/ 22 April 2013

Happy Earth Day – from a not so happy earth

Happy Earth Day From A Not So Happy Earth

Without being too alarmist, human life impacting earth is a key discussion that needs to be resolved before things change too quickly and by too much. Then international action can be done to lower greenhouse gas emission, rather than the piecemeal country-by-country method being used now.

It is not that the planet has ever been in good health. It has always suffered extremes, swinging from great warmth to ice ages. Dotted between these have been nice, calm, ages where life has managed to eke out a niche.

This is one of those ages. For the last 10 000 years things have been at just the right temperature to allow agriculture to flourish. This mass production meant people were freed-up to sit about and ponder the meaning of life and make everything more "civilised". Before that there were 100 000 years of ice age.

But this led to industrialisation and humans pumping out vast quantities of greenhouse gases in order to sit on a couch and watch people live lives on television.

The people who argue that this has not impacted the planet play clever games with numbers. They point out that the planet naturally produces 800-billion tonnes of greenhouse gas a year. Humans produce a seemingly paltry 20-billion tonnes.

But the planet naturally absorbs and deals with this 800-billion, through systems such as forests. That 20-billion is therefore extra gas and forms a layer in the atmosphere, trapping heat and warming the planet.

Think of this like the national speed limit. Travelling at 120km/h you are fine. But if you go over this, even by a little bit, you are breaking the law and liable to a hefty fine. This extra heat that is bounced back is leading to quite profound changes.

Too much heat
The enemy of planetary equilibrium is heat, stored as energy. Too much of this and everything goes out of kilter and the planet has to struggle to make things calm again.

The biggest storage place for heat is in the oceans, and with their size they are very slow to change their overall temperature. As a result they tend to create some uniformity across the planet. But as more and more heat is added to them, they warm up. As the rate of this warming increases, the impact increases.

In South Africa this is problematic because so much of the climate is determined by the ocean's Agulhas and Benguela currents. These currently make it warm and wetter on the eastern side, and colder and drier on the west.

With these starting to change the projections are that the north-east will get wetter, and everywhere else will get drier. The rain that does come will be in shorter, more violent spells. This is not good for anyone trying to grow anything, where consistent rainfall is key.

This will have the biggest impact for the poorest. Subsistence farmers are now starting to find that their age-old planting schedules no longer work and that their strain of crop is not able to come to full size over a season.

For the larger farmers and the economy as a whole it means great threats to food security. In some seasons South Africa already has to import some of its food. With recent crop failures in the United States and Russia – thanks to increasing droughts – this has driven prices up.

High prices again mean the poor are disproportionately affected and revolutions have always come about when people are no longer able to afford basic food – think, the French Revolution.

So the earth is doing even less well than it has ever done and those who are having the least impact on driving this change will be the ones who suffer the most.