Settle down a little. The Greenies aren't 'protecting' the outdoors any less then the NRA is 'protecting' gun rights. Besides, this is just some scientist announcing what he has found. It's like a press release and just as believable.
The WWII Tank comment is to show an example that some area's simply don't rebound.
This is not all area's, just some. Sort of like how your not supposed to step off the trail in Moab. It takes over 50 years for plant life to be able to try and grab a spot, and a second with a careless foot to destroy it.
It's a discovery, not a proof of theory. He is using sport 4x4 use as an example because it is something everyone can relate to. It's a bad example, but an example none the less.
Mongolia is slowly turning into a desert because of overharvesting of plants, there are lots of things that can contribute to the increase of dust. Like it or not 4x4's may be part of it. All the more important that we stay on established/marked trails.
The dust clouds increase as the amount of desert increases. The amount of desert increases due to the destruction of plants that keep the desert in check. The destruction of the plants happen because of irragation moving the water elsewhere, change of habitat causing animals to move to new areas to find food, people selling the plants as a natural alternative to viagra, vehicles driving around on it, farmers turning it into a field.
And to be fair, we did do permanent damage to the moon. We just don't care. But when the Country Club moves into the Sea of Tranquility you bet there will be 'ell to pay for those driving through the groomed view.

These are just my opinions though and could be way off.