They burn to clear land to farm corn and coffee.
They burn the rain forest to make way for cattle.
And in the jungle of the Peten, not far from the Mayan temples of Tikal, some 37,000 acres of national forest burn every year for agriculture and mining.
"A long time ago there was a huge forest here with big trees," remembers Blas Cuz, a farmer in Guatemala. "Now, those forests are gone. We have to walk farther and farther for wood."