Weather variability has increased in recent years due to climate change, causing severe environmental degradation and hampering farmers' activities. A number of agroecological methods are used to restore damaged ecosystems, and to replenish and manage natural resources such as water, forests, and soils. The Keita Project in Niger has restored deforested and degraded land through dunes reforestation, construction of water and wind management structures, and a variety of sustainable agriculture techniques. In addition to boosting agriculture and livestock production, the project has restored 45,000 hectares of woodland, and is credited for sequestering some 132,000 tons of CO2 per year. In Zimbabwe, Mr. Zephaniah Phiri Maseko has developed extraordinarily successful agroecological and water management techniques on his land. Dams, stone walls, plant diversification, and other techniques optimize the use of land and water, restoring soil fertility and stopping erosion. These techniques are now used by thousands of farmers across the country. Through the planting of fertilizer trees and shrubs, agroforestry projects in Mali, Malawi, and Cameroon increase nitrogen fixation in soils and reduce the use of synthetic fertilizers. Trees fertilize the soil, provide firewood, fruit, nuts, and medicine, preserve biodiversity and reduce forests degradation and stop erosion.