Tag Archives: environment

Saving ventilation cost by using the wind

Most large modern buildings have active ventilation built in, meaning that electric fans drive the air through the building. The airflow direction is usually fixed at construction time. However, if the wind happens to blow from the opposite direction to the ventilation flow, then the fans require extra energy to counter the wind. On the other hand, if the wind agrees with the airflow in the building, then the fans may not need to be run at all. To save electricity, a building could have a wind direction sensor (a weather vane) on the roof connected to a switch that reverses the ventilation fans, so that the fans always pump air in approximately the same direction as the wind. If the wind is strong enough, a wind speed sensor (a small windmill or windsock) on the roof could stop the ventilation fans altogether.
The tradeoff for this adaptive ventilation system is the initial fixed construction cost and the ongoing maintenance of the weather vane, windsock and controller of the fans. All the extra components of the system (relative to the current unidirectional ventilation) are cheap and robust, so the both the fixed cost and the maintenance should be negligible.
Current ventilation systems have differently shaped air inlets and outlets in the rooms, which suggests that the system requires a particular airflow direction. In this case, adaptive ventilation may be much more expensive than the current ones, because the ventilation shafts and air vents need to be doubled. To avoid the need to build twice as many shafts and vents, have just the air inlets and outlets of the whole building switch roles with the wind direction. The rest of the system can remain unidirectional when the valves from the building’s inlet and outlet to the rest of the system switch appropriately. The air inside the building can then move in the opposite direction of the wind some of the time. In this case, the electricity saving is only realised if the building is sufficiently airtight, which is the case for modern highrises that have unopenable windows. If the air is allowed to move through the building independently of the ventilation and the wind is opposite the airflow in the system, then the fans have to overcome the air pressure difference like in the current systems. This wastes electricity.

Poaching reduction using lab-grown ivory

Poachers kill elephants for tusks and rhinos for horns because these can be sold for a high price on the black market. The killing has occurred both in the wild and in zoos, and thieves have broken into nature museums to steal rhino horns from exhibits. Sometimes news reports describe how police crush or burn seized illegal ivory, which seems counterproductive, because it reduces supply and thus drives up the price. A higher price increases future poaching. Perhaps the police are in the pay of some illegal ivory dealers and are deliberately helping drive up the price by destroying competing dealers’ products.
Instead, the price of ivory and rhino horn should be reduced so that poaching becomes unprofitable. Many organs have been grown in the lab using a collagen scaffold seeded with stem cells from the appropriate tissue (bladder, skin, heart). Growing elephant tusks or rhino horns in the lab should be feasible using similar techniques. Flooding the market with cheap lab-grown horns and tusks would eliminate the incentive to poach.
The demand for ivory and rhino horn is mostly due to silly beliefs about their medicinal properties, so the buyers may not want lab-grown substitutes, believing these to be ineffectual (which these are, just like wild-type horns and tusks). In this case, the lab-grown horns and tusks should be made indistinguishable from animal-derived ones and inserted into the illegal supply chain covertly. The dealers on the black market are not too honest people and would probably be happy to lie to their customers that lab-grown products are from wild animals.

Local and organic food is wasteful

The easiest measure of any good’s environmental impact is its price. It is not a perfect measure. Subsidies for the inputs of a product can lower its price below more environmentally friendly alternatives that are not favoured by the government. Taxes, market power, externalities and incomplete information can similarly distort relative prices, as introductory economics courses explain. However, absent additional data, a more expensive good likely requires more resources and causes more environmental damage. Remembering this saves time on debating whether local non-organic is better than non-local organic fair trade, etc.

Local and organic are marketing terms, one suggesting helping local farmers and a lower environmental impact from transport, the other claiming health benefits and a lower environmental impact from fertilizers. Organic food may use less of some category of chemicals, but this must have a tradeoff in lower yield (more land used per unit produced) or greater use of some other input, because its higher price shows more resource use overall. From the (limited) research I have read, there is no difference in the health effects of organic and non-organic food. To measure this difference, a selection bias must be taken into account – the people using organic are more health-conscious, so may be healthier to start with. On the other hand, those buying organic and local may be more manipulable, which has unknown health effects. Local food may use less resources for transport, but its higher price shows it uses more resources in total. One resource is the more expensive labour of rich countries (the people providing this labour consume more, thus have a greater environmental impact).

If one wants to help “local farmers” (usually large agribusinesses, not the family farms their lobbying suggests), one can give them money directly. No need to buy their goods, just make them a bank transfer and then buy whichever product is the least wasteful.

There are economies of scale in farming, so the more efficient large agricultural companies tend to outcompete family farms. The greater efficiency is also more environmentally friendly: more production for the same resources, or the same production with less. Helping the small farms avoid takeover is bad for the environment.

Fair trade and sustainable sourcing may be good things, if the rules for obtaining this classification are reasonable and enforced. But who buying fair trade or sustainable has actually checked what the meaning behind the labels is (the “fine print”), or verified with independent auditors whether the nice-sounding principles are put into practice? When a term is used in marketing, I suspect business as usual behind it.