Surfing Climate CHaos
May. 25th, 2017 07:59 pmThe plot of this epic disaster thriller goes like this: The global average surface temperature of the Earth is a function of global average atmospheric CO2 concentration. Humans are adding CO2 to the atmosphere by burning fossil fuels, causing global average surface temperature to rise. A higher global average surface temperature will cause extreme weather, such as droughts, floods, and hurricanes and other phenomena such as seal level rise and ocean acidification. Therefore, humans must stop burning fossil fuels, develop renewable energy sources and help undeveloped countries rise up from poverty in order to accommodate changing climate conditions.
This story depends on one basic assumption: that atmospheric CO2 acts as a thermostat for global average surface temperature. That is, there is a linear relationship between a change in CO2 and a subsequent change in temperature. And that change in global average surface temperature is meaningful in terms of the global climate.
Unfortunately for this plot line, atmospheric/ocean/lithosphere interrelationships are not linear. They are complex and chaotic. Raising or lowering atmospheric CO2 does not always raise or lower global average surface temperature in lock step. Modern CO2 and temperature records are a perfect example: CO2 levels have risen steadily since 1958; global average surface temperature has risen and fallen at varying rates.
Think of a surfer, standing beside his woody, his wet suit half dangling from his hips, watching the sets roll in at The Pipeline. The waves are pretty regular, but there is a suggestion of a variable pattern: 3 to 4 curls of increasing size, then a couple of big ones. Then another set of small waves, then a big one. Every now and then a huge waves crashes against the rocks. Cheers and whistles all around.
But one thing the surfer can’t do is predict when that world class wave will come in, or which wave is the big one swelling up behind his surfboard when he’s waiting to catch the perfect wave. That’s because waves at the shoreline, like climate around the world, are the result if intersecting cycles that crash together, rebound and reflect, never completely repeating themselves as they form in endless patterns.
Climate scientists use global climate models to characterize climate patterns and project these patterns into the future, in an attempt to determine what the climate of the future may be, based on what the climate is today. They program their computers with contemporary and historic climate data and observed climate cycles, then the program is run in an iterative process, which repeats its calculations over and over again to achieve a model of yearly climate variation.
The problem is that the computer programmers do not know every single exact variable that influences natural climate variation, just as the surfer cannot know all the eddies, currents, wind and reflected waves that determine the pattern of the next wave approaching his board. Each iteration causes the model to veer off a tiny bit from what happens outside the window in the real climate. The model may be only off by .000001, but each iteration of the model multiplies that tiny error, creating an end result that is far different from the real climate.
In chaotic systems, tiny differences in initial conditions can result in huge variability out the other end. The flapping of a butterfly’s wings in Peru can influence the course of a hurricane in the Atlantic ocean.
In fact, to fully model the existing climate system of our planet would require a computer, well, equal in complexity to the Earth itself. Shades of Douglas Adams’ Deep Thought. And we really do live on that computer!
Since climate on the Earth is also influenced by natural cycles on our sun and our eccentric orbit around it, cosmic rays and frequency of supernovas in distant galaxies, one could say that we would need a computer with the complexity of the known Universe to accurately model our planet’s natural climate variation. And we already live in that computer, too.
Our surfer bobbing about on the waves has a far better chance of “predicting” the next big curl than all the global climate models in operation have of even semi-accurately projecting the Earth’s climate any useful distance into the future.
The question of what do we do about this unpredictability of future climate is not a scientific question, it’s an economic, philosophical, social, and governmental question. Since it involves the future of all life and the planet on which it all exists, what we do about climate changes strikes to the core of mankind’s relationship with the natural world.
The question is not “Can we stop climate change?” That question is easy and the answer is an unequivocal “No.” Natural climate variability is beyond our power to control, and we must get over thinking that we can.
The only solution possible to the problem of a varying climate is to paddle out to the right spot for the next set, have our wet suit zipped up and our board pointed toward the beach. When that big wave comes in, we’ll be ready for whatever it presents us.
Surf’s up!
