LiveScience: Climate change might have helped bring about the fall of the ancient Khmer civilization in Angkor, Cambodia, nearly 600 years ago, new research suggests. Historians have given various explanations for the fall of the empire that stretched across much of Southeast Asia between the ninth and 14th centuries (801 to 1400), from land overexploitation to conflict with rival kingdoms. But the new study offers strong evidence that two severe droughts, punctuated by bouts of heavy monsoon …