Michael McCarthy: The oil disaster teaches that technology is not infallible

The environment

Was it the world's worst pollution disaster? You can make a pretty good case that it was. Now BP's Deepwater Horizon oil spill appears to have been finally shut down after 87 days of pouring Louisiana crude into the waters of the Gulf of Mexico in an unremitting torrent.

It will certainly be up there forever in the pages of environmental infamy alongside the Chernobyl nuclear accident of 1986 in the Ukraine, and the Bhopal mass gassing of 1984 in India. And in terms simply of pollution emitted, it now appears to be nudging the top of the oil-spill list, possibly exceeded only by the giant spill in the final days of the 1991 Iraq war, when retreating Iraqi forces opened the valves of the Sea Island oil terminal in Kuwait.

That released between two and six million barrels of oil, whereas Deepwater Horizon, depending on the estimate, has released more than 2.2 million barrels, and possibly as much as 5.3 million. The Gulf leak exceeds the worst offshore spill to date, the blowout of the Ixtoc 1 well off the Mexican coast in 1979-80, when about 3.5 million barrels were released.

The impact of Deepwater Horizon's pollution is threefold: environmental, socio-economic and psychological.

Environmentally, the fears are enormous, but the effects are hard to judge accurately. The ruptured well began gushing on 20 April, which was in the early stages of the breeding season for Gulf wildlife, and there was instant concern for a range of creatures, ranging from bluefin tuna and green turtles to the brown pelican, the state bird of Louisiana.

Three months on, the effects are less than first feared, especially on oiled seabirds. As of Wednesday, the total of oiled birds picked up over the three months, alive and dead, was 1,997. About 400 were brown pelicans, about 200 were laughing gulls, and the rest comprised a range of species.

While no one would minimise the harm of this – and having seen oiled brown pelicans at first hand in Louisiana in early June, I can testify to the depths of their misery – it is a much lighter toll than the thousands and thousands of oiled birds conservationists were anticipating. "It's tiny compared to what we thought it would be," Greg Butcher, conservation director of the National Audubon Society, America's equivalent of the RSPB, said yesterday.

Dr Butcher highlights several reasons for the comparatively low number of affected birds: much of the slick is still offshore, many more oiled birds may have died out at sea and not been collected, and rescuers are reluctant to chase oiled birds into breeding colonies.

But it may also be the case that the gigantic, BP-funded clean-up operation has protected them and much of the Gulf coast. The scale of this is quite staggering and appears to exceed any previous environmental-control venture: nearly 7,000 ships and boats and 119 aircraft are involved, almost 2,000 miles of protective booms have been deployed and there are 44,000 personnel on active duty.

So far, this has cost BP $3.5bn (£2.9bn), and when you start looking at the numbers you begin to get an idea of the impact of Deepwater Horizon on the economic life of the communities along the Gulf coast. This has been immense, as the shrimp-fishing, oyster-fishing and tourist charter-boat fishing industries, which along with oil are the mainstays of the Gulf economy, have been completely shut down. BP has been paying boat skippers $5,000 a month in lost earnings, and it has already issued 16,200 cheques for $5,000 dollars or more, and more than 64,000 cheques in all, for a compensation total so far of $201m. That's just in three months – and remember, this is only what BP has paid before any legal actions are launched, when the damages which litigants will seek to recover will dwarf these sums.

So if we look at the Gulf spill in socio-economic rather than purely environmental terms, the case for it being the worst pollution disaster ever is clearer; but it is perhaps clearest of all if we look at its psychological effect.

Deepwater Horizon has changed the way we regard the oil industry. What set this disaster apart is that the spill was continuous – that for so long it just could not be stopped. In this it was very different from Chernobyl, an explosion lasting a fraction of a second, or Bhopal, a gassing which took several hours.

But Deepwater Horizon gushed on and on, with the oil industry experts seemingly powerless to stop it; and it was this above all which troubled the citizens of the Gulf coast. Deepwater Horizon shows us what can happen when we get too clever and think that sinking oil wells 5,000ft under the surface of the sea is a piece of cake; it has shown us unforgettably that our shiny, state-of-the-art technology is not infallible, and reminded us forcefully that human wisdom has its limits.