Mali - Climate

Mali is located in western Africa at a latitudes of 10 to 25�N, straddling the sub-tropical band called the Sahel. The northern parts of Mali reach well into the dry Sahara desert, while the southern regions experience a wetter, more tropical, climate.The seasonal rainfalls in Mali are controlled by the movement of the tropical rain belt (also known as the Inter-Tropical Conversion Zone, ITCZ) which oscillates between the northern and southern tropics over the course of a year, and brings rainfall to the southern regions of Mali when it is in its northern position between June and October, peaking in August. The average rainfall in the wettest (southernmost) regions at this time is an average 300mm per month, but rainfall totals diminish rapidly with increasing latitude. In the dry months between November and March, almost no rain falls at all. Variations in the latitudinal movements of the ITCZ from one year to another cause large inter-annual variability in wet-season rainfall, which means that Mali suffers from recurring drought. The northern, desert regions of Mali receive very little rainfall all year round.

Like much of the Sahel, Mali is experiencing frequent droughts and significant variability in rainfall. Climate change is expected to increase temperatures, rainfall variability, and the magnitude of extreme weather events such as drought. With more than 80 percent of Mali�s population found to be dependent on rain-fed agriculture for their livelihood, they are extremely vulnerable to the impacts of climate change.

Mali's economy is essentially based on the exploitation of natural resources. The growth demographic (3.6% / year) and climatic constraints have led to overexploitation and degradation of these resources. Two-thirds of the country is arid and semi-arid dominated by the problems of desertification. Natural risks have increased with the intensification of climate change: Recurrent droughts, floods, strong winds, bush fires, destabilization of the rain regime. The agriculture which is the most affected represents 45% of the GNP and occupies approximately 80% of the active population. This situation is all the more serious since the climate scenarios for 2100 forecast on average a 3 � C increase in temperatures and a 22% decrease in rainfall across the country.

The climate of Mali, of Sahelian type, is characterized by inter and intra annual variability of climatic parameters and the intensification of droughts since 1970. This situation is exacerbated by the fragility of ecosystems and production systems (agriculture, livestock, fishing, forestry, etc.), by the needs of population growth and by socio-social constraintseconomic, making the country very vulnerable and weakening its adaptive capacity. In order to ensure sustainable development, measures to adapt to climate change are essential in all sectors of development. It is in this context that Mali has developed several policies, strategies and action plans. (table below) incorporating national guidelines on adaptation with reference to Strategic Framework for Growth and Poverty Reduction (CSCRP). These programs are being revised in order to develop the National Adaptation Plan (PNA) of the Mali to climate change by 2030 to better orient and coordinate actions.

Rainfall in Mali declined rapidly between 1950 and the mid-1980s, partially recovered in the 1990s, then declined slightly in the 2000s. The 2000�2009 average remained about 12 percent lower than the 1920�1969 mean (�1.1 standard deviations). Rainfall increases since the mid-1980s are probably caused by the warming of the north Atlantic Ocean (Hoerling and others, 2006). These changes can be visualized in three ways: as a reduction of the region receiving adequate rainfall for viable agricultural livelihoods, as maps of anticipated changes in rainfall, and as time series plots.

Mali receives most of its rain between June and September, and rainfall totals of more than 500 millimeters (mm) during this season typically provide enough water for crops and livestock. Between 1960 and 1989, the region receiving (on average) this much rain during June�September. During the past 20 years, this region has retreated slightly southward. Rainfall decreases range from -150 to -10 mm across a large part of the country, with the largest decreases found in the west of the country. Observed changes (those between 1960 and 2009) account for 63 percent of the change magnitudes.

Smoothed time series of 1900�2009 rainfall, extracted for crop growing regions in Mali, show that 2000�2009 rainfall has been, on average, about 12 percent lower than rainfall between 1920 and 1969. These time series were based on crop growing regions in southwestern Mali (Kayes and Koulikoro) and southeastern Mali (Mopti, Segou, Sikasso). In both southwestern and southeastern Mali , rainfall has recovered since the mid-1980s, but has leveled off during the past decade, and 2000�2009 rainfall remains substantially below its 1920�1960 mean.