It seems to me that carbon footprint is a rather narrow measure of the impact of our actions on the environment. Pursuing minimisation of carbon footprint as a primary goal could lead to an unhelpful form of asceticism, where even good actions are forbidden, if they increase carbon footprint. Any action, whether helpful or harmful, has a cost in terms of resource consumption. However, good actions may result in a "profit", that outweighs the cost. Inaction, though it has minimal cost, cannot provide a benefit.

Though I have used terms from financial accounting and economics, I do not think the costs and benefits of our actions can be reduced to monetary values. For example, I think Gross National Product is often a poor measure of the well-being of a nation. It can be just an indication of corpulence and waste.

As an engineer, I am inclined to convert most costs to energy input, regardless of whether this energy comes from renewable sources. Expending more energy generally means having bigger impacts on the environment, and with great energy expenditure comes great responsibility. Even if we were to find a way of making electricity without a significant environmental impact, the use of this magic resource would inevitably have an impact.

Some of this energy-equivalent accounting can be awkward. The manufacture of electric vehicles consumes mineral resources such as Cobalt for their batteries. We need some way to set this cost against the costs of burning fuel in internal combustion engines, before we say that EVs are so much better than ICEs. An interesting point here the true cost of mining Cobalt ore. Currently, a significant amount of this mining is ultimately done by poor people, including children, using their bare hands and only the crudest tools. This does not cost as much as mechanised mining in terms of direct energy inputs such as fuel, but must surely have a cost in other terms.