Growing up in a village in Burkina Faso, Georges Bazongo remembers his parents and neighbors cutting down trees each year to expand their farmland so they could "grow enough food for our families to eat."

He also noticed some trees becoming drier in the drought-prone region, an indication too that the soil was deteriorating as heavy rains washed away its fertile layer.

Some of his relatives moved to Cote d'Ivoire in search of a better life, said Bazongo, 48.