A carbon footprint is a measure of the tonnes of CO2 you have produced over a certain period. This takes into account anything including household costs, transportation and leisure activities. It's important as individuals we do our best to understand our impact we have on the environment and do our best to reduce it, because our leaders simply wont.
Carbon dioxide is naturally produced in many ways and isn't itself bad for the environment, what is bad is the unnaturally huge amount we produce in modern society. By now, everyone has heard (even the climate deniers) that this causes the 'Green House Effect', where the thick layer of CO2 around our planets thin atmosphere is trapping heat and causing climate change.
Much of this CO2 is produced by the burning of fossil fuels including gas and oil, and one of the main reasons why little climate action has been taken by our governments is because those that own the fossil fuel companies have too much influence and power and to accept climate change as this would leave them out of pocket.
Being off grid, a van lifer quickly learns the value of resources, whether it be fresh water, diesel, electricity etc where it would be normal to have in abundance. So whether they care about the environment or not, they generally use less of everything, this means their carbon footprint is less than a normal household in many ways.
But then theres the fuel. We realised after calculating our own footprint that (even though we've only done around 10,000 miles in a year on 35mpg) it contributes to 75% of our footprint, and I've seen van lifers with less efficient vehicles do over 50,000 miles in a year!
Unfortunately there are few alternatives to diesel out there at the moment. Many of the main van manufacturers have only just announced electric vans, all small wheel base, short ranges, and very expensive.
So, while van lifers are often ecological, the problem of diesel is important to offset as there is no realistic alternative right now, and being an earth loving community it's in our hearts to do so.