Wielding machetes and calipers, sweat-soaked scientists count carbon in Amazon

The machete-wielding scientists ventured into the Amazon, hacking through dense jungle as the mid-morning temperature soared past 100 degrees Fahrenheit (38 C). Soaked in sweat, the small group of men and women sawed and tore trees limb from limb. They drilled into the soil and sprayed paint across tree trunks. This is vandalism in the name of science - part of an effort to measure more precisely how much greenhouse gas is absorbed by different types of forests in the Amazon basin.