Within a century, the Earth may stop being a “safe operating space” for humans
Well, here’s hoping you weren’t already having a bad day, because if so this news may push you over the edge.
The Earth has just passed the fourth of nine markers that may lead to a radical shift in the Earth’s environment. And if things don’t change immediately, the end of our current way of life could come in “decades out to a century.”
According to a report from the Washington Post, 18 scientists came together to publish a paper in the Science journal that outlines the way the Earth is changing. The paper claims that within decades, the Earth may cease to be a “safe operating space” for humans. The scientist go on to discuss nine “planetary boundaries” that beyond which it is unknown what will happen, but it won’t be good. And we’ve already passed four.
Breaking the boundaries
The boundaries that we’ve already passed are: the extinction rate of several species, deforestation, the level of carbon dioxide in the atmosphere, and the amount of nitrogen and phosphorous from fertilizer found in the ocean.
The nine boundaries were first outlined by scientists in a 2009 paper. The research defined limits on the amount of change we can inflict upon the environment before the planetary conditions become unknown, and likely unsafe to humans. The boundaries are theoretical, and include ozone depletion, freshwater use, ocean acidification, atmospheric aerosol pollution, and new chemicals that come along with mutated organisms.
Once the limits of each boundary are crossed, the conditions become foreign to humans. Before that though, but after crossing the boundaries, there is a small “zone of uncertainty” that is like a warning light on a car. There is still a chance to pull back during this zone, but it is a dangerous time.
“The boundary is not like the edge of the cliff,” Ray Pierrehumbert, an expert on Earth systems at the University of Chicago, told the Washington Post. “They’re a little bit more like danger warnings, like high-temperature gauges on your car.”
Pierrehumbert went on to say that a planetary boundary “is like an avalanche warning tape on a ski slope.”
It’s not all bad
The paper does point out some good though. The ozone layer, for example, is recovering nicely after world leaders joined together in the 80s and 90s to limit the introduction of chlorofluorocarbons (CFCs) that created an expanding hole in the ozone layer. Those actions prevented an environmental disaster.
With that said, the depletion of the ozone layer is one of the nine boundaries. If we crossed irreversibly passed the line with the ozone layer, humanity would not have immediately died out, but the Earth would become a much less hospitable place for us.
There is also room for debate regarding the findings. The authors of the paper themselves are willing to concede there is a lot of uncertainty in their research.
The key is that the boundaries just signify the balance of the Earth’s biosphere as it stands today. If the boundaries continue to be passed, it may lead to something like a new ice age, or a drought of epic proportions. It doesn’t necessarily mean humanity will die off. Our way of life as we know it though, will radically change.
If it does, the odds are the change will not be good.
There is evidence that a shift in boundaries in the past may have actually been beneficial. The rise in agriculture, for example, was likely a response to the expansion of hunters across the world that was forced by the availability of wildlife. That in turn helped give rise to the necessity of a stable food source.
Of course, there was likely a period of significant starvation leading up to that.
There is still time to reverse the effects and ensure the continuation of our current way of life, but not much. The rising CO2 levels, for example, have crossed the safe-operating-zone boundaries for CO2 that was 350 parts per million in the atmosphere. We are currently at 400 ppm, but that zone of uncertainty goes up to 450 ppm.
Pierrehumbert – who was not part of the study, but agrees with the findings – also warns against an over reliance on technology to save us.
“The trends are toward layering on more and more technology so that we are more and more dependent on our technological systems to live outside these boundaries,” Pierrehumbert said.
“It becomes more and more like living on a spaceship than living on a planet.”