Thursday, February 05, 2009

The Bump and Grind of Mother Nature

Sometimes, Mother Nature can be a real bitch. Other times, she’s the best!

We’ve been riding a rollercoaster of weather all year. Yesterday and today we sunk to deep freezes of -20C wind chills, and they are predicting potential record highs of +6C on the weekend.

What gives?

Welcome to a whole new world order – thanks to global warming. Since the last ice age, our planet has been increasing in temperature, that’s natural. But since people have walked the earth, our planet’s average temperature increases have been quicker, in part due to our extensive use of fossil fuels.

Since scientists have been tracking this global phenomenon, our human-kind has had about a one-degree-Celsius increase per year. That might not seem like much – it is barely noticeable to us in our nice and toasty environment-proof homes.

But with every additional degree major natural meltdowns occur – some quite literally meltdowns. The polar ice caps at both ends of our planet have – and continue to – shrink in terms of physical mass. All this melting causes the earth’s oceans and other water bodies to rise.

And, believe it or not, the increase in frigid water in our oceans, lakes, and streams is why Mother Nature has been taking us on a bump and grind ride for quite some time.

Our weather is deeply affected by something scientists call the Thermohaline Circulation (THC) of our oceans. The THC is essentially this big ocean conveyor belt, constantly churning cold air from the polar regions through the warmer tropical-based waters.

At about ten-centimetres-per-second, this conveyor of oceanic currents isn’t going to win any races – but because it spans the entire world, it carries the equivalent of 100 Amazon rivers worth of water per second – that’s about 30-million cubic meters per second!

Warm Surface waters are carried in this great conveyor to higher levels in the oceans, releasing this heat into our atmosphere. This causes the water to cool and eventually to fall back to earth as rain, snow, fog and other forms of precipitation. Cooler water is heavier and sinks to the deepest levels of the earth’s oceans, which is carried via tides, around the globe, rising slowly as it warms, until it again is warm enough to enter our atmosphere. The whole cycle can take as long as a thousand years, but because the age of the earth is well beyond that thousand years, the movement of waters is constant.

Cooler, denser water has more salt, and from scientific computer models, we now know Mother Nature doesn’t like too much salt. See, the cooler, saltier waters should ideally be at the deepest levels – towards the bottom – of our oceans. But scientists have found over the past 40-years, an increase of fresh water in these areas (such as the North Atlantic). As warmer fresh water replaces much of the cooler saltier waters, this great big conveyor slows down. Some scientists are even concerned it may stop completely.

As the changes in the conveyor continue, we feel it globally. We see more wild weather patterns, like the massive hurricanes we’ve seen in recent years, such as Hurricane Katrina, and we see more uneven weather patterns, like we are experiencing now.

All it will take is a mere five-degrees-Celsius decrease in oceanic temperatures to cause enough of a slowdown in the great conveyor of water, to create another ice age, according to scientific research and historical data about the climate from our last ice age.

So what’s this all mean?

It may be annoying going from one extreme weather event to another, but these are far more serious indicators of where we may end up.

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