The conflict taking place in Darfur has many interwoven causes. On 16 June 2007, UN Secretary General Ban Ki-moon released a statement in which he proposed that the slaughter in Darfur was caused "at least in part from climate change", and that it "derives, to some degree, from man-made global warming". "The scale of historical climate change, as recorded in Northern Darfur, is almost unprecedented: the reduction in rainfall has turned millions of hectares of already marginal semi-desert grazing land into desert. The impact of climate change is considered to be directly related to the conflict in the region, as desertification has added significantly to the stress on the livelihoods of pastoralist societies, forcing them to move south to find pasture," the UNEP report states.
A meta-analysis of rainfall and other economic and population data, however, finds no correlation between rainfall patterns in Darfur and ethnic conflict there.
A point of particular confusion has been the characterization of the conflict as one between 'Arab' and 'African' populations, a dichotomy that one historian describes as "both true and false". It is important to distinguish the Sudanese Arab from other Arabs of the Middle East. Sudanese Arabs are descended primarily from the ancient Nubians. In terms of racial origin, it is not clear what specific racial or ethnic group the Nubians originated from. Over a period of centuries, Arab immigration into the Sudan, intermarriage among Nubians and Arabs, and the introduction of Islam and the Arabic language, Arabised the Nubians into the Sudanese Arab of today. In appearance, the Nubians look similar to the Ethiopians and Eritreans; at one point, they shared a common history with the latter.
In the late fourteenth or early fifteenth century, the Keira dynasty of the Fur people of the Marrah Mountains established a sultanate with Islam as the state religion. The sultanate was conquered by the Turco-Egyptian force expanding south along the Nile, which was in turn defeated by the Muhammad Ahmad, the self-proclaimed Mahdi. The Mahdist state collapsed under the onslaught of the British force led by Herbert Kitchener, who established an Anglo-Egyptian co-dominium to rule Sudan. The British allowed Darfur de jure autonomy until 1916 when they invaded and incorporated the region into Sudan.[25] Within Anglo-Egyptian Sudan, the bulk of resources were devoted toward Khartoum and Blue Nile Province, leaving the rest of the country relatively undeveloped.
The inhabitants of the Nile Valley, which had received the bulk of British investment, continued the pattern of economic and political marginalization after independence was achieved in 1956. In the 1968 elections, factionalism within the ruling Umma Party led candidates, notably Sadiq al-Mahdi, to try to split off portions of the Darfuri electorate either by blaming the region's underdevelopment on the Arabs, in the case of appeals to the stationary peoples, or by appealing to the Baggara semi-nomads to support their fellow Nile Arabs. This Arab-African dichotomy was exacerbated after Libyan President Muammar al-Gaddafi became focused on establishing an Arab belt across the Sahel and promulgated an ideology of Arab supremacy. As a result of a sequence of interactions between Sudan, Libya and Chad from the late 1950s through the 1980s, including the creation of the Libyan-supported Islamic Legion, Sudanese President Gaafar Nimeiry established Darfur as a rear base for the rebel force led by Hissène Habré, which was attempting to overthrow the Chadian government and was also anti-Gaddafi.
In 1983 and 1984, the rains failed and the region was plunged into a famine. The famine killed an estimated 95,000 people out of a population of 3.1 million. Nimeiry was overthrown on 5 April 1985, and Sadiq al-Mahdi came out of exile, making a deal with Gaddafi, which al-Mahdi did not honor, to turn over Darfur to Libya if he was supplied with the funds to win the upcoming elections.
In early 2003, two local rebel groups — the Justice and Equality Movement (JEM) and the Sudan Liberation Movement (SLM) — accused the government of oppressing non-Arabs. The SLM, which is much larger than the JEM, is generally associated with the Fur and Masalit, as well as the Wagi clan of the Zaghawa, while the JEM is associated with the Kobe clan of Zaghawa. Later that year, leaders of both groups, the Sudanese Government and representatives of the International diplomatic community were brought together in Geneva by the Center for Humanitarian Dialogue to look at ways of addressing the humanitarian crisis. In 2004, the JEM joined the Eastern Front, a group set up in 2004 as an alliance between two eastern tribal rebel groups, the Rashaida tribe's Free Lions and the Beja Congress. The JEM has also been accused of being controlled by Hassan al-Turabi.
On 20 January 2006, SLM declared a merger with the Justice and Equality Movement to form the Alliance of Revolutionary Forces of West Sudan. However, in May of that year, the SLM and JEM were again negotiating as separate entities.