The planet’s fine, save the humans
IT is often quoted that research has discovered that 97% of the world’s eco-scientists believe climate change is both real and man-made. The remaining three per cent believe it is a fiction or that humans have nothing to do with the change in climate.
According to a new paper, published in the journal of Theoretical and Applied Climatology, and which examines papers produced by the three per cent (termed, climate contrarians), it finds flaws in their methods or in assumptions they made to deny man-made climate change.
Be that as it may, it is indisputable that the climate is changing and has been doing so since the planet first formed from the accretion disk around the sun, about 4 500 000 000 years ago. According to astrophysicists and geologists, following the late heavy bombardment period (that ended about 3.9 billion years ago), the Earth’s atmosphere was made up mainly of hydrocarbons such as methane as well as Carbon dioxide. It would have been totally toxic to most life on the planet today, and yet life (albeit bacterial in nature) thrived. It was only after another two billion years, during the period known as the Cambrian Explosion, that life developed into multicellular organisms in our oceans, and a considerable time later before plants appeared on land, and the first creatures crawled from the oceans.
The release of free oxygen was mainly caused by bacteria that expelled it into the atmosphere (this is before trees were able to do the same), and complex life could take hold by adapting to use the oxygen for energy.
The planet itself was also subject to a number of mass extinctions over the last two billion years including asteroid and comet impacts, super volcanic emissions and viral and bacterial infections. It has been a cold planet more often than its climate has been temperate and our current epoch is known as an interglacial period, in other words, a respite between ice ages.
One of the reasons why the Earth is not a “snowball” world at the moment is the quantities of greenhouse gasses in the atmosphere that allows light to penetrate on the way in but trap heat as it attempts to flow out into space. The balance is crucial for a number of reasons.
As the sun’s rays hit land, some are absorbed and others are reflected back where they hit the atmosphere and much is absorbed again. If the sun’s rays hit ice and snow, most are reflected back into the atmosphere. But when the light rays hit the oceans (that cover 70% of the Earth’s surface) they are absorbed. Therefore, if the ice melts, fewer rays are reflected back into the atmosphere, but more land or ocean is revealed, leading to more heat being absorbed and the planet heating up. With a build-up of carbon in the atmosphere, less of the sun’s rays (now heat) are able to escape and the Earth’s atmosphere warms, causing more ice to melt. It’s a vicious cycle and what is termed “runaway greenhouse effect” just means that a tipping-point has been reached that, no matter what we do, the planet will continue to warm up, at least until another tipping point is reached.
We need only look at Venus, whose surface is hot enough to melt lead, to get an idea of a runaway greenhouse effect.
But sometimes global warming can lead to global cooling. For example, the last major ice-age ended about 20 000 years ago, when at the time, New York would have been under a glacier approximately 2km thick. As the glaciers receded they pulled claw marks into the land of what is now North America, creating the Great Lakes. But the ice-cold water found an escape into the North Atlantic Ocean, halting the flow of the Gulf Stream almost instantaneously. Suddenly El Neno stopped in its tracks and the land was no longer being warmed by the oceans. The world went back into a mini-ice-age for another 10 000 years.
So, whether caused by man or not, the global climate (temperature, winds, rains, hurricanes, tornados and so forth) is always changing. But there is a principle here that not everyone appreciates.
Fossil fuels are just the stored carbon from millions of years of forest litter such as leaves and trees and even animals, that have been compressed under the weight of the earth or water above them. In the last 100 or so years, we have probably burned millions of years’ worth of stored carbon, releasing a blanket of carbon into the atmosphere. This most certainly has had an effect on our climate, but the extent of its impact is still in dispute.
Yet the point is that such oil and gas deposits will, one day (and some estimate within the next 50 years) run out. To continue to be totally dependent on a resource that will one day run dry seems like an irrational thing to do. The problem is not just one of finding alternative sources of energy. Already we have photovoltaic cells that can convert sunlight into electricity, and these will become more efficient as technology improves. We have wind farms, and hydroelectric options, we can pull oxygen from water, and we can run our vehicles on hydrogen, but none of these alternatives can exactly match what fossil fuels provide (mainly because our industrialised world was built around using oil as the major fuel source).
One answer could be nuclear, but probably not in fission reactors that produce unwanted highly toxic waste, but in fusion reactors that develop heat from hydrogen fusion, much like the sun.
Whatever way we go, it is important for the survival of the human race to find new sources of energy. And slogans like “save the planet” are a little redundant. The planet will survive at least for another four billion years (unless hit by something very large) until the sun uses up all its fuel and begins to get bigger, and the planet ends up in the suns atmosphere. The slogan should rather read “save the humans”.