ABSTRACT
Climate change imperative Global warming is here. According to the Fourth Assessment of the Intergovernmental Panel on Climate Change (IPCC 2007: 2), “warming of the climate system is unequivocal, as is now evident from observations of increases in average global air and ocean temperatures, widespread melting of snow and ice and rising global average sea level.” Scientific reports since the Fourth Assessment have found that the signs of global warming are accelerating faster than predicted, including melting of Arctic sea-ice, glaciers, and ice sheets. Sea level rise in 2009 was 80 percent greater than predicted by the IPCC just two years before. Over the past 25 years, temperatures have increased at an average rate of 0.19 degrees centigrade per decade (UNSW 2009). A September 2009 conference of climate scientists found that “since the late 1990s, greenhouse gas emissions have increased at close to the most extreme IPCC scenarios” and there is a significant possibility of 4 degrees warming before the end of the century (Science Daily 2009). The scientific consensus, and the assumption of the Kyoto Protocol, is that the avoidance of dangerous climate instability requires that warming be kept below 1.5 degrees centigrade. A higher level of warming portends major regional and local impacts on eco-systems, human settlements, food production, and biodiversity. A revised target of 2 degrees put forth by the US at the December 2009 climate negotiations in Copenhagen triggered intense protests by African NGOs who chanted “Two degrees is suicide!” (COP 15 (2009). The primary anthropogenic contribution to global climate change is the emission of carbon dioxide from the burning of fossil fuels and deforestation. As indicated above, under a business-as-usual scenario with no mitigation of emissions, the IPCC’s Fourth Assessment in 2007 projected an increase of 3.5 degrees centigrade by the end of the century (IPCC 2007). Despite more than a decade of global climate diplomacy, global carbon emissions were 40 percent higher in 2008 than in 1990. Even if emissions were stabilized at the current rate and brought to zero by 2030, just 20 more years of emissions would result in a 25 percent probability that warming will exceed 2 degrees (IPCC 2007). In a 2009 review of the science since the IPCC’s Fourth Assessment (UNSW 2009), an Australian team of climate scientists concluded:
If global warming is to be limited to a maximum of 2 degrees C above preindustrial values, global emissions need to peak between 2015 and 2020 and then decline rapidly. To stabilize climate, a decarbonized global society – with near-zero emissions of CO2 and other long-lived greenhouse gases – needs to be reached well within this century. . . . [E]very year of delayed action increases the chances of exceeding 2°C warming.
