By 2020, it is projected that between 75 and 250 million people in Africa will be exposed to increased water stress due to climate change. In some African countries, yields from rain-fed agriculture could be reduced by up to 50%.
The UK government-commissioned Stern Review on the Economics of Climate Change stated in 2006 that "Africa is facing the greatest catastrophe in human history".
Nigeria is one of the countries expected to be most affected by the impacts of climate change in Africa.
BBC World Service Trust producers Helen Bassey and Aro Leonard send these photo essays showing the impact of climate change on local communities in northern and eastern Nigeria.
In Imo State in the south east of the country, extreme rainfall has contributed to a level of erosion that has led to the destruction of houses, roads and forests. Click here to view the slideshow.
In northern Katsina State, desertification has uprooted many communities as the sand dunes take over what used to be fertile farm land. Click here to view the slideshow.
