DHAKA: There are just over three trillion trees on Earth, according to a new assessment.

The figure is eight times as big as the previous best estimate, which counted perhaps 400 billion at most

It has been produced by Thomas Crowther from Yale University, and colleagues, who combined a mass of ground survey data with satellite pictures.

The team tells the journal Nature that the new total represents upwards of 420 trees for every person on the planet, reports BBC.

The more refined number will now form a baseline for a wide range of research applications - everything from studies that consider animal and plant habitats for biodiversity reasons, to new models of the climate, because it is trees of course that play an important role in removing the greenhouse gas carbon dioxide from the atmosphere.

'Forest system in numbers'

But Dr Crowther cautioned that the higher number did not of itself change anything.

He told the BBC's Science In Action programme: "It's not like we've discovered a load of new trees; it's not like we've discovered a load of new carbon.

"So, it's not good news for the world or bad news that we've produced this new number.

"We're simply describing the state of the global forest system in numbers that people can understand and that scientists can use, and that environmental practitioners or policymakers can understand and use."

Key to the new estimate is the greater use of ground-truth data. The team collected tree density information from over 400,000 forest plots around the world

BDST: 1527 HRS, SEP 03, 2015
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