Dozens of rows of furrows stand empty in a vast ploughed field in the Bolivian highlands. It should be full of potatoes ready for harvest, but frost and drought have had the upper hand in this region hit by climate change. Like many Aymara farmers in the area, Cristobal Pongo devoted his life to growing potatoes. "We harvest, we sell... It is our livelihood, our family's livelihood, for our children's education," explains the 64-year-old farmer, kneeling in his field at 4,000 metres above sea level. IMAGES AND SOUNDBITES