Without action, the overall costs of climate change will be equivalent to losing at least 5% of global GDP each year. The estimated annual cost of achieving stabilisation between 500 and 550ppm CO2 equivalent, currently at just over 400ppm, is 2% of GDP. In a survey of 59 Sub-Saharan Africa countries, 33 were classified as highly or moderately highly vulnerable to climate change. All 59 were ranked in the lowest quintile on their adaptive capacity to climate change. Land degradation: a decline in the capacity of the land to supply human needs, whether of food or other products and services. Between 1981 and 2003 a quarter of the global land area has been degraded, most notably in Africa, south of the equator, Indochina, Myanmar and Indonesia.
Globally land degradation affects 1.5 billion people and over 40% of the very poor live in degraded areas.
An increase of 1 ton per hectare of soil carbon in degraded croplands can increase maize yields by 200 to 300kg/ha, wheat by 20 to 40kg/ha and rice by 20 to 50kg/ha. Conservation agriculture: comprises various systems of reduced or no tillage farming.