soil erosion, deforestation, biodiversity, salination, climate change, urbanization, global warming, forestation, eutrophication, malnutrition, afforestation, arid, undernutrition, droughts, malaria, salinity, sahel, overexploitation, acidification, denudation, reforestation, schistosomiasis, industrialization, sedimentation, guinea worm disease, urban sprawl, silting, agroforestry, bilharzia, trypanosomiasis, hydrological, cropland, undernourishment, degradation, underdevelopment, glaciers, urbanisation, dieback, marginalization, acid rain, famine, grasslands, ecosystems, ecological, epidemics, graisse, aral sea, pastoralism, subsidence, semiarid, depletion, herders, hunger, scarcities, onchocerciasis, river basin, overpopulation, desiccation, deserts, erosion, biome, quaternary period, hydrologic cycle, overfishing, trachoma, sudd, depopulation, semidesert, floods, pauperization, tsetse, striga, pollution, volcanism, peatland, root rot, wmo, hydric, halophyte, coastland, herdsmen, biopiracy, cowpea, water hyacinth, eastern ghats, shrubland, desalinisation, inundations, malnourishment, civilizations, fireweed, tagal, deltaic, freshwater, sodic, submergence, habitats, kara kum, pesticide poisoning, poverty, starvation, diseases, destabilization, commercialization, internationalization, militarization, warming, attrition, democratisation, disinvestment, feminization, flooding, impoverishment, slowdown, commodification