James Hansen at NASA has stated that a safe level of CO2 in the atmosphere, one that can sustain life as it has developed up to this point, is 350 parts per million. This and all other predictions and extrapolations relating to climate changes should be taken with a grain of salt. We humans have very little evidence to draw from in forming these concepts and have been collecting data for a very short time in the grand scheme. What’s more, we have not witnessed events and changes like these in the climate since we have been keeping.

So we’re speculating. The best and the brightest of our experts around the world are making predictions left and right about what may happen as the world warms. There’s the International Panel on Climate Change at the UN for example, a coalition of many concerned scientists furiously collecting and examining evidence and releasing findings every six years or so. What’s interesting about these findings is that they are continually proving themselves wrong. The distressing part is that they are consistently underestimating the effects of the warming climate on our world. In the case of the IPCC, they usually release multiple scenarios, best and worst cases. Unfortunately even their doomsday scenarios are turning out not to be doomish enough to compete with reality.

So when Hansen tells us that 350 is the number we should be shooting for (a number already almost one hundred points higher that the 260-280 ppm we’ve had all through the period during which civilization has formed), he might be excused for a hint of wishful thinking. (This is in no way to disparage the hard and thorough work of Hansen and his team). The problem is we’re already at 391 ppm and the skies the limit at the rate we’re going.

Advertisements