We have spoken repeatedly about the difference between climate science scepticism and climate science denial. Scepticism is at the heart of the scientific enterprise; a sceptical approach to knowledge claims is consistent with the contingent, or provisional, nature of scientific knowledge.
Climate scientists are themselves sceptical about climate science in that they know that while they have learned a great deal about how our climate works, there is much that is either unknown or that can be known better. With that in mind, I provide for your enlightenment a skceptic’s guide to climate science published by the Berkeleyearth.org. It’s interesting that the Professor of Physics Richard Muller, the founder and scientific director, is a self-admitted ‘converted sceptic’. Indeed, he once believed that the gaps in the scientific knowledge of climate change were so large that he doubted the very existence of global warming. In this op-ed in the New York Times, Muller writes:
Three years ago I identified problems in previous climate studies that, in my mind, threw doubt on the very existence of global warming. Last year, following an intensive research effort involving a dozen scientists, I concluded that global warming was real and that the prior estimates of the rate of warming were correct. I’m now going a step further: Humans are almost entirely the cause.
My total turnaround, in such a short time, is the result of careful and objective analysis by the Berkeley Earth Surface Temperature project, which I founded with my daughter Elizabeth. Our results show that the average temperature of the earth’s land has risen by two and a half degrees Fahrenheit over the past 250 years, including an increase of one and a half degrees over the most recent 50 years. Moreover, it appears likely that essentially all of this increase results from the human emission of greenhouse gases.
These findings are stronger than those of the Intergovernmental Panel on Climate Change, the United Nations group that defines the scientific and diplomatic consensus on global warming.
Although there is strong scientific evidence of human-induced global warming, there are still many issues that are scientifically not settled. Read the following short, but instructive document to learn how to become an informed climate science sceptic. The alternative is to look as uninformed as this guy:
In intro to comparative, we have generally compared spatially across countries (or states). There is a lot of explanatory power, however, that can be achieved by modeling and comparing political phenomena at the sub-national level. Maximilian Auffhammer and Richard Carson–two economists–have done this by modeling the rise in Chinese CO2 emissions, using a panel data set at the provincial level in China. Their data set includes 30 provincial-level entities (or provinces) analyzed between 1985 and 2004. See a post I made on China’s pollution problems and economic growth here. I’ve reproduced a slide show from the post below. Here’s a snippet from their paper, which can be accessed here:
The People’s Republic of China (PRC) has long been seen as the key future participant to an effective agreement limiting the adverse impacts of climate change. It is currently the number two emitter of carbon dioxide (CO2) and is about to overtake the United States, who has held this position since 1890, as the leading emitter. Further, the United States has long preconditioned its adherence to any international agreement such as the Kyoto Protocol on China’s formal concurrence that it would also undertake substantial CO2 reductions. Efforts to reach such an agreement failed in the late 1990’s during the Clinton administration and the Bush administration decided not to pursue policies that would allow it to sign the treaty and have it rati¯ed by the U.S. Senate.
This paper presents econometric forecasts that strongly suggest that the short to medium term path of Chinese CO2 emissions has increased by a factor of two or more since that time. Our best forecast has China’s CO2 emissions surpassing the United States before the year 2010 rather than 2020 as previously anticipated (Intergovernmental Panel on Climate Change, 2000; Siddiqi, Streets, Wu and He, 1994; Panayotou, Sachs and Zwane, 2002). Our focus in this paper is on exploring alternative econometric specifications for forecasting China’s CO2 emissions using a rich new panel dataset from 1985 to 2004 at the provincial level. The prediction of a dramatic recent increase in the predicted path of China’s CO2 emissions over the short to medium term horizon is shown to be robust to a wide range of alternative specifications. We show, however, that it is possible to strongly reject both the standard engineering specifications that appear in the Intergovernmental Panel on Climate Change (2000), and the recent Stern Report (2006) as well as the popular environmental Kuznets curve specification. All of the “best” models are dynamic in nature employing some type of lag structure, which is consistent with the nature of an installed durable capital stock.