Saturday, February 7, 2009

With a new record temperature in Melbourne (Australia) set this month, there will be, without doubt, cries that global warming is to blame. But is it?

On the other side of the world, England has been hit by a severe cold front, disrupting life for millions. But nobody there is blaming global warming. But they've had worse winters, for snow, than this year. How do we know that there hasn't been similarly hot (or hotter) weather in the "Melbourne" part of the world before?

A big problem that Melbourne faces is that it is one great big Urban Heat Island - especially in areas of new development. Footpaths with trees that can grow up and provide a canopy to the road in later years is essential. A good way to grasp the problem here is to take a walk in a wooded area on a hot day and compare that with walking by a road. Compare the temperature of the ground, not just during the day, but after night fall, when black ashphalt can still be releasing significant amounts of heat. The contention here being, to what extent would the construction of cities made from steel, concrete and ashphalt make on the environment even if there were no people or fossil fuel burning?

But is it fair to blame a temperature of 46.4C on global warming? Hardly. The earth is 100s of millions of years old. We have accurate weather data for maybe 100 years. What we can say is that putting more carbon dioxide in the air is bad (because it must mean that there is less oxygen) and we can say that on average, there has been a small rise in average temperature over that time.

But consider the Earth's history. It has descended into ice ages and come out of them without man to either help or instigate them. So there must be clearly something else going on. Our problem is that we do not have any accurate data to know what happened before these events that brought them on.

While global warming is something we need to face up to, what are we (the human race), going to do when the next ice age comes around? I say when and not if because they do occur on a regular basis. How will we deal with North America being under half a mile of snow and ice? Where will 300+ million people go? Will they just die? And what of Europe and Asia? And what if global warming is the only way to avoid another ice age? I suspect that may be a foolish statement and that either the progression to ice age is cyclical (and we will end up in another one, regardless of what we do or do't do, just as the tide always goes in and out) or we'll manage to change the cycle to be something else. Whilst some dooomsday folk would like to pretend that we'll cook the planet, I don't believe that will happen. What will happen is that we'll change the points between which the planet's weather oscillates. For example, last year, many places on Earth recorded much lower temperatures than average: Temperature Monitors Report Widescale Global Cooling.

While we can say that there has been a gradual rise in the average temperature over the last n years, how do we know that has not happened before in the history of the planet? And how do we know it will continue? In short, we don't. And perhaps our greatest folly is pretending that the world will always be as it is now. That it won't change. That the weather won't change. That another big chunk of rock from space won't land on our back door step. In our ascendency here on Earth, we've become masters of many aspects of this planet but we aren't (yet!) masters of its weather or tectonics (and will likely never be.)

If the Earth has swung into being very cold as recent as 15,000 years ago, how do we know it hasn't swung to being much warmer, before, than the average we've calculated over the last 100 years?

But consider this: in our continued burning of fossil fuels, each year we release into the Earth's environment extra energy. That energy doesn't all just evaporate out into space, it hangs around, warming the planet. Thus to solve global warming, we need to find a way to take that energy out of the atmosphere and return it to the ground. The only option we have here might be to just start planting more trees. In the mean time, using energy sources such as the wind and sunshine will help move our energy use away from tapping the bank of stored potential energy. The green reader might notice that I left out geothermal from that. I've also left out microwaving energy to Earth from orbit for the same reason: while both are "green", both introduce more energy into the biosphere than what brought us to our position of content - the continual bombardment of our planet with energy from the Sun.

All of this isn't to say that we shouldn't stop polluting the atmosphere: we should! In our thirst for money and power, we're stripping forests away at an alarming rate, largely in impoverished areas like the Amazon jungles of Brazil where it is hard to make a living otherwise. In doing so, we're reducing the capacity of the planet to make oxygen (which we need to live) and increasing the amount of carbon dioxide (which is not so healthy for us.) A similar problem exists for cars: they consume oxygen and produce carbon dioxide, not to forget using up our finite supply of fossil fuel. We're cutting off our noses to spite our faces.

The problem we face is two fold: (1) the current level of pollution is higher than we believe it has ever been for the planet and (2) there is no sign yet of the human race's activity abating. So while some might be tempted to say that even at current levels we're all surviving on this planet, so things can't be that bad and therefore we don't need to do anything to change, where we're we at is not the end game and the real problem is, we don't know what the end game will be or what it will look like.

p.s. If you're wondering what the point of this all is, it is to consider that we really have a paucity of data available on the environment (when you consider its age) with which to make predictions for the future. In places on Earth that have dynamic weather patterns (such as Melbourne), the Bureau of Meterology considers a successful forecast to be if their forecast for the day from 5am is close to accurate. That's a forecast for the next 18 hours. 5 day forecasts are notoriously unreliable. But yet people are trying to claim that models for the climate (due to global warming) can predict what the world will be like n years from now. Who's to say that the macro weather patterns aren't just as dynamic as the micro weather patterns?

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