Ecological footprint and carbon footprint

Where did your skateboard come from? A skate shop is the obvious answer, and maybe a factory before that. But your board is also a maple forest, a bauxite mine and an oil well. The deck was a tree, the aluminium trucks were dug out of the ground, and the polyurethane wheels began as crude oil. You have never been to any of those places, but your board left a mark on all three. Forest, mine and oil well each paid a price for that one board.

A product's ecological footprint is the damage it does to the natural world, meaning the land, water, air and wildlife, from getting its raw materials to its final disposal. An ecological point is about the natural world. A social point is about people instead: their pay, their jobs, their safety. Here are two points about a cotton T-shirt. In one, the cotton farms drain a nearby river. In the other, the cotton pickers are paid too little. Which of the two is an ecological point, and why? The drained river. It is damage to the natural world. Low pay is a real problem, but it is about people, so it belongs to a social question. One examiner's report says this: Some students discussed fair trade and employment issues which are not ecological issues required by the question and hence incorrect. The fix is to keep every point on the natural world: land, water, air and wildlife. Fair trade and wages belong to a different question.

Raw materials reach a product in four ways: deforestation, mining, drilling and farming. Each one leaves its own mark. Deforestation is cutting down forests faster than they regrow, for timber and paper, or to clear land for farms and mines. Habitats are lost, and fewer trees are left to absorb carbon dioxide. Mining digs out ores: bauxite for aluminium, iron ore for steel, copper for wiring. Land is stripped, waste rock is piled up, and nearby water can be polluted. Drilling pumps up crude oil and gas, the start of almost every polymer. It uses energy, risks spills on land and at sea, and uses up a finite resource. Farming grows cotton for fabric, and grazing land feeds the sheep and cattle behind wool and leather. Cotton needs huge amounts of water and usually pesticides, and land is cleared to grow it. Here is a bigger one, on a school backpack, and it finishes with a judgement about which part matters most. Canvas body, nylon straps, aluminium buckle, card tag: each part's route and harm? The canvas is farming: cotton needs lots of water and pesticides, which can drain rivers and poison wildlife. The nylon straps are drilling: nylon is made from crude oil, a finite resource, and drilling risks spills. The buckle is mining: bauxite comes from open-cast mines that strip land and destroy habitats, and turning it into aluminium takes a lot of electricity. The tag is deforestation, unless its card is recycled or from managed forests. The canvas is most of the bag, so farming is probably its biggest issue, though the buckle carries a high energy cost for its size. The designer does most good with lower-impact cotton and recycled aluminium, then card from managed forests. One examiner's report records this: Many candidates focused solely on timber and discussed its biodegradability and recyclability, or the impact deforestation has on the environment and wildlife. The fix is to go beyond timber, to metals, polymers and textiles, the way the backpack does, and to name the product every time.

A footprint also grows as a product travels. Product miles are every leg of its journey: from the raw material, to processing, to the factory, to the shop, to the user's home, and finally to disposal. A jumper never goes near a plane. Does it still have product miles, and why? Yes. Each journey by ship, lorry, train or van burns fuel and releases carbon dioxide. That is why it is product miles, not just air miles. Carbon is also produced during manufacture, because factories burn fossil fuels, directly or to make their electricity. Add it all up and you have a carbon footprint: the total carbon dioxide released by a product across its life, from getting its raw materials to its disposal. Carbon dioxide traps heat in the atmosphere, so a rising level can lead to global warming. Deforestation adds to it twice: felled trees that burn or rot release carbon dioxide, and fewer trees are left to absorb it. A pair of running shoes is made abroad and sold in the UK. Where across the shoes' life is carbon dioxide released? Walk every stage. Raw materials: crude oil is drilled for the synthetic rubber sole and the polyester upper. Processing: turning oil into rubber, foam and fibre takes a lot of energy. Manufacture: the factory's machines run on electricity, often from fossil fuels. Then the miles: to the factory, to a port, by ship to the UK, by lorry to a warehouse and a shop, then home. Every leg burns fuel. Use adds very little, since running shoes need no power. Disposal adds more, in landfill or by burning. Now the judgement: which stages could the designer most easily cut, and why? Making and moving them. That is where most of the carbon is, so fewer and recycled materials, and making the shoes nearer to where they are sold, cut the most. Read which stage a question names. One about producing a product wants making, not disposal; this one asked for every stage, so every stage was walked. The same examiner's report that warned about fair trade also records this: Many detailed responses were produced with an excellent analysis of the major issues and high-level personal evaluation. Common themes discussed were deforestation, mining, drilling, farming, product mile and greenhouse gas emissions. Those themes are this video's list, so the list works. The habit that goes with it is a named product for every theme, then your own judgement.

Shrinking a footprint starts with cutting it. Take spiral-bound paper notebooks. Paper is made from wood pulp, so every notebook needs trees felled. Now try this: what two steps could the maker take to cut deforestation? Use recycled paper, so less new timber is cut, though de-inking it still takes energy and water. And buy new fibre only from managed forests, where replanting keeps the forest, certified for example by the Forest Stewardship Council. The steel spiral adds a less obvious link: forests are also cleared to open iron ore mines. Even so, recycled paper does most to cut deforestation, and managed-forest paper is the fall-back where new fibre is needed for quality. Across any product, the same moves shrink the footprint: recycled materials, sourcing and making closer to the user, renewable energy in the factory, and less material. Carbon offsetting comes last. It means balancing the carbon dioxide a product still releases by paying for projects that take the same amount back. Those projects plant and protect forests, or fund wind and solar power, so less is released elsewhere. Done properly, it has three steps: measure the footprint, cut what can be cut, then offset what is left. A company that makes flat-pack desks calls them carbon neutral, because it pays a tree-planting scheme to cover all the carbon dioxide from making and shipping them. Does that make the desks' ecological footprint zero? Say why or why not. No. The emissions from building and moving the desks still go into the air today, while the new trees need decades to soak them back up, and could be felled or burn. And offsetting does nothing for the rest of the footprint: the forest felled for the chipboard, and the ore mined for the steel legs. It still has a place. It acts on carbon that is hard to cut quickly, like shipping, and the new forest gives wildlife a home. So offsetting is a fair last step, once the company has cut what it can, such as recycled chipboard, renewable electricity and more desks per lorry.

Check what has stuck now, from the whole definition to the board under your feet. What is a product's carbon footprint? The total carbon dioxide released across its life, from getting its raw materials to its disposal. Now another: a copper saucepan. Which route got its metal, and what harm can it do? Mining. Land is stripped and waste rock piled up, and nearby water can be polluted. Here's a different one: a factory paying low wages. Is that an ecological issue? No. Pay is about people, so it is a social issue. Ecological means land, water, air and wildlife. Now the skateboard you started with: which route made its maple deck, and what harm? Deforestation, unless the maple comes from managed forests. Habitats are lost, and fewer trees are left to absorb carbon dioxide.

If the four routes, product miles and offsetting all hang together, you've got this down, and a thumbs up spares you a rewatch. If they don't yet, save it, because this sort of thing often settles after a night's sleep.

Next in the chapter is Life cycle assessment, LCA. Hopefully that's next in your feed, but if not, search for ScholaFly D T oh seven, oh six.

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