The direct human costs of wars are so great that it might seem flippant to think about their environmental impacts. But modern armed forces are rapacious consumers of energy and kick out vast quantities of carbon – emissions that may contribute towards human harm well beyond the battlefield.
All carbon footprints are virtually impossible to pin down accurately, and this is especially the case for something as complex and chaotic as war. Indeed, the best that can be done in this case is to give some very crude numbers to provide a sense of scale.
At the time of writing the financial cost of the US military operation in Iraq since 2003 has been estimated at $1.3 trillion, with a further $600 billion anticipated for the lifetime healthcare costs of injured troops. Extrapolating from the carbon intensity of the health and defence industries in the UK, it’s possible to have a rough stab at converting this expenditure into carbon. This approach suggests that the US military operation in Iraq may have clocked up around 160–500 million tonnes of CO2e, plus a further 80 million tonnes for the healthcare of troops.
Add on a few per cent to both numbers to include the coalition forces and, say, another 1% for the footprint of the much more poorly resourced insurgency, and we might be looking at 250–600 million tonnes – roughly equivalent to everyone in the UK flying to Hong Kong and back between one and three times. And that’s excluding the direct emissions from explosions.