It’s hard to be environmentally conscious these days. It’s not as simple as getting people to recycle. Today’s biggest challenges are often in conflict with each other.
In deciding how best to meet the world’s growing needs for energy, the answers depend crucially on how the question is framed. Looking for the most cost-effective path provides one set of answers; including the need to curtail greenhouse-gas emissions gives a different picture. Adding the need to address looming shortages of fresh water, it turns out, leads to a very different set of choices.