After many years of debate, Hong Kong has finally decided to impose a 50 cents (USD 0.06) tax on the use of disposable plastic bag in supermarkets. There have been many efforts to convince people to reduce plastic bag use voluntarily. But mostly the shops hand out bags freely and the result is very limited.

I was shopping in a Causeway Bay supermarket in the basement of a Japanese department store. To see how effective this law is, I've spent a few minutes to observe the shoppers coming out from the cash register. The ratio of people using their own reusable bag vs. disposable plastic bag is roughly half and half. I was hoping even more people would bring their own bag. But compare to the baseline figure a few years ago where reusable bag usage is almost 0, this is certainly a big improvement.

See also my eariler entry about proposed plastic bag ban in California.

2010.06.28 [environment] - comments

I'm delighted to hear that the California legislature is consider to ban the use of plastic and some paper bags from retails. If the law passes, we will be joining other nations like Ireland and China in curbing irresponsible use of disposables and reduce the pollution to the environment.

Three years ago, over the objection of California Grocers Association, San Francisco was the first city in California to ban the use of plastic bags in large stores. Like many progressive ideas sprout from this city, it seems too radical to some people at the time. Business groups opposed and loud mouthed critics spare no effort to ridicule San Francisco. But time and again, what appear as crazy ideas at the beginning get wide acceptance eventually. Remember things like recycling and gay right. Before they get wide acceptance today, they were fiercely opposed and ridiculed at the beginning. After San Francisco, a few cities like Oakland quickly joined to ban plastic bag. Finally it spreads to the entire state. This time the California Grocers Association has turned around to support the registration. It only take them 3 years!

The final opponent to this bill is none other than the plastic industry. I want to take aim at their fallacious claim this will result in higher prices to consumers. The most important point is the cost of disposable bags will be trivial compare to cost of goods. That's why retails are willing to hand out bags freely in the first place. But if the ban of plastic bag has any effect on price at all, it should lower it. 'Free' plastic bags are after all, not free. Their cost are just part of the retailer's business cost and will be reflected in the price.

If I'm plastic bag manufacturers, I would consider switching gear to other high value product like tote bags, which can sell for $10 or more. Why be the bad guy producing millions of plastic bags at low margin and pollute the environment? Stop making product for pennies and start making high margin product! It is good for your bottom line and it is good for your karma.

2010.06.02 [environment] - comments

The idea of green roof is attractive. In many buildings, roofs are wasted space cover with black asphalt. Why not turn it into something more useful by covering it with soil and grow vegetation on top of it? This will help reduce rain water runoff, urban heat island effect, air-conditioning cost as well as CO2 in the atmosphere.

One great example of green roof project is in the GAP building in San Bruno, California just south of San Francisco. (GAP has since moved out. Google/YouTube is the current tenant.) The office building has sloped roofs that are covered extensively with vegetation. I happen to work in the area and know about the building.

Can green roofs significantly improve the environment? One day I was glancing at an aerial image. I can't help but notice that GAP building's green roof covers only a tiny percentage of the land in San Bruno's office area, as you can see in the green circle I have marked below.

I went ahead and did a little study. I classified the area into four categories: 1) Buildings (red); 2) Natural Area (Green); 3) Parking lot (Yellow); 4) Roads (grey). For simplicity, some small amounts of landscaped areas are counted as parking lot.

I measured the proportion of area of each category as below

• 17% Building
• 10% Natural area
• 55% Parking lot
• 18% Road

In fact buildings only cover 1/6 of land in the area. Roads use as much land as the buildings. Parking lots occupy a staggering 55% of the land. That is over half of the land and three times as much area as the building themselves! Instead of green roof, perhaps what we really need are green parking lots!

Of course this is just one example taken from a suburban environment. And this is not to diminish the value of green design adopted by the GAP building. In fact you can easily see from the picture that GAP uses land far more efficiently that other nearby office complexes. This is just a clear example to me that by far the biggest ecological issue in a suburban commercial space is its extensive asphalt parking lot. And there is probably where designers should spend more effort in greening.

2009.02.14 [environment] - comments