With a fan base of 3.5 billion – almost half the world's population – soccer is the most popular sport in the world and its carbon footprint is huge. Thanks  emissions caused by  with energy use in stadiums, fan and team travel, broadcasting, a multi-billion dollar market for kits and other merchandise, and even match food, the beautiful game takes a not-so-beautiful toll on the planet's climate. With international competitions set to get even bigger - the 2026 and 2030 FIFA World Cups will be held on more continents with more teams - what is football doing to reduce its emissions and reduce its carbon footprint?

What is the carbon footprint of football?

Estimates of football's total emissions impact are often too low because they usually do not include vital activities such as stadium construction. Meanwhile, club emissions are difficult to calculate because they vary by size and location. One thing experts agree on is that the biggest contributor is travel – of spectators and teams. (Thomson Reuters Foundation)