Fertilizer is also increasingly unavailable because Western environmental groups have fought to end its use due to environmental concerns. The Green Revolution pioneers Norman Borlaug and Keith Rosenberg cited as the obstacle to feeding Africa by . Future threats
In the future, variety of factors could potentially disrupt global food supply and cause widespread malnutrition. Global warming is of importance to food security. Almost all malnourished people (95%) live in the tropics and subtropics, where the climate is relatively stable. According to the latest Intergovernmental Panel on Climate Change reports, temperature increases in these regions are "very likely." Even small changes in temperatures can make extreme weather conditions occur more frequently. Extreme weather events, like drought, have a major impact on agricultural production, and hence nutrition. For example, the 1998–2001 Central Asian drought killed about 80 percent of livestock in Iran and caused a 50% reduction in wheat and barley crops there. Other central Asian nations experienced similar losses. An increase in extreme weather such as drought in regions such as Sub-Saharan Africa would have even greater consequences in terms of malnutrition. Even without an increase of extreme weather events, a simple increase in temperature reduces the productivity of many crop species, and decreases food security in these regions.Another threat is colony collapse disorder, a phenomenon where bees die in large numbers. Since many agricultural crops worldwide are pollinated by bees, colony collapse disorder represents a threat to the global food supply.
Melanonychia is a black or brown pigmentation of the normal nail plate, and may be present as a normal finding on many digits in Afro-Caribbeans, as a result of trauma, systemic disease, or medications, or as a postinflammatory event from such localized events as lichen planus or fixed drug eruption. : 790 : 665 There are two types, longitudinal and transverse melanonychia. : 671  Longitudinal melanonychia may be a sign of subungual melanoma (acral lentiginous melanoma), although there are other diagnoses such as chronic paronychia, onychomycosis, subungual hematoma, pyogenic granuloma, glomus tumour, subungual verruca, mucous cyst, subungual fibroma, keratoacanthoma, carcinoma of the nail bed, and subungual exostosis. See also
Nail anatomy
List of cutaneous conditions


== References ==