December 11, 2008

Paleostorms of Southern France

Filed under: Climate Extremes

The United Nations Climate Change Conference is well-underway in Europe and environmental groups are lobbying to reinforce every pillar of the greenhouse gas – global warming story. According to their reports, any severe storm any place on the planet can now blamed on global warming. Thunderstorms, tornadoes, hurricanes, winter storms – it just doesn’t matter … they are all caused by global warming and any deaths or damages from these storms is directly related to the consumption of fossil fuels, particularly that obscene consumption in the United States. Of course, they always insist that the debate on any of these subjects is over, and it is now time for action. Even U.N. Secretary-General Ban Ki-moon told the conference participants, “The economic crisis is serious; yet when it comes to climate change, the stakes are far higher…The climate crisis affects our potential prosperity and our people’s lives, both now and far into the future…we must recommit ourselves to the urgency of our cause.” Damn the torpedoes, full speed ahead!

Well, before you get carried away and win a Nobel Peace Prize, be alert that we have covered this nonsense many times in the past at World Climate Report, and the scientific literature on the subject continues to provide a stream of evidence countering the claims of the global warming advocates. As we have seen many times before, the claims of increasing storm intensity or frequency are generally inconsistent with the conclusions of the United Nations Intergovernmental Panel on Climate Change (IPCC) and certainly at odds with dozens of articles published each year in the professional scientific literature.

The latest piece appears in Marine Geology which may seem strange given our focus on severe storms in the atmosphere. However, large storms in coastal areas leave behind a signal in the sediments that can reveal the time and strength of severe storms in the past. The latest article takes us to Europe (southern France) where conditions are nearly perfect for detecting big storms of that may have occurred hundreds of years ago.

Eight scientists from four major institutions throughout France note that “Storms are one of the most alarming natural hazard due to the recent concentration of resources and population in coastal areas. In view of the last winter storm events having affected the south of France like in 1982 with 46 m/s wind (category 2 in Saffir–Simpson scale), this storm caused the death of 15 people and economic losses estimated at 400 million euros.” They note that “It is necessary to examine the past decadal- to millennial-scale variability of storm activity in order to determine the frequency of the most extreme events in relation to the climate evolution. General circulation models have been used to investigate the variations of the cyclonic activity in the Mediterranean region.” In some cases, the results “clearly show a decrease of the frequency and an increase of intensity of the severe cyclones for the future (2071–2100).” Other results “do not show a large change in the regime of the cyclone in the same region in relation to the doubling of the CO2 atmospheric content. Both models, based on meteorological data, do not give the same conclusion.” Once again we see a debate in the climate change world that according to many doesn’t exist anywhere in the climate change issue.

Sabatier et al. note that “In north-western part of the Mediterranean Sea instrumental records are only available since the last 20 yr for surge and waves (wave buoy in Sète) and 50 yr for wind speed and direction (meteorological station), we used sediment cores to record the past washover events.” The research team located the Pierre Blanche lagoon which “is an elongated lagoon, 267 ha large and 60 cm water deep. Its northern part is limited by the Rhône-Sète navigation channel (construction started in 1666). The south-east boundary is a 5 km long and ~200m wide sandy barrier. Even if there is no direct connection with the sea, in some places the barrier is less than 60 m wide and 3 m high above the mean sea level. This implies a strong marine influence during storm events, as evidenced by the traces of ancient inlets.” Basically, any big storm in the area will force sediments into the lagoon that can be analyzed to provide information on past severe storms. Not too surprisingly, big storms will deposit marine species into the lagoon, but during long periods without large storms, lagoonal species will dominate the sediments.

The graphic below (Figure 1) shows the results from their thorough analyses of the sediments from the Pierre Blanche lagoon. The research team found “In the last 400 yr, the stronger storm occurred in south of France was in 1666, 1669, 1738, 1742, 1766, 1771, 1790, 1839, 1893, 1956 (historical account) and 1982, 1999 (MétéoFrance data). In communal account, storm events were mentioned because they make damage in the vicinity of the studied city. Sedimentological and paleoecological results described above allow us to identify the most powerful storm events as historical period (i.e. paleostorm) with the presence of sand layer (50–150 μm) together with marine species (B. reticulatum) and the disappearance of lagoonal species. Based on our age model the last three catastrophic storm events recorded in this cores-transect occurred in 1742 (with the inlet closing in 1761), 1839, and 1893.” Very interesting (keep in mind, English is their second language – imagine if we had to write this essay in French) – the most severe storms all occurred before 1900, and long before the buildup of greenhouse gases.


Figure 1. Storm event characterization in core PRO 15. From left to right: 210Pbex and 137Cs activity-depth profiles, 14C date (grey band), sediment description, 50–150 μm grain size population, lagoonal species (Hydrobia acuta). Dotted bands correspond to the main paleostorms events registered in historical accounts (from Sabatier et al., 2008).

With respect to the recent storm in 1982, Sabatier et al. state “It should be noted that the most recent catastrophic event, the 1982 storm, was not registered in the studied sediment cores. One could argue that the storm events described above were of similar intensity as the 1982 event, and that they were recorded in the lagoon sediments because of a thinner barrier in the past centuries. However, examination of old geographical maps shows that the location and width of the barrier have not changed significantly. It thus appears that the past storm events registered in our cores were stronger than the 1982 event.”

Once again, no evidence is found of any increase in the frequency or intensity of storms, and in fact, the large storms of southern France seemed more frequent more than 100 years ago. These authors are in the neighborhood of the United Nations Climate Change conference, but we suspect their recent findings will make no impact whatsoever to the never-ending claim that severe storms are increasing in frequency throughout the world.

Reference:

Sabatier, P., L. Dezileau, M. Condomines, L. Briqueu, C. Colin, F. Bouchette, M. Le Duff, and P. Blanchemanche. 2008. Reconstruction of paleostorm events in a coastal lagoon (Hérault, South of France). Marine Geology, 251, 224–232.




No Comments

No comments yet.

RSS feed for comments on this post.

Sorry, the comment form is closed at this time.

Powered by WordPress