大象传媒

There are just over three trillion trees on Earth, according to a new assessment. This is eight times as many as the previous best estimate, which counted perhaps 400 billion at most. 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.

Phantom Road
Dr Heidi Ware of Boise State University and colleagues created a 鈥減hantom road鈥� using speakers to simulate the effects of traffic noise on the local bird populations. Almost one third of the bird community avoided the noise altogether, while those that remained showed a decline in body condition. Their findings suggest that noise pollution could have serious implications for the conservation of migratory birds.

El Ni帽o 2015
This week the World Meteorological Organisation issued a warning that the planet is at the beginning of one of the most severe El Ni帽o events on record. El Ni帽o being an event where the waters of the Pacific are abnormally warm, and start to distort weather patterns around the planet.

(Photo: Autumn sun pours golden light on trees and morning mist 漏 AFP/Getty Images)