Climate Realism previously discussed this very same issue in the Volta River Delta of Ghana, here, where major issues with land subsidence in Ghana’s coastline accelerated after dams were built upstream in the Volta river.Īnother factor widely recognized as contributing to the erosion of Louisiana’s coast has been the introduction of the voracious South American transplant, the rodent nutria. In addition, like other river deltas, Louisiana’s coast has low elevation, extended floodplains, and is prone to erosion and land sublimation, especially since the regular addition of sediment, delivered by the Mississippi annually to the marsh area has been prevented to control flooding and help shipping. Coastal development and channels dredged through the coastal wetlands are likely culprits contributing to the declining barrier marshlands. The comment from the article related to islands “starved” of sediment due to civil engineering projects controlling the Mississippi flood plains and movement may very well be part of the problem, but that’s not climate change. The Louisiana coast is not like the long stretches of beaches that you find in parts of Texas and much of Florida as a river delta environment, it is shaped largely by the Mississippi river dumping sediment and moving water. Every tidal cycle changes the shape of the thousands of small islands and estuaries. Regardless of human activity, the Louisiana coastline has long been a highly dynamic environment. In fact, Grand Isle has the highest rate of “sea level rise”-most likely due to sublimation-in the continental United states, according to National Oceanographic and Atmospheric Administration data. (Figure 2)įigure 2 Chart from National Oceanic and Atmospheric Administration’s tides and currents dataset, found at Pensacola Florida, however, just a few hours’ drive away from Grand Isle, shows a much smaller rise of only 2.59 mm per year. (See Figure 1 below) Figure 1 Chart from National Oceanic and Atmospheric Administration’s tides and currents dataset, found at
![intensity level intensity level](https://i.ytimg.com/vi/t1yALQ2QGIM/hqdefault.jpg)
Regionally, tide gauge data in Grand Isle, LA, show a relatively fast rate of sea level rise, at just over 9 mm per year. Climate at a Glance: Sea Level Rise, presents data demonstrating that the one-foot-per-century rate of rise has been relatively consistent since the mid-19th century. The rate and direction of sea level change varies by region, and while the overall global trend is towards rising sea levels, the rate is within the historical natural range experienced by the earth since it exited the last glacial period more than 12,000 years ago. Indeed some research even suggests that the number of yearly tropical cyclones may actually be decreasing over time. Hurricane data show that there has been no statistically measurable increase hurricane frequency or severity over the past half century. The article, “ Climate change, vanishing islands in Louisiana threaten brown pelicans,” written by AP reporter Christina Larson says that 12 years ago there were 15 small, low-lying islands that were home to nesting populations of brown pelicans, but now “only about six islands in southeastern Louisiana harbor brown pelican nests - the rest have disappeared underwater.”Ĭlimate Realism has refuted the oft-repeated claims that tropical storms and hurricanes are getting more severe dozens of times, here, here, and here, for example. Coastal erosion is a natural process, arguably exacerbated by human development along the coast. In addition, sea level rise is within the natural rate of rise it has been since exit from the last ice age.
![intensity level intensity level](https://pics.me.me/intensity-level-terry-crews-28112412.png)
Data refute the claim that tropical storms are becoming more frequent or intense. The AP article claims increases in storm frequency and intensity, sea level rise, and resultant erosion of barrier islands along the Louisiana coast, is threatening the habitat of the marine bird. Evidence suggests this claim is likely false. An article by an Associated Press (AP) reporter picked up by the Chicago Sun Times claims that climate change is threatening brown pelicans in Louisiana.