The impact of a change in the ecological conditions, like the introduction of the pesticide DDT, can cascade through an ecosystem with wierd and unexpected consequences. Richard Fagerlund explains:
In the 1950s, the World Health Organization sent supplies of DDT to Borneo to fight mosquitoes that spread malaria among the people. The mosquitoes were quickly wiped out. But billions of roaches lived in the villages, and they simply stored the DDT in their bodies.
One kind of animal that fed on the roaches was a small lizard. When these lizards ate the roaches, they also ate a lot of DDT. Instead of killing them, DDT only slowed them down. This made it easier for cats to catch the lizards, one of their favorite foods.
About the same time, people also found that hordes of caterpillars had moved in to feed on the roofing materials of their homes. They realized that the lizards that previously had kept the caterpillar population under control had been eaten by the cats. And now, all over North Borneo, cats that ate the lizards died from DDT poisoning. Then rats moved in because there were no cats to control their population. With the rats came a new danger: plague. Officials sent out emergency calls for cats. Cats were sent in by airplane and dropped by parachute to help control the rats.
Groundwater tends to be a common property resource. In places like Yemen, where ownership rights are not clearly defined it tends to be overexploited. So much so, that they’re looking at running out within the next 10 years. Peter Salisbury has an article in Foreign Policy.
Most potable water in Yemen is produced from a series of deep underground aquifers using electric and diesel-powered pumps. Some of these pumps are run by the government, but many more are run by private companies, most of them unlicensed and unregulated. Because of this, it is nigh on impossible to control the volume of water produced. By some (conservative) estimates, about 250 million cubic meters of water are produced from the Sanaa basin every year, 80 percent of which is non-renewable. In recent years, the businessmen who produce the water have had to drill ever-deeper wells and use increasingly powerful pumps to get the region’s dwindling water reserves out of the ground.
Nuclear disasters are so rare that they’re easy to forget about when we’re talking about the right mix of alternative (non-carbon based) energy sources for the future.
Right after the accidents at Three Mile Island in 1979 and Chernobyl in 1986, awareness of the dangers lead to a de facto moratorium on nuclear power plants in the U.S.. This was good in that people were now treating nuclear power much more respectfully, and incorporating the costs of potential accidents into their calculations. However, it also reduced the interest and effort of developing newer and safer types of nuclear plants.
We’ll have this discussion next year when we focus more on the physical sciences.
A recent study making the news today, warns about the risks of energy drinks. 30-50% of adolescents and young adults drink them, they have lots of caffeine and other additives, and they do not have a whole lot of benefits.
Energy drinks have no therapeutic benefit, and many ingredients are understudied and not regulated. The known and unknown pharmacology of agents included in such drinks, combined with reports of toxicity, raises concern for potentially serious adverse effects in association with energy-drink use.
–Sara Seifert et al., 2011: Health Effects of Energy Drinks on Children, Adolescents, and Young Adults
Where facts exceed curiosity, we end up relying on symbols and symbolic language that are weighted with emotional meaning that are detached from ideas, according to Walter Lippmann as described by Geoffrey Nunberg on On The Media this weekend.
I think you can see this fairly clearly with adolescents. When they lack the interest, motivation, curiosity and information they tend to resort to slogans and cliché’s instead of looking up information or making thoughtful, logical arguments.
It also may be a marker for cognitive development, though interestingly, in my experience, it seems that more abstract thinking leads to less use of symbology and more reasoning. Partly, I suspect, its because they’re also acquiring the language to express more complex ideas, but adolescent education needs to include lots of opportunities for logically taking apart symbols.
I’ve started a pattern in class that I’ve noticed students picking up with each other.
If someone says something like, “It was good,” I ask, “Why?”
If they say, “I liked it,” I say, “Because?”
Often the first answer is along the lines of, “Because it was good,” but persistence with the whys’ and becauses’ will usually lead to some actual information and ideas. Over time, the mining process gets easier as students come to expect it and realize what you’re aiming for.
CO2 emissions by Planes or Volcano, by David McCandless
David McCandless’ graphic showing the amount of CO2 emitted by the European airline industry compared to the amount emitted by the volcano that shut down that industry for several days is beautiful in its simplicity. It seems that despite the fact that volcanoes emit a lot of CO2, the volcanic eruption reduced total emissions of carbon dioxide into the atmosphere.