The Link Between Tobacco and Cancer – whether or not this could be scientifically established
Star Wars – the space-based Strategic Defense Initiative and the science of nuclear winters
Acid Rain – sulphur and nitrogen emissions mixing with rain to become highly corrosive
The Ozone Hole – the idea that human activities were reducing the Earth’s protective ozone layer
The Effects of Secondhand Smoke – whether it caused cancer in otherwise healthy nonsmokers
Global Warming – whether it is being caused by CO2emissions released by burning fossil fuels