Climate change in context: 65 million years of temperature swings.…

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http://joannenova.com.au/2010/02/the-big-picture-65-million-years-of-temperature-swings/
Climate change in context: 65 million years of temperature swings.

"With so much volatility in the graphs, anyone could play “pick a trend” and depending on which dot you start from, you can get any trend you want. "

"If you wonder where today’s temperature fits in with the grand scheme of time on Earth since the dinosaurs were wiped out, here’s the history. We start with the whole 65 million years, then zoom in, and zoom in again to the last 12,000 from both ends of the world. What’s obvious is that in terms of homo sapiens history, things are warm now (because we’re not in an ice age). But, in terms of homo sapiens civilization, things are cooler than usual, and appear to be cooling.

Then again, since T-rex & Co. vanished, it’s been one long slide down the thermometer, and our current “record heatwave” is far cooler than normal. The dinosaurs would have scoffed at us: “What? You think this is warm?
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My main point is that natural variation is so large, even if we cease all emissions completely, the climate will still change (just look at the graphs). The cost of (possibly) slightly influencing this change is so great, why not spend a lot less adapting to it? Since we don’t know if the long-term climate is cooling or warming (I bet on cooling long-term), we could spend trillions to cut emissions, only to have the climate cool catastrophically on its own. What then? Pump as much CO2 into the air as possible?

Warming is not a killer, but global cooling is. It would only take a few years of global crop failures from cold weather to put populations at serious risk. Both the Antarctic and Greenland ice sheets are thickening: Leave anything on the ice, and it gets buried pretty fast (for example: the US South Pole Base was recently reconstructed because the old base was being crushed by snow and ice, and WWII planes lost on Greenland’s southeast coast, were covered by 264 feet of ice in 50 years: see the image below). This is not rocket science. Sure, the sea-level edges are retreating (that is why we call them the ablation zones of a glacier), but they represent a minute portion of the continent-scale ice mass."

http://joannenova.com.au/2010/02/the-big-picture-65-million-years-of-temperature-swings/