The Kyoto Protocol caused a stir because it committed the countries that ratified it to reducing their greenhouse gas emissions by 5% under 1990 levels by 2012, a target that raised the hackles of many a fossil fuel industry. Now climatologists are saying that we are on the brink of irreversible, runaway climate change and the only way to prevent it is to reduce greenhouse gas emissions to zero as soon as possible. So what science informs this claim?
The Copenhagen Accord encourages countries to constrain global warming to 2 degrees Celsius above pre-Industrial levels. This will work toward preventing or at least delaying tipping points for the planet’s future. The German Advisory Council on Global Change has calculated that for the Earth to have even a 67% chance of keeping global warming below this 2°, it will be necessary for the USA to reduce their emissions to zero in just ten years. In light of Australia’s similar per capita emission rates, it follows that we too must stop emitting, and quick.
Prior to the Industrial Revolution and the rampant burning of fossil fuels that ensued, carbon dioxide levels lay at an estimated 280ppm. CO2 levels currently lie at 387ppm. The scientific consensus is that until industrial activity ceases to emit greenhouse gases altogether, global temperatures will continue to rise. Basically Earth’s carbon sinks simply cannot handle atmospheric carbon content over 300ppm at most; so as long as carbon levels are above this level, global warming will continue. Carbon sinks are sources that absorb carbon dioxide from the atmosphere. They currently absorb about 50% of atmospheric carbon. The ocean is the world’s greatest carbon sink, followed by forests.
Ironically, as the planet warms, carbon sinks are set to become carbon sources. Warmer water in the ocean is less able to absorb carbon than cold; furthermore warmer water compromises the role of phytoplankton in absorbing CO2. Rising temperatures also increase forest fires, which release massive amounts of CO2 into the atmosphere.
To give our planet the best chance at avoiding runaway climate change, it is crucial that we cut our emissions to zero as soon as possible. Beyond Zero Emissions has developed an award-winning Zero Carbon Plan to get Australia completely off fossil fuels by 2020. There is an affordable, commercially available alternative to a carbon economy right now.
Script for Beyond Zero Radio (Mondays 5-6pm), 3CR 855AM