Scientists identified 9 planetary parameters in a paper published in 2009, as a measure of the effect we have on our environment. A recent paper evaluated the current status of these parameters and concluded that we have crossed 4 out of the nine boundaries placed on these parameters. Which means we are currently in an area where science is uncertain what the effects will be. The bad news however is that within decades to a century we will reach a point where science doubts the planet can support us any longer.
Explanation of the planetary boundaries:
The past 10.000 years called the Holocene was a period of environmental stability which allowed humanity to flourish, however we are now affecting our environment in such a strong rate that we have entered and era called the Anthropocene (from the ancient Greek, anthropos = man). Environmentalism has never been about saving the planet, the planet has endured many eras of extinction and life recovered every time, we’re the living proof of that. Environmentalism is about preserving our (and other) species. We tend to forget we live inside a thin film of air on a rock floating in space at a speed of 113.000 km/h, the nearest star (Alpha Centauri) is 4.37 lightyears (4.1 x 10^13 km, thats 41 times a million, times a million) away and the closest presumably habitable planet a multiple of that. We have no where to go. It is time we started to take care our rock, it’s the only one we have.
Here’s a picture depicting how thin and fragile our atmosphere really is:
Washington Post article:
More on planetary boundaries: