How Human Beings Are Downgrading Life on Planet Earth

"We live in the Anthropocene, as some scientists have come to call our new geologic era. The term acknowledges the fact that human beings—nearly 7 billion strong and growing—have so much influence over the life, geography and even chemistry of planet Earth that we're now essentially responsible for the whole show. For good and for ill, the planet from now on will be what we make of it.
But just because our actions are shaping the future of the planet—and everyone and everything else that rides on it—doesn't mean that we always know the effects of what we're doing. Case in point: in a new review in the July 14 Science, a group of researchers persuasively argue that one of the biggest impacts that human beings have had on the planet isn't necessarily deforestation or climate change or pollution. It's the extirpation—through hunting, habitat loss or disease—of apex predators, species like tigers or wolves or sharks that skit high on the food chain. When those species go, there can be drastic knock-on effects for animals and plants below them, as the paper argues:
The loss of apex consumers is arguably humankind's most pervasive influence on the natural world. This is true in part because it has occurred globally and in part because extinctions are by their very nature perpetual, whereas most other environmental impacts are potentially reversible on decadal to millennial time scales. Recent research suggests that the disappearance of these animals reverberates further than previously anticipated (6–8), with far-reaching effects on processes as diverse as the dynamics of disease; fire; carbon sequestration; invasive species; and biogeochemical exchanges among Earth's soil, water, and atmosphere."
via TIME.com /read more