Thus, the role of the drought in augmenting pre-existing internal migration, and the role of the distress migration in accentuating demographic, economic and social pressures in receiving areas, remain contested. Estimates of the number of people who abandoned their farms in response to the drought range from less than 40,000-60,000 families  to more than 1.5 million displaced . However, the numbers have to be seen in the context of prevailing population growth, significant rural-urban migration, and the preceding inflow of around 1.5 million refugees from neighbouring Iraq . In addition, research suggests that the migrants played a peripheral role in the initial social mobilisation in March 2011 .
IPCC
Climate Change 2022: Impacts, Adaptation and Vulnerability
IPCC Report