Even without global warming, acidified ocean waters and an increasing scarcity of mineral oil are more than enough reason to break our addiction to fossil fuels. [6 October 2009 | Peter Boyer]
The climate debate goes something like this: our burning of fossil fuels has caused the world to get warmer, leading to melting ice, rising seas, changing rainfall pattens and more frequent extreme weather events. Or it hasn’t, if you happen to disagree with the science.
If you’re one of those disagreeing people you’ll focus your attack on temperature figures. Last week, for instance, the Nationals’ Senator John Williams assured electors that that global temperatures were in fact dropping.
Senator Williams should probably talk to one of the glaciologists measuring diminishing ice sheets and sea ice in polar regions, which is pretty strong evidence of a general warming trend. Such evidence seems not to matter to him.
But let’s pretend for a moment that he’s right. With global warming out of the equation, we can stop worrying about burning coal, oil and gas, surely?
If only it was that simple. Here are two utterly compelling reasons, independent of global warming, for prompt action to reduce our reliance on fossil fuels: acidifying oceans and peak oil.
Our oceans are ailing, and one of the main reasons is the rising amount of carbon dioxide in our atmosphere. Within the past 200 years that amount has jumped about 40 per cent above its highest previous level since humans first walked the planet.
A quarter of that atmospheric carbon dioxide is absorbed by the oceans, which we might celebrate except for the fact that this additional carbon dioxide is causing ocean waters to become steadily more acidic. The long-term results may be devastating.
Over millions of years, marine life has become used to living within a very narrow alkaline-acid band — close to 8.16 on the pH scale. Our fossil-fuel use has now reduced that to just over 8, and by 2100 it will have dropped to about 7.8.
It doesn’t sound much of a shift, but it takes very little change to make a big difference, and this is happening in a few human lifetimes when in nature such changes would occur over thousands of years. Acidification will spell doom for some species, especially in cooler ocean waters.
Preliminary results of surveys by scientists from Hobart’s Antarctic CRC have shown that the capacity of several key marine species to form calcite deposits, such as outer shells, is already being inhibited by increasingly acid ocean water.
Ocean acidification will have an impact up and down the marine food chain, with a potential to cause collapse of whole ecosystems. We’re not just talking about food here; there will be an inevitable impact on microscopic species that together produce half of the oxygen we breathe.
Tasmania’s experience of ocean acidification will unfold slowly, though some side effects may be felt more abruptly. But another phenomenon, also resulting from fossil fuel burning and also independent of global warming, will affect us much more quickly, and that’s peak oil.
Peak oil is a concept that’s been around since the 1950s, when a geoscientist named Marion King Hubbert predicted that the rate of oil extraction in the United States would reach a maximum by 1970, after which it would inevitably fall away. Time proved him correct.
Hubbert’s thesis has now gone global. It’s hard to get an exact handle on the global scene because oil-producing people prefer not to reveal troubling statistics, but it’s now accepted that peak oil has either already happened or will happen soon, somewhere between 2005 and 2020. The strongest sign will be an underlying steady rise in the price of oil.
Regardless, the inevitability of peak oil should really be focusing our minds, right now. Oil touches every aspect of our lives — how we move about, the things we buy, our clothes and our home fittings, how we package things, fertiliser, medicines… the list is practically endless.
It should especially be focusing our minds here in Tasmania, where our car-dominated lives depend heavily on imported fossil fuel — two tonnes of it per head of population per year. If our planners and politicians are not mentioning peak oil in every study and every speech on transport, we should be asking why.
Here’s the bottom line. Even discounting any impact from global warming, there’s no future for us in continuing to burn fuel from the ground. We have to get ready for a life without it.
• Everyone is invited to attend the day-long Climate Action Forum in Hobart on Saturday (10am to 4pm) to look for the best ways for Tasmania to address the climate challenge. The forum, to be at the Phillip Smith Centre, 2 Edward Street, Glebe, will include speakers, discussions, films and lunch.