Extreme Weather Events: Are they Influenced by Rising Atmospheric CO2?
3. Extreme Weather Observations and Trends
Numerous studies have been conducted over the past decade or so that allow evaluation of the claim that CO2-induced global warming is increasing both the frequency and intensity of various types of extreme weather events. A recent report by the Nongovernmental International Panel on Climate Change (NIPCC), for example, highlights the findings of over 1,000 scientific papers that have examined this assertion (Idso et al., 2013). That report concludes there is nothing unusual, unnatural, or unprecedented about extreme weather events of the past few decades, and that the ongoing rise in the atmosphere's CO2 concentration is having no measurable influence on these phenomena. A similar conclusion is reached here.
The subsections below highlight the findings of several scientific investigations into three of the most often examined types of extreme weather events: floods, droughts, and storms. Collectively, these studies demonstrate the importance of following the three steps outlined in Figure 2, and correctly navigating the flow chart of procedures presented in Figure 3, in order to properly test for a CO2-induced influence on these extreme weather events. For those desiring additional evidence that anthropogenic CO2 emissions are having a negligible impact on extreme weather beyond the three event categories examined here, please see the Extreme Weather chapter from the aforementioned NIPCC report that can be downloaded at http://www.nipccreport.org/reports/ccr2a/pdf/Chapter-7-Extreme-Weather.pdf.
3.1.1 Trends of the Past Century
3.1.2. Natural Variability Seen from Long-term, Centennial-scale Studies
3.1.3. Other Factors Driving Observed Trends
3.2.1. Trends of the Past Century
3.2.2. Natural Variability Seen from Long-term, Centennial-scale Studies
3.2.3. Other Factors Driving Observed Trends