Next month, a scientific committee sponsored by the United Nations will put out its latest assessment of climate change. The report is expected to underscore yet again that climate change is a serious problem and human beings are largely responsible.
"If you could imagine a grandfather clock and see the pendulum swinging back and forth, ideally that pendulum would swing back and forth very uniformly," Ludlow says. "Each swing would take exactly the same amount of time."
That's stability. But what if something perturbs the system, like a mischievous toddler?