Not all four wheel drives are gas guzzling trucks, though some important points should be noted:

• Contrary to the antics of some celebrities, you can not help the planet by buying a new car. If a car hasn't reached the end of its life, replacing it just adds another car to the world.
• Diesel engines are slightly more efficient than petrol engines, but result in a massive increase in toxic and smog-forming emissions. (See the environment page)
  
• Modifying a petrol guzzling SUV to use natural gas or LPG will do more to reduce life cycle environmental costs than buying a fancy new hybrid.
• For any vehicle increased height reduces overall safety, for on-road driving.
• Adding 4WD always increases weight, fuel consumption and emissions compared to 2WD.
• One could always hire a 4WD for trips using the money saved by owning a more economical car, micro-car, bicycle, light electric vehicle, car sharing, using public transport, walking...
• Owning the biggest meanest SUV, but riding a bicycle for day to day transport needs will do less environmental dammage than commuting to work in the latest hybrid greenwash-mobile.

Smaller SUVs
These still have relatively high centres of gravity, and many have especially high occupant death rates from rollovers [1]. However at least their smaller size and mass make them more fuel efficient than large sedans and less aggressive to other road users than larger SUVs.

Fuel consumption figures using the combined city/highway UN ECE R 83 standard. Visit the VCA database from the UK, or the Australian 'Green' vehicle guide for more figures.

Cars, wagons and minivans that also come in 4WD
There are cars that come in four wheel drive but without the safety problem of increased height.

Others include the Mitsubishi Magna, Jaguar X type, Mercedes E Class, Toyota Corolla, Mazda 626, and Honda Civic, but they aren't all sold new in NZ or Australia.

Front wheel drive vehicles 
If you don't regularly drive up slippery dirt roads, or boat ramps you can destroy the planet slower with front wheel drive only.

[1] Consumers Union (USA)