Even with the best intentions, when humans intervene in the workings of nature, the combined effects of ignorance and arrogance can lead to great harm, and this third episode of Global Warning offers four sobering examples.
In the fight to control malaria, DDT had seemed like the final solution, but in fact the result has been to double the rate of infection. To control an invasive non-native snail introduced to a South Pacific island to satisfy French appetites, officials imported a snail-eating snail, which wiped out the native species instead.
Coffee plantations in Africa help feed a great global thirst, but the locals who grow and harvest the beans now live with lots of pesticides and below-subsistence wages. Thanks to highly efficient modern fishing operations, 70 percent of fish species are now fully exploited, overfished or depleted – and fishing boats all over the world don’t have anything to fish for.