Global Warming. This is a HUGE HUGE HUGE topic. so I think I'll restrict myself to something specific...how about the effect of global warming on human fertility? These people found a strong inverse correlation between birth rate and increasing temperature. Wonder why the population of India is still increasing so fast, while Netherlands and Japan are in the negative...??

If you click on the above link, you'll get the PDF of the paper, published in an Elsevier journal called Medical Hypotheses (which has an impact factor of 0.920, for the uninitiated, thats at the bottom rung). See the paper's References and you'll realise that the quality of human semen has deteriorated over the past 50 years due to pollution...SHAME!!! SHAME!!!!