100 tons CO2e a carbon-conscious child
373 tons CO2e average in U.K.
688 tons CO2e average in North America
2,000+ tons CO2e high-impact offspring
> So if you have two typical children, that’s 746 tons over their lifetimes.
Unless you will ever contemplate lighting a forest fire (see A forest fire), the decision to reproduce is probably the biggest carbon choice you will ever make. The more of us there are, the greater the pressure on the world’s resources.
I’m not saying you shouldn’t have children. If you are someone who believes that God has told you to go and have ten of them, I am not even saying that you are wrong about that. All I’m saying is that according to my sums one of the consequences will be a few thousand tons of carbon emissions.
The average U.S. and U.K. lifetime footprints are based on your child living to the U.K. life expectancy of 79 years. I have assumed that during that time he or she will lead a nationally typical lifestyle in carbon terms and make average demands on public services. I have also assumed that throughout his or her life the average carbon footprint of a person living in the U.K. will decrease by 3.9 percent each year. This is the same annual reduction that is required if the U.K. is to meet its target of cutting emissions by 80 percent by 2050 (at which point your child will be roughly halfway through his or her life).1
At the high end of the scale are children who, even after you have done your best to encourage sustainability values, then go on to lead high-carbon lives. At the low end of my scale are children who grow up with carbon priorities embedded in their lifestyle and are serious about reducing emissions where they can.
All my scenarios assume that the child is living in the developed world (the numbers would be much lower in developing countries). For simplicity’s sake I have not taken into account the footprint of your child’s own offspring.
Deciding whether or not to have children is one thing, but the Optimum Population Trust2 estimates that 40 percent of all pregnancies worldwide are unintended and that offering family planning in developing countries saves carbon at a rate of $6 per ton.
400 tons CO2e per year
> That’s the same as 40 people living the 10-ton lifestyle or just over the expected lifetime footprint of a child born in the U.K. today.
The figures here are for a community swimming pool with a spa, costing $37 million3 to build They are based on a real study carried out for a pool in a small town in Scotland. The study concluded that the pool in question caused a massive 17 kg (38 lbs.) CO2e per visitor, around 30 percent of which could be prevented just through simple improvements in efficiency.
As Figure 10.1 shows, most of the pool’s gas was consumed in the process of heating the water. Electricity was used mainly for pumps, air extraction, and lighting. Most visitors traveled a fair distance by car to get there, and that accounted for 20 percent of the footprint. Note that the water itself was barely significant.
FIGURE 10.1: The footprint of a swimming pool in a small Scottish town.
Overall, do the high figures here mean we should all stop swimming? There are at least a couple of things to bear in mind before making that leap: the huge social benefits of swimming pools and the fact that an efficient and busy pool in a bigger town could perhaps cut the footprint per swim to one-quarter of the numbers here. Unless you actually believe your local pool should close (in which case there is an argument for avoiding going there), remember that when you swim in it, you hardly alter its footprint at all: you just put it to better use. Nonetheless, swimming remains a surprisingly high-carbon way to take exercise.
A hectare (2.5 acres) of deforestation
500 tons CO2e
> That’s equivalent to an average car driving 700,000 miles—28 times around the world.
A hectare is 100 m x 100 m (330 ft. x 330 ft.), so there are 100 of them in a square kilometer and about 260 of them in a square mile. Globally we are cutting down or burning about 32 million acres of rainforest per year. That’s about half the land area of the U.K. The result is about 9 billion tons CO2e or 17 percent of all man-made emissions.4
| Country | Total forest area | |||
| 1 | Russian Federation | 3,122,755 sq. mi. | ||
| 2 | Brazil | 1,844,402 sq. mi. | ||
| 3 | Canada | 1,197,434 sq. mi. | ||
| 4 | United States of America | 1,170,223 sq. mi. | ||
| 5 | China | 761,740 sq. mi. | ||
| 6 | Australia | 631,964 sq. mi. | ||
| 7 | Democratic Republic of the Congo | 515,871 sq. mi. | ||
| 8 | Indonesia | 341,681 sq. mi. | ||
| 9 | Peru | 265,414 sq. mi. | ||
| 10 | India | 261,395 sq. mi. | ||
TABLE 10.1: Top ten countries by total forest area.
Most of this total (about 22 million acres or 6 billion tons) involves clearing forest to make way for livestock and other agriculture. One estimate is that 20 to 25 percent of rainforest loss is due to cattle grazing, 35 to 45 percent to small holdings, 15 to 20 percent to intensive agriculture, 10 to 15 percent to logging, and perhaps 5 percent to other causes such as urbanization, mining, roads, and other infrastructure.5
Anything that increases the land we need for agriculture drives deforestation. Included in this list are high-meat diets, cut flowers, and biofuel crops. In Brazil, where deforestation accounts for 70 percent of emissions, rates had been falling since 2004 until a spike in beef and soy prices brought on a further increase.
