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How humans are geo-engineering the planet

”    .Aren’t we too puny rival the great forces of nature that shape our planet? .

But the facts show that we are fundamentally impacting planet Earth in unprecedented ways, and we’ve known about it for a century.

Measuring our impact

So what are those measures of our geological impact, and how do they compare to the natural energy and material fluxes that shape our planet?……….in an extraordinary demonstration of our geological power, the proposed Olympic Dam [uranium mine in Australia] open cut development plans to extract about 14 billion tonnes of rock over a 40-year period.With peak extraction rates of about 400 million tonnes a year, it would excavate enough rock over its life to cover metropolitan Melbourne four metres deep.

That’s a lot of rock, even by geological standards.

The rate heat is released from the earth – a measure of its natural “metabolic rate” – is well understood. It’s about 44 trillion watts, and reflects the average rate of energy transferred in moving all the continents, making all the mountains, the earthquakes and the volcanoes on our planet in a process we call plate tectonics.

By way of contrast, the International Energy Agency estimates our human “energy system” operates at a rate of some 16 trillion watts.

So we are already operating at one-third the rate of plate tectonics, and with our energy use doubling every 34 years we are on course to surpass plate tectonics by about 2060.

Climate scientists talk about the climate sensitivity in terms of a “radiative forcing” – an obscure term that accounts for the rate of heat energy gain or loss due to a change in a climate parameter.

The radiative forcing of a doubling of CO2 is about 1300 trillion watts – or 28 times the energy released by plate tectonics.

And we are well on the way to doubling CO2. In the past 100 years we have added almost 40 per cent, and warming that can only plausibly be attributed to a greenhouse effect is not only heating the atmosphere, but is also pumping heat into the oceans and the crust at a phenomenal rate.

The scale of our energy use is truly mind-boggling. In fact, the sheer size of these numbers makes it difficult for most people to grasp and comprehend their significance; few of us have any useful reference frame for comparison.

A new measure of energy use

To put these numbers into a more human context we need a a new measure for our energy use. The “Hiro” is one. It is the equivalent to the energy released by detonating one Hiroshima “Little Boy” bomb every second. One Hiro equals 60 trillion watts.

In these terms, our human energy system operates at a rate of 0.25 Hiros, or one Hiroshima bomb every four seconds. That is the equivalent of more than eight million Hiroshima bombs going off each year.

And we are on a trajectory towards the one Hiro mark by 2100, equivalent to the energy release of one bomb each year for every five-square kilometre patch of land on the planet.

The ocean heating is at 5 Hiros over the last few decades – the energy equivalent of detonating more than a 150 million Hiroshima bombs in our oceans each year.

And the radiative forcing of the CO2 we have already put in the atmosphere in the last century is a staggering 13 Hiros. The equivalent in energy terms to almost half a billion Hiroshima bombs each year…….

We are indeed a geological agent of unprecedented power.

Whether we like it or not, for better or for worse, we are already engineering our planet…….

Faced with that stark reality now, it would be folly at best to maintain the fiction that we are too puny to impact the planet – at worst, it is just plain reckless.

http://www.climatespectator.com.au/commentary/how-were-geo-engineering-planet

June 16, 2011 - Posted by Christina Macpherson | 2 WORLD, climate change