This is the second installment of a four-part series to be published each Wednesday on Action Needed to Stop Global Warming.
1. How Warm is Too Warm?
2. Worldwide Emissions Target
3. U.S. Emissions Target
4. Technologies to Get Us There
In Part 1 of this series, we described why scientists and policy-makers have identified the melting of the Greenland ice sheet, which would lead to a 20-foot rise in sea level, as the tipping point that must not be crossed. To stay below the tipping point, average global temperatures must not rise more than 3.6oF above pre-industrial temperatures, or 2.3oF above current temperatures.Today we consider how global emissions of greenhouse gases must change over the coming century to stay below that tipping point.