Teacher's edition.

• Author: Rebhun, Elliot

As we move into 2010, our cover story looks at some of the most critical international challenges facing President Obama and the nation, from China's rise as a global power to the nine-year-old war in Afghanistan and the long-term threats posed by global warming.

Speaking of global warming, your students may be surprised--as we were--to learn how big an impact the foods we eat have on the environment. As "Is Your Lunch Causing Global Warming?" explains, our diets may have an even greater effect on climate change than our cars and the industrial pollution we hear so much about.

This spring, the Supreme Court is expected to rule on a momentous case involving teen rights: Do life sentences without the possibility of parole for juvenile offenders violate the Eighth Amendment's prohibition against...