The UK Ministry of Defence has unveiled its sustainable procurement strategy in an effort to address climate change.
The strategy, which supports the defence acquisition reform programme, will look at ways in which the armed forces and their equipment can become more environmentally sustainable.
The strategy also aims to aid the MoD's acquisition processes by evaluating the adaptability of equipment and the ability to meet the challenges of climate change, and reduce the use of fossil fuels.
The MoD painted the hull of the aircraft carrier HMS Ark Royal with a special hydrodynamic paint to improve energy efficiency by 9% by reducing friction as the ship cuts through water.
The MoD engine upgrade for the Puma helicopters provides a 35% power boost to the aircraft, while improving energy efficiency by 25%
Minister for Strategic Defence Acquisition Reform Lord Drayson said that climate change, resource depletion and energy competition were likely to contribute to future instability and conflict, making sustainable procurement an important defence issue.
"Reducing reliance on fossil fuels and other scarce resources will help the armed forces address the causes of climate change," he said.
"It will also improve their ability to operate in hostile environments, reducing the need for resupply convoys in dangerous territory."