San Francisco Chronicle: In his inaugural address, President Obama made climate change a priority of his second term. It may be too late.
Within the lifetimes of today's children, scientists say, the climate could reach a state unknown in civilization.
In that time, global carbon dioxide emissions from burning fossil fuels are on track to exceed the limits that scientists believe could prevent catastrophic warming. CO2 levels are higher than they have been in 15 million years.
The Arctic, melting rapidly and probably...