In his Weekly Address titled “Confronting the Growing Threat of Climate Change” on June 29, 2013, President Obama said,
“And while we know no single weather event is caused solely by climate change, we also know that in a world that’s getting warmer than it used to be, all weather events are affected by it – more extreme droughts, floods, wildfires, and hurricanes.”
Why does Obama spread fear and misinformation while proposing drastic policy initiatives costing hundreds of billions of dollars, all the while relying on false statements that are directly contradicted by the science?
Let’s take them one at a time. (Findings from IPCC AR5 listed as quotations in bullet points below.)
More Extreme Droughts?
Source: Hao et al. 2014, Scientific Data, http://www.nature.com/articles/sdata20141
- “There is low confidence in a global-scale observed trend in drought or dryness (lack of rainfall)…”
- “…the frequency and intensity of drought have likely increased in the Mediterranean and West Africa and likely decreased in central North America and northwest Australia since 1950.”
- “There is high confidence for droughts during the last millennium of greater magnitude and longer duration than those observed since the beginning of the 20th century in many regions.”
More Extreme Floods?
- “There continues to be a lack of evidence and thus low confidence regarding the sign of trend in the magnitude and/or frequency of floods on a global scale over the instrumental record.”
- “Low confidence that anthropogenic warming has affected the magnitude or frequency of floods at a global scale.”
More Extreme Wildfires?
Global data on wildfires is hard to come by, and IPCC AR5 says nothing that I could find about global attribution of more extreme wildfires to anthropogenic warming, although it does discuss various regional areas, some of which have increased and others of which have decreased due to a large variety of factors.
The US Department of Agriculture (USDA) Forest Service and the Environmental Protection agency do have some data on wildfires in the USA. USDA publishes the graph below on its page about Area and percent of forest affected by abiotic agents where it notes, “Between 1945 and 2000, fire suppression substantially reduced annual acreage burned. Since 2000, an increase in area burned has occurred, although it has not yet reached the levels recorded between 1925 and 1960.”
Note: The USDA chart data ends at 2007. I appended data from the Environmental Protection Agency Wildfires page Figure 2 for the years 2008 through 2014. Since reaching the 20th-century low point in 1987 of 2.1 million acres, the 5-year average peaked in 2008 at 8.3 million acres and has declined to 5.9 million acres as of 2014, approximately where it was in 1960.
*I added extension data at right from Figure 2 on EPA website here
More Extreme Hurricanes (aka tropical cyclones)?
- “It is likely that the global frequency of tropical cyclones will either decrease or remain essentially unchanged.”
- “Low confidence in attribution of any detectable changes in tropical cyclone activity to anthropogenic influences”