Oil, gas, timber, corn, slurry, ash. The list of natural resources that could provoke violent conflict in the coming decades is long, but one candidate stands out.

If climate change proceeds apace in the world's arid lands, geopolitical and natural resources experts say the potential for civil conflict over water resources is high. Especially in subsistence economies, water looms larger than oil as the indispensable resource.

In situations like Darfur many observers say the catastrophe can be attributed more to water scarcity than religious or cultural problems between an Arab Khartoum and an African south.

Resource expert Michael Klare specified that, though the world's leading powers are more likely to engage in conflict over oil, smaller states will see water conflicts that are "more frequent, more numerous, more widespread."

Further Reading:

International Alert consider 46 countries that could face violent conflict over water.

The Pacific Institute's data on water worldwide.

The link between water and conflict is debated thoroughly at Seed.