these indigenous bolivians are carrying out a ceremony, giving home-distilled alcohol to the pachamama -- the mother earth goddess. only if she gives her blessing will things take a turn for the better. alfonso blanco from the nature conservancy works with the people up here. he and his team are fighting against the effects of climate change in the mountains. down in the valley, clean water could run out. >> this lake is very important for the city of la paz, because it supplies water to almost fifty percent of its residents. right now we're waiting for the rainy season. as you can see, the lake's water level is very low, because the season's just beginning. >> we go higher up, to 4800 meters. this huge highland region in the hampaturi district is surrounded by six vast glaciers. and it provides clean water to people further down in the cities. >> the effect of climate change we're noticing most right now, and which the communities live with every day, is the lack of water. we're waiting for rain. this glacier is melting much more rapidly. that has a double effect. we have less snow an