After the devastation that yet another "freak" weather event wrought last week, the question must be asked: how many more "Sandys" have to occur before people start seeing greenhouse gas pollution as the main underlying cause?
There are glimmers that Americans, at least, might be finally not only getting the message about climate change, but are increasingly willing to link it to extreme weather. The mayor of New York, Michael Bloomberg last week made a surprise announcement backing Barack Obama, citing — among other things — his stance on climate change.
Scientifically speaking, we currently lack the knowledge to attribute individual events purely to climate change, yet we know that the weather is definitely getting weird.
National Geographic asked recently, "What's up with the weather?" concluding that it's probably a combination of human-made shifts in Earth's climate and a natural stretch of bad luck; Dr Michael MacCracken, Chief Scientist at The Climate Institute, told me a couple of months ago that meteorologists are starting to find their empirical "rules of thumb" aren't working as well as they used to.
Importantly, evidence is continuing to mount that a warmer Arctic affects the polar jet-stream in a profound way, leading to a wavier motion and increased formation of blocking patterns. Is it merely a coincidence that warmer sea-temperatures and an unusual meterological blocking ridge were both major factors in Sandy's scale, size and path? The link between extreme weather and climate is getting stronger and harder to deny.
So, what's up with the climate?
It's starting to become apparent that, paradoxically, we know both less and more about the climate: more ways that the climate can be influenced (by mechanisms such as the polar jet-stream, for example) but less about how these mechanisms actually work and interact with one another. Our state-of-the-art models are lagging painfully behind reality, and it's not just a question of adding more raw computing power — although that would help enormously.
Recently, there was a brief media blitz when the Arctic ice-cap reached a record low in its annual melt, but unless you're a climate junkie, the reported facts and figures probably don't mean all that much.
For anyone left in any doubt as to how bad the situation is, the diagram below shows how satellite measurements of the ice coverage (the thick red line) stack up against computer models from the last Intergovernmental Panel on Climate Change (IPCC) report.
Least understood are the so-called large-scale climate discontinuities. Some of these — such as the carbon cycle becoming unbalanced — are predicted to have a low probability of happening, yet have potential impacts that are so far out of the realm of everyday experience, to even mention them would be tantamount to scare-mongering. While it may not be a pleasant thought, we need to ask ourselves if our best models are capable of getting it so spectacularly wrong about the Arctic, can we afford to be confident about such predictions?
It's not as if we don't have solutions on hand: the technology that can take us to a decarbonised economy already exists, such as baseload solar thermal power stations, solar voltaic power and wind farms. One of the great things about renewable energy is that the more you use, the cheaper it gets (unlike fossil-fuels where the more you use, the more expensive they become). Just imagine how much would be possible if the multi-billion dollar subsidies each year to the fossil-fuel industry were instead invested in clean energy.
There are many obstacles in the way of this becoming reality, but an example of a real success story is to be found in Canberra: ACT Labor has shown tremendous courage by recently announcing the jaw-dropping target of 90 per cent renewables within just eight years, making the territory a world leader. Partnership with the Greens (who still hold the balance of power) and concerted effort from community groups such as "Canberra loves 40%" were essential ingredients in creating such ambitious goals.
As much as some would like it to go away, the sad reality is that climate change will probably get worse over the next few decades no matter what we do. The psychological toll this will take on all of us cannot be overestimated, yet this could easily become an excuse to prevaricate. Or worse.
Future generations will no doubt look back and ask what was the moment we finally made the decision to do something about climate change. I hope that moment is now.
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