There is no quick fix to the CO2 emission crisis, laments Leonie Joubert. Worse still, today’s emissions will only manifest in a generation from now.
This is an imaginary experiment. It’s all made up, but its outcome illustrates why the climate change meeting that took place in Bali last month was critical to the future of life as we know it.
Pop two saucepans on the stovetop. Fill one with seawater (one litre), another with air (one litre) and seal them up. Now add heat and watch the thermometers.
What you can expect is that the air will heat up faster than the water. It is simple physics – liquid is more dense than air so needs more energy to heat to the same temperature. This explains why climate change scientists refer to the “lag” in the ocean-atmospheric system.
This is how it works: once a molecule of greenhouse gas (GHG), let’s say carbon dioxide (CO2), is released into the atmosphere, together with the other accumulated GHGs, it will begin to trap heat from the sun and warm up the air. Because the ocean-atmospheric system is intertwined and equally responsible for the planet’s climate, the ocean then begins to absorb that heat but the process takes longer for the ocean to warm up. Only much later, as a result, will this warming begin to show itself in altered climatic patterns.
This lag means that no matter what gets implemented after Bali – even if, by some miracle of human ingenuity, we were able to halt all GHG emissions today – we would still be committed to a certain amount of climatic change.
The bottom line is this: the emissions put out before you and I were born are only now beginning to cause glaciers to drip faster and storms to be more potent. Those emissions put out during the past decade will only manifest once we’re well into our retirement or beyond.
Word coming out of the United National Climate Change Conference in Bali this past December is that we have a ten-year window of opportunity in which to level off our greenhouse gas emissions, if we want to avoid an average temperature increase above 2°C. Because of the accumulated GHGs already in the atmosphere – those added to the naturally occurring GHGs – we are already committed to an increase of no less that 2°C.
The level of CO2 in our atmosphere now is the highest it has been in the past 650 000 years and since 1750, the start of the industrial revolution, CO2 has climbed by 36 percent. Measured in “parts per million” or PPM, its concentration has climbed by 100 PPM during that time.
Alarmingly, though, the rate of increase is speeding up. It took 200 years for CO2 to rise by the first 50 PPM, but only 30 years to rise by that same amount again. If we continue business as usual, says British economist Sir Nicholas Stern, we will drive GHG concentrations to three times the pre-industrial level by the close of this century, “committing the world to 3°C to 10°C warming”.