Off-roaders often get the end of the stick when the discussion turns to environmental issues - wasting fossil fuel, generating exhaust pollution, killing fauna, and all for just selfish personal entertainment. It's too much of a disastrous carbon footprint to justify the ego trip of motoring over natural terrain for no good reason, some people scream.
Well, guilty as charged, I suppose. I love the rumble of a petrol V8 engine, especially up a quiet mountain trail. I don't mind a smoke-belching diesel, either, especially through deep mud and water passages. And I absolutely reach motoring heaven on my two-stroke, 350cc quad bike on the sand dunes.
There is no doubt compromises need to be made and, indeed, will be forced upon us eventually. Hopefully we will soon be offered zero-emission, solar-powered 4x4 vehicles with comparable torque, and we can play the sound of rally car engines on our audio systems if we miss the sound stimulation of a roaring combustion engine.
In the meantime, here are some things we can do to minimise our effect on the environment.
Petrol consumption is normally quite dramatic off-road, but staying out of the low gearset is a useful step: the engine will rev less in the high gears and the gears will range longer, requiring less frequent shifts. Engage low only when really needed, such as when escaping from a stuck situation, or on a steep descent, then shift back into high gear right away.
On soft sand, tyres are deflated to increase footprint, and when the drive ends back on tarmac a decision is taken whether to inflate with a portable compressor (slow, and has you standing in the sun) or to just drive slowly to a nearby petrol station. If you carry an air compressor, better use it, to save both gas and wear on the tyres; driving with deflated tyres on tarmac is also dangerous. Heavy acceleration, and subsequent braking, make a big difference to the economy you'll get out of your vehicle; on remote expeditions, where the amount of fuel is limited, one of the golden rules is to maintain a steady speed.
If you're out to play on the dunes, you'll likely not want to be too gentle with your right foot, but saving it for when it's required by the terrain is a fair compromise: avoid spinning wheels unnecessarily when on the flat.
Littering, I believe, we can do away with immediately, as there can be no valid reason for dumping rubbish in natural surroundings.
Most desert animals stay far away from loud vehicles and hide in the bushes and underground, so there is little chance of killing them. But plants definitely can be damaged, even killed, by heavy-duty off-road wheels, so staying off the green stuff as much as possible is a fair rule. If you've ever driven on the sand dunes after rain, you'll know that wherever tyres pass, the fresh green grasses don't survive.
Are our off-road trips defensible in a world of dwindling resources and delicate ecological survival? I'll let you decide that one, but they can definitely be made easier on our environment without losing all the fun.