Friday, May 21, 2010

Oil spills are not the calamity doom-mongers say they are

Yes, oil spills are terrible. But the truth is they're not the calamity doom-mongers say they are

A few names stand out as symbols of Man’s profligacy and carelessness in the environmental hall of infamy.

These must include Torrey Canyon, Amoco Cadiz and Exxon Valdez — huge oil spills that led not to massive loss of human life, but, we are told, to ecological destruction on a scale never before seen. To this list we must now add ‘Deepwater Horizon’, the huge BP drilling platform in the Gulf of Mexico which exploded on April 20.

Since then, around 10-12 million litres of crude oil have been gushing every day from the broken wellhead, a mile down on the seafloor.

Despairing environmentalists, together with politicians and scientists, say that this has led to the greatest ecological disaster in U.S. history with thousands of tonnes of oil set to ruin the pristine shores of the Gulf, kill millions of seabirds, fish and marine mammals, and decimate the lucrative fishing industries of America’s swampy underbelly.

Already, green campaigners have pointed to the spill as yet another sign that modern Man’s dependency on oil amounts to a Faustian pact with an evil subterranean devil; not only does oil wreck our climate when it is burned, releasing warming carbon dioxide into the atmosphere, its very substance amounts to a prehistoric poison unleashed by our demonic technologies.

But the truth is that when it comes to oil spills — and other environmental disasters — history tells us something very puzzling and counter-intuitive.
Despite the appalling pictures beamed onto our screens — the oil-covered seabirds, the grim tides of dead fish, the blackened beaches and disgusting oozing mess at the water’s edge — Nature has seen that, usually within a year or two or even less, places affected by oil spills have returned more or less to normal, the disaster forgotten.

Indeed, many experts now believe that if left to run their natural course, it is likely that the effects of even the worst disasters are nullified.

How can this be? Are oil spills really less bad than we have been led to believe?
Certainly, our attempts to deal with them can often cause far more havoc and destruction than the spills themselves.

In March 1967, the oil tanker Torrey Canyon ran aground off the Scilly Isles en route from the Gulf to Milford Haven.

As the ship foundered and started to break up with its 120,000 tonnes of crude leaking into the Atlantic, the world faced its first major oil-spill disaster. A huge slick was heading for the holiday beaches of Cornwall.

First, the RAF bombed the stricken tanker, in an effort to burn off the oil. Most of the bombs missed and the effect was to accelerate the rate at which oil leaked into the sea.

Next, 10,000 tonnes of industrial-strength detergents were sprayed on the oil by teams on 42 ships in an effort to disperse it all. These chemicals had little effect on the slick, but they poisoned millions of marine organisms and probably caused far more damage to the ecosystem than the oil itself.

At one point, huge drums of detergent were simply poured onto the beaches around Land’s End in the hope that, should the oil wash ashore, this would keep the sands clean. At Sennen Cove, huge quantities of solvent were ploughed into the sand — meaning that the oil was held in situ for months.

There is no doubt that the oil from the Torrey Canyon was toxic and killed a lot of animals, as well as being unsightly. But experts are now convinced that the best solution, short of pumping the oil off the tanker before it could escape or otherwise trying to contain it, would have simply been to do nothing.

According to Dr Simon Boxall, an oceanographer and oil-spill expert at Southampton University: ‘Crude oil is a natural product (being rotting vegetation — albeit modified by age and pressure) and in the environment breaks down naturally through bacterial decay.’

In fact, thousands of tonnes of crude oil, far more than is spilled as a result of man-made disasters, seeps from the seabed naturally every year. The main difference with a ship or oil well disaster is its suddenness and localised nature.
Of course, there is nothing good about an oil spill. If one happens near land, then not only are marine ecosystems threatened but also the fragile coastal ecologies upon which thousands may depend for their livelihood.

The most obvious short-term threat is to tourism; no one wants to lie on a beach sticky with a layer of tar and swim in a sea shining with the telltale rainbow iridescence of floating oil.

Oil spills can kill marine organisms in their millions, and can have a devastating effect on fragile ecosystems such as coral reefs and mangrove swamps. Modern dispersant chemicals are far gentler and more effective than those used in the Torrey Canyon disaster.

But the good news is that these disasters ARE short-term. The environment will recover. And the speed with which it does so depends on the grade of the oil, how much was spilt, the sea temperature, the amount of sunlight, tidal mixing and wave conditions.

What is astonishing is that in most cases, complete recovery takes less than two years.

For example, in December 1999, the MV Erika sank in the Bay of Biscay, and within days a huge oil slick washed up on the beaches of southern Brittany.
News reports showed heartrending pictures of stricken seals as thousands of volunteers battled to clear up the mess.

But despite predictions that the Brittany coast would be ruined for years, the fact was that by the following summer most of the oil had been effectively dispersed and there was certainly no sign of any oil on the beaches when I had a family holiday there less than two years later.

Even more strikingly, when the Braer ran aground off Shetland in 1993, there were widespread predictions of an environmental catastrophe. Some reports suggested that seabird populations could be decimated for 70 years.
In fact, gale-force winds combined with the fact the spill consisted of a very light crude so that, apart from a few hundred affected birds (and some badly-oiled sheep), the environmental effects were so minor that, in the words of marine Biologist Prof Chris Frid of Liverpool University, ‘they were hard to measure’.
Crude oil is a mix of natural hydrocarbons, from light spirits to thick tars. The light oil tends to evaporate quickly and the thicker stuff can be ‘digested’ by marine microbes quite efficiently.

In open oceans, even a large spill will disperse in a few weeks. Closer to shore, there is plenty we can do but we should not overreact.

Oiled seabirds are heartwrenching (and make great TV) but in reality their numbers tend not to be great — birds simply tend to fly away from polluted sea.
Of course, our society depends on oil; until an alternative can be found, it would be foolish to pretend otherwise and in this sense we are all to blame for the Louisiana spill.

Understandably, people living on the Gulf Coast are fearful (and, it must be said, keen to obtain any compensation that may be on offer).
But the fact is these accidents will happen. And the lessons from Nature is that whatever happens from now on, in a couple of years’ time, the silver sands of Florida’s Gulf Coast will be as pristine as they were before the spill.

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