South Korea Turns Off the Lights

One Wednesday a Month, offices in South Korea will shut off their lights early in the evening. No, they're not trying to look like North Korea when viewed from space. Instead, they want all their office workers to go home.

Why? Well, I've written how some countries have high birth rates that lead to food and resource shortages. South Korea has the opposite problem, with the world's lowest birth rate. At only 1.2 kids per couple, their population is actually in decline. This means that a comparatively large portion of the population are elderly, and there will be greater pressure on people of working age. And of course with less workers, the country has less manufacturing capacity. Therefore, the Ministry of Health hopes that by getting people out of the office, they might go into the home and make babies.

In order to make this truly successful, I think that the government also needs to shut down all TV broadcasts on those same evenings, at least based on the Indian government's assumption that getting people to watch television at night will stop them from making babies.

Using White to Decrease the Red

As anyone who has stepped barefoot on a sunny day from a concrete surface to a slate one knows, dark colors get really hot. Since white surfaces reflect more of the sunlight's energy, using light-colored roofs can reduce air conditioning needs and expenses. How much? 20% in hot, sunny weather, says an article in the New York Times. Cumulatively, this could have a big effect.

Turning all of the world’s roofs “light” over the next 20 years could save the equivalent of 24 billion metric tons in carbon dioxide emissions. “That is what the whole world emitted last year,” Mr. Rosenfeld said. “So, in a sense, it’s like turning off the world for a year.”

What about locations where there's little AC load, and you want the sun's heat in the winter? For one, there's far less sunlight in winter (that's why it's winter), so the unhelpful 'loss of solar gain' in the winter is less than the beneficial loss in the summer. Even so, having light roofs in Sweden or Alaska is probably not a good idea.

The extra heating costs may outweigh the air-conditioning savings in cities like Detroit or Minneapolis. But for most types of construction, they say, light roofs yield significant net benefits as far north as New York or Chicago. Although those cities have cold winters, they are heat islands in the summer, with hundreds of thousands of square feet of roof surface absorbing energy.

By the bye, I will be on vacation next week, so a little break from posts.