Perspective — Food for Thought

Perspective is an editorial column I write regularly for FiNS Magazine. This installment is entitled "Food for Thought":

Slipping under the waves often entails first taking to the skies. In fact, long-distance air travel is an integral part of our ongoing quest to find the newest and best dive sites.

Other than the hassle of finding decent fares, dealing with restrictive baggage allowances, suffering through terrible in-flight meals, persevering through interrogations by surly customs officials and putting up with similar annoyances, most divers rarely give air transport a second thought. It’s a necessary evil, so to speak.

New information, however, suggests that we may have to think again. Recent studies indicate that air travel is a significant contributor to the potential problem of global warming. Most sources seem to concur that while the aviation sector contributes a relatively small percentage of global greenhouse gases, the net effect of aircraft emissions on global warming is disproportionately high.

The issue first came to light with the 1999 United Nations Intergovernmental Panel on Climate Change (IPCC) report, which ranked transportation as the second largest contributor of global greenhouse-gas emissions, behind power generation (responsible for 27% and 34% of all emissions, respectively).

Within the transport sector, the airline industry accounts for 3% of global emissions, according to the report. This isn’t a large number, so what’s the big deal?

First, CO2 emissions from commercial aircraft are at high altitude, which causes more damage than ground-based emissions. Second, nitrogen oxides from jet engines lead to ozone creation, which is another greenhouse gas. Also, contrails (those streaks of cloud you see behind jet planes) stimulate cirrus cloud formation, which some scientists believe exacerbate global warming.

Bottom line — these factors and more multiply the global warming effect of air transport beyond the 3% IPCC estimate by a factor of between two and four times. On top of that, air transport is believed to be the most rapidly growing contributor of greenhouse-gas emissions.

So what does this mean for travelling divers?

Take this example into consideration — A jumbo jet flying one-way from London to Sydney has a global-warming impact roughly equivalent to 400 small cars each going 16,000 kilometres. So, if you were a passenger on that plane, you would have been responsible for producing greenhouse gases equivalent to emissions from an entire year or more of driving. And that’s for a one-way ticket only!

You can reduce your energy consumption at home, throw your car away, bicycle to work, and buy only local goods to reduce your share of greenhouse-gas emissions, but take just one long-haul trip, and you will have totally negated all of that and more.

With global air traffic growing at an estimated 5-10% each year, it also means that projected growth in air travel may offset most, if not all, carbon reductions under the Kyoto Protocol. Clearly, we’re not going to do away with air travel, and most divers are not going to forsake dive trips to pristine far-flung destinations because of this.

Divers, however, tend to be an environmentally-minded lot, and I often hear criticism among divers of politicians, bureaucrats, companies, etc. for not doing enough to protect the environment.

So here’s some food for thought — If the scientists are correct, then every time you fly to dive, you join the ranks of the planet’s worst greenhouse-gas offenders, and you help to hasten the demise of the pristine environment you’re travelling to enjoy. Heavy, huh?