Eating Down the Food Chain

Europe once teemed with large mammals, including species of elephant, lion, tiger, bear, moose and bison.

America was also home to a number of huge and unusual animals: mammoths, dire wolves, lions, giant sloths and others.

The same goes for Australia, where giant kangaroos, huge wombats and marsupial 'lions' once roamed.

What do these extinctions have in common? They all occurred around when humans arrived. The idea that humans caused them is hotly debated, because they also sometimes coincided with climactic and vegetation changes. However, I believe the fact that these extinctions occurred on several different continents about when humans arrived points to an anthropogenic explanation.

A recent archaeological study from the island of Tasmania off the coast of Australia supports the idea that humans were behind the Australian extinctions. Many large animals went extinct around the time when humans arrived in Australia, but that time also coincided with a change in climate. What the new study shows is that the same large animals survived for another 5,000 years in Tasmania... until humans arrived there from the mainland. Then they promptly went extinct. That time period didn't correspond to a major climate change, so it's hard to explain it away.

It's a harsh reality that our big brains and remarkable adaptability give us the power to be exceptionally destructive to the environment. We're good at finding the most productive niches available, and exploiting them until they implode. Jared Diamond wrote an excellent book on the subject called Collapse, which details how nearly every major civilization collapse throughout history was caused at least in part by environmental damage. It's been a hallmark of human history since the beginning.

I don't think it will take much to convince you that the trend has accelerated in modern times. Ocean life, our major source of nutrient-rich wild food, has already been severely depleted. The current extinction rate is estimated to be over 1,000 times the baseline, pre-modern level, and rising.

Humans have always been top-level predators. We kill and eat nutrient-dense prey that is often much larger than we are. But today, the extinction of such walking meat lockers has caused us to eat down the food chain. We're turning to jellyfish and sea cucumbers and... gasp... lobsters!

While it's true that we've probably always eaten things like shellfish and insects, I find it disturbing that we've depleted the oceans to the point where we can no longer sustainably eat formerly abundant carnivorous fish like tuna. We need to make a concerted effort to preserve these species because extinction is permanent.

I don't want to live in a future where the only thing on the menu is bacteria patties, the other other other other white meat.

Improving Fuel Economy

OK, you know driving isn't good for the environment, but you're going to do it anyway. Here's how to substantially increase your fuel economy without buying a new car:

1- Drive deliberately; accelerate gradually. A car uses a lot of fuel when it's accelerating rapidly.

2- Drive 55 mph on the highway. This makes a huge difference. It maximizes fuel efficiency by reducing wind resistance, which exponentially increases with speed. This reduces gas consumption by more than 20% relative to a speed of 75 mph. 60 mph is almost as good, if 55 is to slow.

3- Draft a truck. Large trucks with flat, square backs leave a massive low-pressure zone behind them, which you can exploit to save gas. At 20 feet behind a standard 18-wheeler, you will use about 27% less fuel. If that's too close, you still save 20% at 50 feet, and 11% at 100 feet. Be careful because trucks have a blind spot behind them, and some truckers do not appreciate drafting.

4- Keep your car well-maintained. Clogged filters, faulty oxygen sensors and flat tires all hurt fuel efficiency.

5- Lose the cargo. The more weight you have in your car, the more fuel is required to get it up a hill or accelerate it.

6- Turn off accessories. AC is the biggest power drain, but the fan used to circulate air also draws power.

Two Tons of Steel

While I was waiting for the bus one morning, I decided I'd count cars to see how many were single-occupancy vs. two or more. I came up with a ratio of roughly 20 single-occupancy vehicles for every multiple-occupancy vehicle. The multiple-occupancy vehicles were most often work trucks, containing plumbers or construction workers going to a job.

People have to get to work. Maybe they don't have public transit where they are, or maybe they just don't feel like sitting next to smelly commuters, but for whatever reason, here in the U.S. they drive their cars.

The average American weighs about 180 lbs. Due to our love affair with SUVs, the average American car weighs over 2 tons and climbing. That means every time a person drives a single-occupancy vehicle to work, they aren't just expending the energy it takes to move 180 lbs 15 miles. They're also lugging around a hulking two-ton chunk of steel and plastic. The passenger of the average single-occupancy vehicle is only about 1/24 (4%) of the mass that's being moved to and from work. That's ridiculous!

Of course, we make up for the big weight of our cars with big engines so they can go vroom. That adds up to a lot of gasoline burned, for no clear benefit. In other words, most of us could easily be driving vehicles that perform the exact same function but burn 1/3 the gasoline. I'm not talking about space-age technology here; these vehicles are already on the market.

Why do we commute so inefficiently when better options surround us? I think there are several reasons. First of all, gasoline is dirt cheap. We have no incentive to be efficient beyond our own consciences. Even with the recent price jumps, gasoline doesn't cost much more than it ever has, if you adjust for inflation. In Europe, where high taxes mean gasoline can cost four times as much as in the US, vehicles are lighter and more efficient.

Secondly, we've always been a very car-centric society. Cars appeal to our desire for independence, power and control. A large, powerful car is a status symbol in the US. We've inherited these attitudes from previous generations and we're just beginning to question them. Are there healthier and less wasteful ways of getting to work?

There are, and many of them are very simple. The first and simplest is a carpool. If we put two average Americans in our two-ton car, all of a sudden the people are 1/12 the weight of the vehicle. With four people, the number jumps to 1/6. We've just made our vehicle almost four times as fuel efficient, per passenger! 1,000 lbs per person is still a lot of weight to be lugging around though, so let's look at some other options.

If you are on the market for a new car, fuel-efficient models abound. The new hybrid cars by Toyota and Honda are twice as efficient as their non-hybrid brethren, and not much more expensive. Some people truly need SUVs for their business, but I have good news for them too: there are now hybrid SUVs as well. That's right ladies and gentlemen, they're the most efficient gas guzzlers on the market.

Public transportation is another great option where it's available. Buses are big and heavy but they can accommodate many people.

Now let's get into the really efficient vehicles. Motorcycles and scooters weigh from 250-500 pounds, meaning that a passenger would be from 1/2 to 1/4 the total weight of the vehicle. Now we're beginning to make some sense. Certain scooters can go over 100 miles per gallon of gasoline.

An even better option is to use vehicles that don't burn gasoline at all. A bicycle weighs about 20-30 pounds, making the passenger about 9/10 of the total vehicle weight. That weight ratio might change as the average American loses some weight however. Even if you factor in the extra food you eat when you cycle regularly, it's still terribly efficient. Best of all, bikes allow us to get exercise and feel the sun for a while.

The title for the most fuel-efficient and low-tech vehicle around goes to feet. When using a pair of these, the passenger is 100% of the weight of the vehicle. You can walk until you wear them out and you still won't have burned a single molecule of gasoline. Now that's efficient.

Thanks to lairdscott for the CC photo.