Is Tokyo rhe greenest big city in the world?

I was a bit taken aback by one of the commentators of the Tokyo Olympics Closing Ceremony claiming that Tokyo is one of the greenest cities in the world in terms of parks and tree cover (this is quite apart from Tokyo's pretensions to being one of the greenest big cities in terms of its environmental record).

This immediately rang false to me. Yes, it's probably geener than most of us assume, but one of the greenest in the world? Well, me being me, I immediately fact-checked it and, of course, it's not as simple as it appears.

My first attempt led me to MIT's Sensible Lab and the World Economic Forum's Treepedia project, and the big cities with the most tree cover listed there might surprise you:

• 19. Los Angeles, USA (15.2%)
• 18. Turin, Italy (16.2%)
• 17. Tel Aviv, Israel (17.5%)
• 16. Boston, USA (18.2%)
• 15. Miami, USA (19.4%)
• 14. Toronto, Canada (19.5%)
• 13. Seattle, USA (20%)
• 12. Amsterdam (20.6%)
• 11. Geneva, Switzerland (21.4%)
• 10. Frankfurt, Germany (21.5%)
• 9. Sacramento, USA (23.6%)
• 8. Johannesberg, South Africa (23.6%)
• 7. Durban, South Africa (23.7%)
• 6. Montreal (25.5%)
• 5. Sydney, Australia (25.9%)
• 4. Vancouver, Canada (25.9%)
• 3. Oslo, Norway (28.8%)
• 2. Singapore (29.3%)
• 1. Tampa, USA (36.1%)

So, no mention of Tokyo...

Another source, though, suggests that Tokyo does in fact have a whopping 52% tree cover. I'm not sure where that particular figure came from, but the article makes clear that much of this tree cover is in the western section of the city, Tama, a large area of natural forest and pine plantations that just happens to come within the demarcations of the city of Tokyo. Excluding Tama, the city, as we think of it, actually has a forest cover of around 23%, in line, the article says, with cities like New York (24%) and London (21%).  So, a pretty reasonable and perhaps surprising proportion.

Setting aside the fact that Treepedia has New York's tree coverage at 13.5% (not 24%) and London at 12.7% (not 21%), this is nevertheless quite impressive, and a far cry from the concrete jungle that most of us usually think of Tokyo as epitomizing. But it highights the fact that this is not an exact science, and, like most statistics, they can be used to prove pretty much anything (as this Guardian article also concludes).

What is more indisputable is that Tokyo, at over 37 million inhabitants, is the most populous city in the world (note, I do not say "biggest city" -  that would only get me into more statistical and semantic hot water!)