives,” Google’s vice-president of travel products, Richard Holden, said in a blog post.

This latest update to Google Flights comes as the company just launched eco-friendly routing in the U.S. for iOS and Android users. Eco-friendly routing gives drivers the choice between the fastest and most fuel-efficient route. Google believes the new feature could allow Maps users to avoid over 1 million tons of carbon emissions per year. Eco-friendly routing is expected to launch in Europe next year.