Global energy security has become a pressing issue in the twenty-first century, with the available energy sources such as fossil fuels being threatened by exhaustion while their polluting effects remain a global concern. Modern economies rely heavily on oil, which is particularly affected by these considerations. World oil reserves are running out at an alarming rate, while the deposits being discovered in deep water are much more expensive to extract and call for much more advanced technologies than are currently possessed by most countries or oil companies. Although large reserves of coal remain, its use causes much more pollution, thus limiting it as an option. Along with these global energy security factors, energy demand has escalated, especially in the developing countries, and this trend does not seem likely to change soon. This puts the global economy at risk, so any country which can provide solutions will exercise more influence on world affairs, thus gaining an advantage in the race for global power.