With the Earth Day on the calendar, what better time to reflect upon a few of the calamities that we humans have visited upon the environment and ourselves. We would do well to remember that even the best of intentions can prove deadly when we become preoccupied with precaution and fail to contemplate the unintended consequences of our actions.

• Millions of acres of rainforest are fast disappearing as farmers in South America, Asia and elsewhere rush to clear land for cultivation. Among the culprits is government subsidization of corn-based ethanol — a supposed antidote to climate change. U.S. subsidies are expected to top $5 billion this year, which is prompting American farmers to devote more land to corn in place of soybeans. Consequently, their counterparts around the globe are clearing acreage to capitalize on higher prices for the displaced crops.

• Every 30 seconds, a child somewhere in the world dies of malaria, according to the World Health Organization. The disease claims more than one million lives each year, although it is both preventable and treatable. The principle means of prevention is control of malaria-bearing mosquitoes. Of the 12 pesticides currently recommended, DDT (Dichloro-diphenyl-trichloroethane) is widely recognized as the most effective. But in her book “Silent Spring,” Rachel Carson’s erroneous claims about the toxicity of DDT prompted the U.S. Environmental Protection Agency in 1972 to ban the pesticide, precipitating the suspension of spraying in dozens of countries — and the deaths of tens of millions of people.

• Tens of thousands of drivers and passengers have perished in crashes because of fuel economy standards. Specifically, government mandates to improve fuel efficiency have prompted automakers to produce smaller cars with lighter materials such as plastics, aluminum and fiberglass. But a 500-lb. reduction in vehicle weight increases crash fatalities between 14 per cent and 27 per cent annually, according to Harvard University and the Brookings Institution, among others. Moreover, cars weighing less than 2,500 lbs. account for two-and-a-half times as many crash fatalities as SUVs weighing 5,000 pounds or more, according to the U.S.-based Insurance Institute for Highway Safety.

• A cholera outbreak in Latin America killed more than 10,000 people and infected up to a million more after the government of Peru limited chlorination of the public water supplies — as demanded by Greenpeace and other environmental activists. The war on chlorine was abetted by the U.S. Environmental Protection Agency, which erroneously associated chlorination of water with an increase in cancer risk.

• Millions of pounds of apples were left to rot and family orchards were lost to foreclosure following reports that Alar, a common ripening agent, was the most potent cancer-causing compound in the food supply. The American Council on Science and Health later revealed that a child would have to drink more than 21,000 litres of apple juice every day for the rest of their life to consume the same amount of Alar fed to mice during tests for cancer.

Beyond these tragic missteps, laudable progress has been made in improving environmental quality. But it is not enough simply to say that along with the good comes the bad. The miscalculations that have cost so many lives were entirely foreseeable and wholly preventable. The value they offer us this Earth Day is as a reminder to reject zealotry and demand sound science in environmental policy; to reject scaremongering and demand facts from the media; and to resist the notion that government control of natural resources is necessarily more beneficial than the free exercise of property rights and the common law to protect the natural bounty that we hold so dear.