[!□] □ | □
[!□=□] □ | □
[!(□ & □)] □ | □
The root causes of environmental change have both natural and humanmade factors , and include interactions between them . Regional lobbying is needed to support the efforts of African governments in persuading developed countries to open up their markets , and to eliminate subsidies on agriculture , textiles and other export products competing with those of the region . This reduces water availability and quality and contributes to coastal erosion , exacerbating the impacts of climate change on freshwater resources and of sea level rise . These reforms aimed at restoring balances in the economy and at creating a basis for sustainable growth by liberalizing key markets from excessive state control . Further policy support is needed to accelerate technology development , boost markets , and provide economic incentives to offset start-up costs ( Salwin 2004 ) . There are now over 117 000 protected areas worldwide , taking into account both those classified under any of the six IUCN management categories I to VI ( see below ) , and those not classified . Similarly , regional and international support is needed to persuade the developed countries to remove agricultural subsidies which are currently blocking entry of African agricultural products into their markets , and which are encouraging the dumping of products onto the African market . Children , older people , and those with existing respiratory illnesses are also more vulnerable . These have particularly serious consequences for Africa because of the difficulties experienced in the region in predicting their occurrence and in mitigating their effects , and also because many African countries lack the financial resources to make adequate and timely recovery before the next climatic event . Non-toxic and clean-burning dimethyl ether ( DME , sometimes called ‘ synthetic LPG ’ ) shows promise as a clean non-toxic fuel that can meet the same markets now served by LPG .