We are reminded that Earth Day is today. Two examples illustrate the meaning of this day. Established in 1970, Earth Day was originally intended "to inspire awareness and appreciation of the Earth's natural environment". This was a worthy objective considering our dependence on the natural ecosystems that sustain us all. Today is also the first anniversary of the explosion/sinking of the  Deep Water Horizon drilling platform that resulted in one of the biggest oil spills ever. This ...