President Barack Obama says he will seek vigorous climate-change policy. Efforts to curb greenhouse gases pose considerable economic pitfalls, as well as opportunities.

Despite a security clampdown in Baghdad, Iraq’s capital remains a hotbed of sectarian violence. The new government has yet to find a solution—military, political, or otherwise—for securing the city.

Sub-Saharan Africa suffers from greater levels of water stress than many other regions in the world. Experts say wise economic development focused on infrastructure and improved treaties on water all…