Singapore's Million Tree Plan Can Slash AC Bills, Scientists Find

Singapore is planting a million trees to help cool down the city.

Trees give shade, which makes streets and people feel less hot on sunny days.

Scientists found that shade can make people feel about 3 degrees cooler, even if the air temperature only drops a little.

The biggest savings come when trees shade buildings, not just streets, because that lowers the need for air conditioning.

In hot and humid Singapore, this could cut cooling electricity use by 6 to 9 per cent.

In drier cities like Riyadh and Phoenix, the savings are even bigger, around 17 per cent.

But there is a catch: trees add moisture to the air in humid places, and removing that moisture uses extra power.

So the best amount of trees is around 40 per cent coverage, not more.

Also, too many trees can trap heat at night or block cool breezes.

Overall, trees help, but the details matter for how much they save.