Green Options

In the constant push for ever newer and greener technology and energy, we sometimes forget that it is often both simpler and cheaper to revisit old techniques in new ways. And that’s exactly what a group of researchers in California has done.

Scientists have concluded that forests with excessive nitrogen concentrations reduce the amount of carbon dioxide released into the atmosphere. During a ten year study in Michigan by the National Science Foundation, researchers intentionally fertilized forests with two to three times the current levels of nitrogen. These levels mimic the predicted nitrogen levels of the near future due to fertilizers and exhaust from cars, power plants, and factories.

“It is pretty important to recognize that human effects on the nitrogen cycle have significant effects on climate,” said Alan Townsend, North American director of the International Nitrogen Initiative.

A new study by O.M. Aguilar, a graduate assistant in the Department of Horticultural Sciences at Texas A&M University, confirms what previous studies and parents know:  Gardening with children makes them more sensitive to environmental issues. As reported in LOHAS, the study found:

Test results indicated that children that had any type of experience with gardening had more positive attitudes toward the environment when compared with students that had not gardened. The study showed that hands-on gardening activities are important to the development of environmentally concerned citizens, and that children’s involvement in informal gardening experiences has as much impact on their environmental outlook as involvement in formal school-based programs.

It seems these days that you can’t get away from reading about carbon anywhere. From supermarket shelves to rental car counters, carbon labels and carbon offset offers are showing up everywhere. Part of this is because of the importance of and growing concern about global warming. But there’s another good reason: it’s a great single currency with which to compare the energy use and environmental impacts of very different kinds of activities and products. Pre-carbon, you had to use units like British thermal units (BTUs) or joules to compare the relative impacts of using gasoline to electricity or natural gas to fuel oil. Even then the calculations could be difficult and the results not very tangible to those of us who aren’t chemists. Carbon content makes it much easier. We can all envision carbon dioxide gas coming out of our tailpipes and smokestacks, so it’s tangible. And a carbon estimate allows you to quickly compare the relative environmental impacts of different product choices.

There is a price with this growing success, though: if you can’t measure the impact of something with carbon, then it can lose out in the court of public opinion. The environmental impacts of some items that are low (or unmeasurable) in carbon but high on other dimensions (water use, stormwater runoff production, etc) are often minimized. An increase in biofuels, for instance, might reduce the carbon content of motor fuels. But what if the biofuels are grown with intense nitrogen fertilizers that double the size of the summer dead zone in the Gulf of Mexico? Of what if we build 50 new nuclear power plants only to find that they exhaust regional supplies of fresh water for their cooling towers?

Now here’s an innovation that might make me consider moving back to New York City: air-purifying concrete. The small Dutch town of Hengelo is testing out the concrete paving stones, which contain a titanium-dioxide based additive that binds to nitrogen particles emitted by car exhaust and turns them into harmless nitrates.