The global loss of wildlife is “significantly more alarming” than previously thought, according to a new study that found almost half the planet’s species are experiencing rapid population declines.

Humans have already wiped out huge numbers of species and pushed many more to the brink – with some scientists saying we are entering a “sixth mass extinction” event, this time driven by humans.

The main factor is the destruction of wild landscapes to make way for farms, towns, cities and roads, but climate change is also an important driver of species decline and is predicted to have an increasingly worse impact as the world warms.

The study’s authors analyzed more than 70,000 species across the globe – spanning mammals, birds, reptiles, amphibians, fish and insects – to determine whether their populations have been growing, shrinking or remaining steady over time.

They found 48% […]