from the African Journal of Ecology summarized the environmental changes that species faced after the late 20th century droughts, some of which includes (but is not limited to) severe declines in biodiversity and increases in other disturbances, such as fires. 21st century droughts 2010 Sahel drought Throughout June to August 2010, famine struck the Sahel. Niger's crops failed to mature in the heat which resulted in famine. 350,000 faced starvation and 1,200,000 were at risk of famine. In Chad, the temperature reached on June 22 in Faya-Largeau, breaking a record set in 1961 at the same location. Niger tied its highest temperature record set in 1998, on also June 22, at in Bilma. That record was broken the next day, on June 23 when Bilma hit . The hottest temperature recorded in Sudan was reached on June 25, at in Dongola, breaking a record set in 1987. Niger reported diarrhoea, starvation, gastroenteritis, malnutrition and respiratory diseases killed and sickened many children July 14. The new military junta appealed for international food aid and has taken serious steps to calling overseas help since coming to office in February 2010. On July 26 the heat reached near-record levels over Chad and Niger. 2012 Sahel drought By the middle of 2010, another drought in the western Sahel was predicted by several organisations for 2011 and 2012. Potential contributing factors Originally it was believed that the drought in the Sahel primarily was caused by humans over-using natural resources in the region through overgrazing, deforestation and poor land management. In the late 1990s,climate model studies suggested that large scale climate changes were also triggers for the drought. Based on Senegal river cycles, precipitation cycles of various El Sahel stations which are related to Solar (89–120 years) Wolf-Gleissberg cycles, and on relations to Nile floods and Equatorial lake levels, Yousef and Ghilly in 2000 anticipated that there is a considerable probability that drought will occur El Sahel Zone in 2005±4 years. This forecast was correct as drought occurred in El Niger in 2005 and again in 2010. In 2002, after the phenomenon of global dimming was discovered, a CSIRO study suggested that the drought was probably caused by air pollution generated in Eurasia and North America, which changed the properties of clouds over the Atlantic Ocean, disturbing the monsoons and shifting the tropical rains southwards. In 2005, a series of climate modeling studies performed at NOAA