With food prices skyrocketing and climate change looming, the world needs a green revolution like the one a generation ago. But many valuable seed varieties have been lost ”“ and scientists now are scrambling to protect those that remain before they vanish down the genetic drain.

Paul Ehrlich still believes that overpopulation imperils the Earth’s
future. But the good news is we are approaching a demographic turning
point: Birth rates have been falling dramatically, and population is expected to peak later this century — after that, for the first time in modern history, the world's population
should actually start to decline.

As the Arctic's sea ice melts, energy and mining companies are moving into previously inaccessible regions to tap the abundant riches that lie beneath the permafrost and the ocean floor. The potential environmental impacts are troubling.

The burgeoning amount of carbon dioxide in oceans is affecting a lot more than coral reefs. It is also damaging marine life and, most ominously, threatening the future survival of marine populations.

When it comes to setting climate change policy, science can only tell us so much. Ultimately, a lead report author for the Intergovernmental Panel on Climate Change writes, it comes down to making judgments about what is fair, equitable, and just.