Earth to Paris

James Lovelock‘s search for life on Mars led him to conclude that the gases in a planet’s atmosphere indicated whether it harboured life or was dead. Through a series of complicated evolutionary dance steps life contrives to keep a planet habitable for life. Whether that life is intelligent or not is another matter.

Any extra-terrestrial observing Earth would conclude something momentous happened to our own atmosphere in the last 60 years. A continent sized hole appeared in the ozone layer – the layer that protects life from harmful radiation. The delicate balance of greenhouse gases started rising rapidly. The most important, carbon dioxide, rose rapidly from 280 parts million in the 18th century to 400 parts per million this year – a 43% shift. Unsurprisingly the planet’s temperature went up a notch (1°C or 1.8°F).

ET might conclude some rogue species has taken over and grown like a cancer out of control. They might be right. He would certainly put a watching brief on the third rock from the sun and will be wondering what happens next. Will Earth go into shock and enter a feedback loop where warming begets more warming and flips to an extreme Venus-like state? Or will we see another feedback loop where the information about the state of the biosphere feeds back to the perpetrators who can act on this information and moderate behaviour?

If the aliens are monitoring the airwaves from the Paris climate summit this week they may well be surprised by the news that the growth rate of emissions of carbon dioxide look like they are stalling. Indeed, scientists from the Global Carbon Project say in 2014 emissions grew just 0.6% compared with a 2.4% annual increase over the last decade. Incredibly, they predict emissions rates —> Read More