Some thoughts on global warming

Recently a friend sent me some information on an initiative involving electric cars. Great idea, and I’m very keen on a number of levels.

But I did remark that I have long been a Global Warming sceptic, which surprised him. Being permaculturists, we *should* be concerned about our imminent toasting.

Allison and I are medievalists, and we re-create costumes and food from across many centuries. England is not as warm now as it was in the 1300s, when tights were in fashion and they grew grapevines there. Then things got very cold again, furs were back in fashion and the food got much heavier.

My university degree had two majors. One was in Psychology, which teaches you lots about statistics, and how we consciously and unconsciously manipulate them in support of certain beliefs and agendas. The other was in the History and Philosophy of Science, which teaches you that science is anything but an abstract mechanistic process. People have often believed crazy things, based on the best evidence, and the few doubters have regularly been shown to be justified.

I follow the scientific argument quite closely, and I’m yet to be convinced that there is any serious warming to worry about, or that CO2 is a significant cause of warming. A good introduction to the discussion is here.

Along with the Medieval Warm Period, and the Viking Warm Period when they colonised Greenland, there are smaller peaks and troughs too. The 1990s were a warm decade, very similar to the 1930s. The world seems to be cooling again in the past five years. Depending on your starting and finishing point, you would either be seriously alarmed or completely underwhelmed — or you could conclude that the earth is cooling rapidly, as they did in the 1970s when I was young. A new ice was imminent.

We had very serious bushfires in Victoria this summer — trumpeted as all the proof you would need that Global Warming is real. At the same time, London was freezing. There have been much bigger fires in Victoria before, but now there are more people living in heavily timbered areas, in big houses with timber decks amongst the beautiful trees. So is it a warming issue or a failure of planning controls?

Recently there was an article in Nature magazine about warming in Antarctica. It was quoted in all the newspapers with a big map showing the continent in red — proof again of Global Warming?

If you read the article carefully, there was a very small warming in western Antarctica, roughly balanced by cooling in the east. And the warming actually happened in the 1950s, with nothing much since then. That’s hard to reconcile with the global warming models.

I have been following this discussion at Climate Audit, a “denialist” website run by a Canadian statistician. It can be rather dry reading, but there are some gems. It turns out that the data for Antarctica is of poor quality, and the weather stations showing the most warming have turned out to be mistakes. Even where the data exists, some weather stations have been covered in snow for months on end, which makes them record warmer temperatures than if they were exposed. There are very few data points, and the methodology for interpolating between sites makes some key assumptions which are nonsense.

The scientific argument is still going, but as far as I can tell most of Antarctica has actually been stable or cooling for decades, perhaps with some minor warming on the peninsula near South America. Even there, it may just be recording heat from the expanding scientific settlements. Nothing to worry about.

Permaculture is quite comfortable with the idea of natural cycles, and we are still overdue for the next ice age. So it may all become a moot point over the next couple of thousand years.

For the record, I am very much in favour of solar power, innovations in batteries, and energy conservation in particular. There are heaps of good reasons to do this stuff, even without worrying about Global Warming. I am somewhat concerned about CO2 increasing seawater acidity, but that’s another issue and I’d love to see more data.

PS – if you’re wondering what’s happening on the property, we have Hanna and Allisa here from Germany, and David and Caroline from France. We have heaps of projects underway, but nothing to show off right now. Our wwoofers finished their work early today, and headed off to Batemans Bay for the beach and some kangaroos to pat.

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