No fans. No snack stands. No tour buses or hotel bookings. To many, this year's Tokyo 2020 Olympics may seem like no fun. But to environmentalists, the pared down approach is exactly what's needed in a world confronting climate change.

Initially, the Tokyo Organising Committee had estimated the mega-event would result in emissions of some 2.73 million tons of planet-warming carbon dioxide — more than what the cities of Vancouver or Melbourne reported emitting in all of 2019.

But without the traveling crowds to feed, house and entertain, that carbon footprint will be cut by 12%, to about 2.4 million tons of carbon dioxide, the organizers said in a sustainability report this month.