The reason life survived on Earth for so long, and blossomed into animals, and now mind, is that the planet is equipped with homeostatic mechanisms (homeo means similar in Greek, and stasis, standing still). However, those mechanisms tend to be geological.
Human civilization is now having an impact on the biosphere of a violence probably never seen before. The changes are faster than what geology, or even life, can accommodate.
Some will brandish the impact of the Yucatan asteroid, and claim that was worse; however that’s just a theory: the biosphere was clearly under stress at the time from the Deccan Traps eruptions, and had been under that stress for hundreds of thousands of years, if not millions. At its worst, the Asteroid was just the straw which broke the Camel’s back.
2015 will be the warmest year since the end of the Eemian, 115,000 years ago. So why are record low temperatures appearing just south of Iceland? Yes, record lows, lower than ever recorded.
That was fully expected, and a demonstration of Non-Linearity of the incipient global warming. A phenomenon is linear when it looks like a line. Global warming is not going up like a line, as some places are warming at a rate ten times higher than the average, and some regions are cooling (and some are cooling spectacularly, off Iceland and some seas around Antarctica, for reasons related to warming).
The Dryas events were extremely fast and pronounced cooling events which happened several times during the period 10,000 years to 15,000 Before Present. Some lasted around a millennium, others, just a century. They vanished as fast as they came. They are named after a tundra flower, the Dryas. In Scandinavia forests were replaced by tundra graced with Dryas (hence the name). In Britain, average temperature collapsed to minus 5 degree Celsius, and glaciers formed at elevation.
These spastic events of drastic cooling, while, overall, de-glaciation was going on, long remained a mystery. Overall, the great glaciation which had brought glaciers down to New York, was on its way out, the planet was globally, irresistibly warming. So why would temperatures collapse in some places around Greenland by 15 degrees Celsius? The solution to the Dryas events’ spastic glaciation riddle? The same as always! Warming is non-linear.
What’s the theory? The details are uncertain, but we know that the Gulf Stream (aka the North Atlantic “Conveyor”) shorted, literally: analyses of deep sea sediments have shown this. The conveyor sends an enormous current of warm tropical waters northward.
When the warm tropical waters become very cold between Iceland and Spitzbergen, they sink to the bottom of the sea, and head south. This sinking, plus the pushing by trade winds in the tropics, is what provides the energy of the Gulf Stream.
However, if the warm tropical waters are capped by a very cold, but light sweet(er) water lid, they will get cold early, and sink before Iceland. This is what happened in the Dryas events.
Was it in response to a sudden influx of fresh water from Lake Agassiz and deglaciation in North America, and Greenland? Sudden freezing there would have removed the freshwater lid, hence the brutal switchback to warming after the brutal cooling. By the way, the sea level rising speed responded quickly, by a factor of three. After the typical Dryas cooling, oceanic rise rebounded to 18 millimeter per year right away (this shows that those who expect a slow rise of sea level rise are deluding themselves, or, more to the point, are trying to delude us!)
Nowadays a Dryas-like mechanism would have to rest on the melting of Greenland alone (that’s the only place with significant ice). This is, of course, insufficient, but summer 2015, cool and rainy over the northern North Atlantic is evidence that the effect is on. Scientific analysis confirms it. See: “Exceptional Twentieth Century Slow Down of Atlantic Ocean Overturning Circulation” (Nature, 23 March, 2015).
The exact nature of what is going on at this point is a matter of debate among experts. What is sure is that something is going on.
A similar situation beckons in Antarctica, where ice shield melting creates a freshwater lid all around which in turn freeze, extending the ice cap in the Austral winter.
When considering nonlinearity, subtlety and surprises are of the essence. This is true in physics, as it is in psychology, history, or politics.
And the morality in all this? The USA has played god. The European Union made a honest to goodness effort to reduce CO2 emission, while the USA, paying lip service to the opposite of what it was doing went right ahead, with its factory, the Plutocratic Republic of China, to use and abuse fossil fuels as never before.
So now what? Is god still American, as usual? At first it seems so: the USA started to frack massively and massive amounts of fossil fuels were extracted from the USA’s generous soil. When American companies tried the same in Poland, it failed: the underground god (Pluto?) did not cooperate: Polish soil is adverse to fracking.
Here comes the punchline: sea level has been rising fast along the Eastern seashore of the USA. Actually, three to four times faster than the world average. That’s more than one centimeter per year.
Why? Imagine a traffic jam. Or rather a crash ahead: things come to a halt, cars, water piles up behind. Maybe the Washington politicians will soon have to learn to swim, and not just against the tide of world public opinion.
The USA is going to be punished with its own instruments. Meanwhile 20 countries formed the V20, a group of twenty countries whose existence is immediately threatened by global warming, although they caused it not.
A Two Degree Celsius rise of temperature is indeed way too much: nonlinearity is upon us. Evil is always nonlinear.