More reasons for reduced guilt while flying

I feel less guilty flying on vacation now that I’ve compared flying with driving by car. Both contribute to global warming about the same.

image: alternet

Comparisons between the two are tricky because there are many factors like the efficiency of the car and how many are traveling. And the distance the plane flies: more fuel is used on takeoff so longer flights are more efficient. The University of Oslo has weighed these factors and concludes: “With only one passenger in the car, corresponding to 20-25% occupancy, the climate impact is at the level of an average air trip (Yale Climate Connections).”

My burden of guilt might be reduced even further. Canadian airlines are looking at using renewable energy rather than fossil fuels. (Globe and Mail, July 25, 2107)”.

Air Canada has flown eight times on biofuels, most recently from Edmonton to San Francisco on May 2, 2018. The flight reduced carbon emissions by over ten tonnes, a 20% reduction in net carbon emissions. This is equivalent to taking 26 cars off the road for a month according to Air Canada. They are careful to say that the growth of biofuels can’t come at the expense of food crops. That should be easy because some land that is unsuitable for food may be fine for biofuels.

Even more arable land will come available because of global warming caused by people (gulp) going on vacation and spewing CO2 into the atmosphere.

Air Canada has also improved fuel efficiency by 43 per cent since 1990 and they hope to be carbon-neutral by 2020. “These efforts and other green initiatives to increase efficiency and reduce waste were recognized by Air Transport World which earlier this year named Air Canada the Eco-Airline of the Year for 2018,” they say.

Planes are becoming more efficient. That, combined with cleaner burning biofuels can reduce air pollution. According to NASA, a mixture of 50% aviation biofuel can cut air pollution caused up to 70%.

If I flew on a plane that used solar, electric or hydrogen fuels, that would be even better. But for now those sources don’t have the power necessary to launch commercial airplanes.

I could also buy carbon offsets to pay for my sins of emissions. WestJet has teamed up with Carbon Zero. Their calculator shows that my return trip to Puerto Vallarta, Mexico, generates 0.65 Tonnes of CO2. For an additional $14.69 I can contribute to an equal reduction of greenhouse gases. They offer two projects. One is diversion of organic waste from a Toronto landfill which prevents methane from escaping into the atmosphere. That’s good: methane is an even worse greenhouse gas than CO2.

However, while I may feel a little better, carbon offsets are a drop in the bucket. Offsets nowhere match the amount of carbon going into the atmosphere.

In addition, carbon offsets only appeal to people who worry about such things. For those who don’t think that humans contribute to global warming, offsets may look like a scam.

No guilt would better than reduced guilt but I can console myself, somewhat, by comparing myself with those who don’t give it a fleeting second thought.

Advertisements

Lies, damn lies, and category 1 carcinogens

The World Health Organization recently placed processed meat in category 1 of carcinogens, along with radioactive elements and asbestos. That’s the list of agents “carcinogenic to humans.” They also placed red meat in 2A which includes Glyphosate (Roundup) and lead compounds which are merely “probably carcinogenic to humans.”

bacon

Is eating bacon more likely to cause cancer than exposure to an herbicide? No. Agents aren’t listed according to risk. The criterion used is: do they or do they not cause cancer. The categories are grouped by experts according to certainty from the most evident all the way down to category 4, “Probably not carcinogenic to humans” of which there is one item, Caprolactam (used to make nylon).

Risk is determined by how much you are exposed to the carcinogen. André Picard, public health reporter for the Globe and Mail explains:

“The expert group does hazard identification, not risk assessment. Practically, that means they determine, yes or no, whether something may cause cancer, but not how potent it is at a causing cancer,” and adds, “It’s important to remember, however, that not every exposure to a potential carcinogen will cause cancer: Frequency, intensity and potency matter.”

All agents in a category don’t carry the same risk. If they did, people would be dropping like flies from eating meat. Compared to other items, they are not.

Eating processed meat and smoking tobacco, both in category 1, don’t have the same mortality rate. Processed meats result in 34,000 deaths worldwide annually whereas smoking causes about one million cancer deaths. Also in category 1, asbestos kills more than 100,000 and alcohol causes 600,000 cancer deaths a year.

Also misleading is the way percentages are used to translate statistics. For example, two slices of bacon are reported to increase your risk of colorectal cancer by 18 per cent. Eating a 4 ounce steak will result in a similar increase. But when risks of colorectal cancer are low to begin with, a small percentage increase of a small risk is still a small risk. The actual numbers expose this fallacy, explains Pickard:

“Based on these estimates, about 66 in every 1,000 people who eat a lot of red meat or processed meat will develop colorectal cancer in their lifetime; by comparison, 56 of every 1,000 who eat very little meat, processed or otherwise, will develop colorectal cancer.”

In other words, the increased risk is 10 out of 1,000. If you are one of those 10 persons who acquire cancer from eating meat, it’s tragic but as a risk assessment it’s not that bad.

Risk assessment is complicated by the toxicity of the agent, the amount of the agent you are exposed to, the length of time exposed to it, the way you are exposed (inhaled, ingested, topically applied), and your genetics.

The categories are useful in determining what to avoid, if possible. But some things are almost unavoidable. Like living: walking in the sun (ultraviolet rays), working (painter, hairdressers and shift-workers), eating (barbequing at high temperatures), camping (wood smoke), and travelling (cosmic rays from flying in a plane, breathing vehicle exhaust).

Unavoidable, like being alive: the naturally produced hormone estrogen has been linked with cancer, especially when combined with the artificial hormone progestin.