Halting deforestation is potentially one of the easiest climate change wins, if only we can find the mechanism. Brazil has pledged to cut its levels by 80 percent over the next decade. That is a big win. The Amazon Fund6 pays farmers to hang on to their trees. It works out at just $4.5 per ton of carbon saved.7 What a bargain! It is also fantastic for biodiversity. The Norwegian government has pledged $1 billion to support this. Why don’t other governments get into this kind of thing?
The Boreal forest accounts for around a third of the world’s forests, with the Canadian part alone storing an estimated 186 billion tons CO2e; that’s nearly four years’ worth of humankind’s greenhouse gas footprint. The Boreal’s role in our climate is so significant that when it is summer in the Northern Hemisphere and the trees are growing at their fastest, global CO2 concentrations actually come down slightly.
According to the Food and Agriculture Organization of the United Nations, Canada and the U.S. rank third and fourth in terms of total area covered.8
At least 4,600 tons CO2e
> That’s the same as two bananas for everyone in Canada or half a sheet of recycled toilet paper for everyone in the whole world.
A NASA space shuttle used to burn through 106 tons of hydrogen in its external tank (the big one that would fall off after a couple of minutes and disintegrate before hitting the ground) and 527 tons of extra high-energy solid fuel in each of the two booster rockets.9
My carbon estimate is conservative for a variety of reasons. I have made the assumption that the process of creating the hydrogen and solid fuel using energy from fossil fuels has been 80 percent efficient. In other words I’ve assumed that four-fifths of the energy in the fossil fuel is transferred into the shuttle fuel. That is about as efficient as hydrogen generation ever gets, and frankly I would be surprised if energy efficiency was NASA’s number one priority. I would be even more surprised if the manufacturing of the solid fuel was that efficient.
Much more significantly, it might have been reasonable to add on a large chunk of footprint of NASA itself. Richard Feynman, the Nobel Prize–winning physicist who helped to investigate the Challenger disaster, describes the shuttle project as NASA’s somewhat unjustifiable raison d’être after the lunar landings.10
My third major omission is that I haven’t included any kind of weighting factor to take account of the high altitude at which the emissions are released. When it is actually in the air, the shuttle burns a different type of fuel from a normal plane, and it releases different gases. It won’t be the same story as for normal aircraft, since the gases and altitudes are both different. Somewhere along the line the water from burning hydrogen probably causes some contrails, but that’s about all I can say. I would love to hear from anyone who knows more about this.
Finally, I haven’t bothered to factor in the embodied energy of the shuttle itself. Since each shuttle (apart from Challenger, which crashed after ten trips) was reused around thirty times, I think the emissions of manufacture would turn out to be very small compared with the fuel burn.
Space tourism is not a low-carbon option.
72,000 tons CO2e per year
> So that’s about 5.5 tons for each staff member and student.
The figures here are based on a study for Lancaster University. It included just about everything you can think of: gas, electricity, commuting, business travel, and everything the university buys, right down to the paper clips. It even included intangibles such as software and banking services. It didn’t include everyday food because the university only caters for special events.
As Figure 10.2 shows, gas and electricity between them accounted for 45 percent of the total. Staff air travel came in at 10 percent, and staff and student car travel came in at about 7 percent each. Everything else that the university buys made up the remaining quarter of the footprint: IT equipment (5 percent), building maintenance (5 percent), paper based stuff (1 percent), and so on.
FIGURE 10.2: The carbon footprint of Lancaster University.
IT in total accounted for about 12 percent, with nearly half of that being due to the electricity consumed by computers themselves and a sixth to the power consumed by servers and other computing infrastructure, including the air conditioning to cool it all down. The remaining third was due to the embodied emissions in the equipment itself, with a little bit for services such as Internet access and software.
I’d love to be able to write about how Lancaster compares with other universities, but it wouldn’t be meaningful, because no two are in the same situation. Lancaster is a fairly small campus university on a hill in the north of the U.K. with lots of buildings from the sixties and a few new ones. Oxford is farther south but can be bitterly cold in winter. It isn’t on a hill but has to make the best of a load of ancient listed buildings. How could the two be compared? Also, I don’t know of another university that has had quite such a comprehensive study carried out. They usually only look at electricity, gas, and travel. Lancaster has about one-third of the enrollment of McGill University in Montreal, and roughly a fifth of the enrollment of the University of Florida.
Lancaster University’s footprint per head is about a third of the annual footprint of a typical British person. But don’t forget that everyone at the university has plenty more in their footprint than the stuff covered by the university. The sums here don’t take account of students and staff traveling to and from home, for example.11
How to reduce it? I won’t go into too much detail here, except to say that at the time of writing, great ideas are coming from all kinds of places. Some are very technical (IT wizardry), some are mind-blowingly simple (change the light bulbs) and some are quirky ideas that bright people have dreamed up out of the blue in odd moments (like bits of hose pipe attached to air conditioning units to improve their efficiency). The biggest challenge is not having the ideas but putting them into action.
Educational establishments account for nearly 2 percent of the U.K.’s total footprint.