This is the third 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, I defined the global tipping point as the melting of the Greenland ice sheet, which could cause sea levels to rise 20 feet. In Part 2, I showed by how much global emissions of carbon dioxide (CO2) must drop to avoid this tipping point. They must start to decline around 2020, drop 50 percent by 2050, and drop at least 75 percent by the end of the century.
Meeting these global emissions targets will require a global effort. Even if the U.S. and other developed countries were to cut their emissions to zero, global emissions would likely exceed the targets by mid-century. This is because of the rapid rise in emissions from China and other developing countries.