As the dreaded hurricane season starts to ramp up, many wonder what kind of impact a perfect storm might have upon the BP oil spill in the Gulf of Mexico. The first hurricane of the Atlantic season, "Alex", just recently pushed oil onto Gulf coast beaches. To the dismay of local residents, some tar balls were as large as apples. Though Alex has now cooled off, ridiculously warm oceans and still-air mean that storms like "Bonnie", "Colin" and "Danielle" could continue to plague the Gulf.
While future storms might mix up and disperse water and oil, which would in turn make it easier for bacteria to break down and consume larger clumps, hurricanes could also push the BP spill westward into marshlands. Indeed, by their very nature hurricanes move counter-clockwise and as a result will tend to move oil from east to west (up to now, the BP spill has generally been moving from west to east). What's more, hurricanes could complicate any relief effort since they give rise to storm surges, elevated water levels and big storm waves. Those waves spell danger since they reach farther inland as they crash onto beaches. As a result, oil could be spread over a much wider area.
Coupled with the threat of hurricane season, the environmental challenges posed by the BP spill are certainly immense. Yet, difficult as it may seem, we must think about what this environmental crisis means in a longer-term sense and how the Gulf tragedy relates to climate change. While many are aware that the oil industry -- which feeds our cars and spills petroleum into pristine ecosystems -- exacerbates global warming through its carbon emissions, few can say how, exactly, fossil fuels wind up altering the weather. When we look at the wider picture, we must closely consider the "El Niño cycle".
A meteorological phenomenon associated with the Pacific Ocean, El Niño typically crops up every three to seven years and wreaks havoc on the weather. The result of unusual warming in the eastern Pacific, El Niño gives rise to storms, droughts and other weather disturbances. As it slams into South America, El Niño typically results in flooding in coastal Peru and drought in the Amazon. As I discovered in the course of researching my book, El Niño drought has disrupted life for indigenous peoples and others who depend on the rainforest for survival. El Niño has occurred from time immemorial, but here's the catch: Scientists have grown concerned that global warming and our addiction to fossil fuels could be making the meteorological phenomenon more frequent and more intense.
If there is one silver lining in terms of El Niño, however, it is that normally the cycle spurs increases in wind shear (i.e., the difference in wind strength at low levels in comparison to higher level winds) across the tropical North Atlantic. Strong wind shears reduce hurricanes as they break up storms' ability to rise into the air. So, even as "El Niño" wreaks havoc on the Amazon, it can provide a slight reprieve for local residents in such states as Louisiana.
But not so fast: What happens when El Niño goes away? During an off-season, the globe sees the rise of "La Niña", wherein warm ocean waters migrate back to the far western Pacific and we get abnormally cool sea-surface temperatures. While some might welcome La Niña since the phenomenon moderates the impact of greenhouse gas-driven warming, there are downsides. Specifically, La Niña spells danger for the Gulf since the cycle spurs hurricanes in the area. That is because in La Niña, unlike El Niño, wind shear is reduced over the Atlantic. And, when less wind shear is present, hurricanes can climb and strengthen. Gulf residents are afraid of precisely that, and already the U.S. government's Climate Prediction Center is declaring that La Niña conditions are likely to prevail in July and August.
Though La Niña's arrival is certainly ominous, Louisiana natives might take some comfort in the notion that once the cycle is complete the Gulf might get some peace as we go back to El Niño. But now, even El Niño has been thrown off kilter and the El Niño-La Niña cycle has been changing. New studies suggest that El Niño is gradually being replaced by something called "El Niño Modoki", which in Japanese means "similar but different." Perhaps researchers claiming that El Niño had become more frequent and more intense were simply on to a new meteorological form.
Unlike the traditional El Niño, which forms in the eastern Pacific, El Niño Modoki forms thousands of miles west near the International Date Line in the central Pacific. Modoki is poised to become a powerhouse and could strike five times more often than the normal El Niño by the end of the century. To make matters worse, Modoki could have an impact on Gulf hurricanes. That is because Modoki's westward Pacific shift may shift Atlantic hurricanes westward. One other unwelcome development is that hurricanes could become more frequent and strike land more often along the Gulf coast.
Why is El Niño changing to El Niño Modoki? It's anyone's guess, though one possible explanation is that Modoki simply forms part of El Niño's natural oscillation. Another more troubling possibility is that Modoki is El Niño's response to a warming atmosphere. Already there are hints that Pacific trade winds have become weaker over time, and this in turn may result in warming taking place further to the west. At this point, we need more data to be determine what, exactly, is happening in the Pacific.
In any case, with climate warming and El Niño changing the future is likely to be stormy for the Gulf. Over the past twenty years, Modoki events have increased from approximately one out of every five to half of all El Niño events. While most everyone is paying attention to oil spills in the Gulf, it may be that we are missing the eight hundred pound gorilla in the closet. The petroleum industry certainly gives rise to pollution, but it is the warming effect of our fossil fuel economy which is causing greater impacts through climatic disturbance. In a ricochet-type effect, that same climate disturbance could now hamper environmental efforts to clean up the BP spill in the Gulf of Mexico.
Nikolas Kozloff is the author of No Rain in the Amazon: How South America's Climate Change Affects the Entire Planet (Palgrave-Macmillan)
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