birds , not to mention more than 20 million people living out of Lake Chad -- fisherpeople , farmers . '' `` It would be a human disaster , a tragedy , '' he said . `` In this case we have people who are the poorest of the poor . '' `` In addition to an approximately 60 percent decline in fish production , there has been degradation of pasturelands , leading to a shortage of animal feed estimated at 45 percent in certain places in 2006 , reduction in livestock and biodiversity , '' the agency said . The disappearance of the lake is being caused by climate change , population pressure and natural variations in climate , the FAO said . Two rivers which feed the lake , the Chari and Logone , have been significantly reduced in the past 40 years , the agency said . The organization will unveil the results of a study into the diversion of the Oubangui river in an effort to help Lake Chad at a conference , `` Saving Lake Chad , '' in Rome , Italy , on Friday . `` Water transfer is not a new thing ,
-LRB- CNN -RRB- -- Up to 30 million people are facing `` a humanitarian disaster '' as one of Africa 's biggest lakes shrinks , a United Nations agency warned Thursday . Porters remove goods from a boat on Lake Chad in 2007 . Lake Chad was about the size of Maryland -- bigger than Israel or Kuwait -- in 1963 , satellite images show . By 2001 , it covered less than one-fifth of that area -- making it smaller than Delaware or Mauritius . The drying-up of the shallow lake is fueling conflict and migration , the U.N. 's Food and Agriculture Organization said . Once one of the biggest bodies of water in the world , it could disappear entirely in about 20 years , the FAO said , citing forecasts from the U.S. National Aeronautics and Space Administration . `` If that happens it 's going to be a disaster , '' Parviz Koohafkan , director of the Land and Water Division of the FAO , told CNN by phone from Rome . The Lake Chad basin is `` one of the most important agriculture heritage sites in the world -- the biodiversity , the migratory