Monday, October 8, 2012

Weather Disasters and Global Warming

Older people enjoy telling the most memorable weather events from their early childhood. My personal favorite is the 1947 snowstorm in central New York which closed school in that Snow Belt for a solid week and drifted our country road shut with drifts well over the height of the plow blades. I personally recall my older uncles telling of the horrific dust bowl days of the 1930s where drought scorched the land, top soil blew away, and where summer heat for several years reached triple digits on multiple days. For this post’s introduction, we will point out that nothing in the 80 intervening years has matched such extended drought and heat, including the drought and heat wave of 2012.

Memorable weather events are embedded within long period conditions of temperature, humidity, air pressure, wind, and precipitation over extensive climate regions. These are sometimes known as weather regimes. Humorously, we may compare weather to climate by contrasting individual crops growing in a large garden with the entire garden itself. Each crop in the garden contributes to the totality of the entire garden much like individual blizzards, drought events, or hurricanes contribute to the totality of regional climate over long time frames.

Modern journalists reporting on unusual or severe weather incidents sometimes conflate weather events with climate change. In particular, many contemporary writers having global warming agendas cannot resist blaming unusual weather events on purported man-induced global warming. Weather events deemed unusual, violent, or destructive, need a cause for their effects. This is especially true if the reporter is motivated by a popular “cause.” Writers of museum display texts sometimes fall prey to this tendency, but we do not demean the wonderful value of quality museum instruction.

Scientists are vulnerable to errors in reasoning as are professionals in every field of knowledge. Many errors of reasoning abound. In the currently popular subject of climate change, we may identify common reasoning fallacies. If A precedes B, then B must have been caused by A: If fossil fuel use increases before global warming occurs, global warming effects result from increased carbon dioxide generated by fossil fuel burning, according to the claim. Another commonly used fallacy is termed “oversimplified cause.” The complexity of weather events is blamed on one cause when multiple causes are needed to explain the phenomenon. The “domino fallacy” asserts a chain of devastating effects flow from one cause without providing supporting evidence.

The welfare of our home on Planet Earth is a cause of monumental importance and enormous human interest. Perceptions of damage to our global abode understandably generate vigorous discussion of effects and causes. The force of public argument generated is understandable. Epic topics like global warming share their level of importance with the fervor of supporting argument. The most effective arguments are needed to support the case, but extravagant potential for faulty reasoning exists.

Judith Curry is an American climatologist and chair of the School of Earth and Atmospheric Sciences at Georgia Institute of Technology. She has stated, “Climatologists should be more transparent with the public and should engage with those skeptical of the scientific consensus on climate change.” Curry details her journey toward a reasoned, well-researched stance casting doubt on the strident positions of advocates of human-caused warming. Here is a statement she provided to a Yale360 Forum on the topic of the links between extreme weather events and global warming:

The substantial interest in attributing extreme weather events to global warming is the perceived need for some sort of disaster to drive public opinion and the political process in the direction of taking action on climate change. However, attempts to attribute individual extreme weather events, or collections of extreme weather events, may be fundamentally ill-posed in the context of the complex climate system, which is characterized by spatiotemporal chaos. There are substantial difficulties and problems associated with attributing changes in the average climate to natural variability versus anthropogenic forcing, which I have argued are oversimplified by the IPCC assessments. Attribution of extreme weather events is further complicated by their dependence on weather regimes and internal multi-decadal oscillations that are poorly simulated by climate models.

I (Curry) am unconvinced by any of the arguments that I have seen that attributes a single extreme weather event, a cluster of extreme weather events, or statistics of extreme weather events to anthropogenic forcing. Improved analysis of extreme weather events requires a substantially improved and longer database of events.

Research on extreme historic weather events provides startling revelations which could refute the modern enthusiasm for the connection between weather disasters and purported anthropogenic global warming. Local newspapers frequently offer lengthy lists of severe local weather events going back decades whenever the news of the most recent disaster is reported. Readers usually cannot recall the events even if they have lived in the area a long time.

With the disclaimer that the following list does not prove anything, the following historic weather events are cited as food for thought. (1) Acts 27 recounts a horrific 14-day storm at sea suffered by the Apostle Paul on one of his missionary journeys. The storm, termed “Euroclydon” in the KJV, caused the destruction of Paul’s ship. It may have rivaled violent hurricanes in the Atlantic and Caribbean. (2) Centuries later the “Great Hurricane of 1780 claimed 25000 lives and was one of three exceptionally strong hurricanes during that decade. (3) The mile-wide tri-state tornado of 1925 claimed 695 lives and ravaged Missouri, Illinois, and Indiana for 3½ hours over a distance of 219 miles, the longest single tornado track on record worldwide. (4) The Mississippi River flood of 1927 was the most destructive river flood in United States history. Each of the events occurred long before climatologists of the last decade began to spread the gospel of anthropogenic weather disasters.

Climate change is generally considered a topic church leaders entrust to the knowledge of science specialists. Some Christian organizations have taken remedial action based on controversial findings. Many other topics of Christian concern are linked to science and to the expertise provided by scientists. Such topics include earth history, evolution (origins), and health to name a few. It is vital that church leaders and laypeople alike be well served by secular science experts. But we must be certain their science interpretations are trustworthy. If climate scientists disagree, laypersons and theologians alike must devote themselves to the discovery of truth. We must wisely care for the marvelous planet God has entrusted to man. Our environmental stewardship is an important part of the outworking of our Christian worldview.