Carbon footprints are widely talked about when discussions of sustainability, emissions and climate change come up. The general idea seems to be that the atmosphere (or at least the proportion of the atmosphere that relates to carbon dioxide) is sort of like a clean kitchen floor that you can leave footprints on. The idea is to keep the kitchen floor clean, so to speak, by tiptoeing over it in soft ballet slippers or barefoot, rather than tapdancing all over it in filthy rugby boots that are all spikes and mud. What your footprint is like is determined by how many emissions you, personally, generate by your lifestyle choices. Online carbon footprint calculators are handy ways of finding what sort of atmospheric shoes you're wearing. These calculators also tell you various ways that you can "offset" your carbon footprint. In kitchen floor terms, this is the equivalent of a mop, broom, scrubbing brush or floor polisher. You may live a lifestyle that is the equivalent of tramping around in Wellington boots, but if you know how to clean up after yourself, the overall effect will be the same as if you were going barefoot - or at least wearing clean sneakers.
Online carbon calculators consider a number of factors. These range from how many people live in your home, what sort of home you have, how you heat your home, what work you do, how you travel from A to B and how often, whether you fly overseas, food choices, recreation choices, and even how much of a shopaholic you are.
You also learn ways that you can scrub your footprints off the floor. These include insulating your home (so you use less energy), using sustainable zero-carbon means of generating power or heating your home (e.g. solar panels, solar water heaters, wind turbines), recycling and becoming involved in schemes to plant trees (trees absorb carbon and clean up your emissions - they even look like mops).
Let's consider Dracula as an example of how a carbon footprint can be worked out. On the negative side, Dracula lives alone in a very big castle, which is poorly insulated. He eats hardly any vegetables - if any - and meat creates more carbon emissions to produce than vegetables. He also habitually dresses in very fashionable clothes to maintain his aristocratic image. On the positive side, Dracula chooses to heat his home with a roaring log fire (in spite of the smoke, wood fires are fairly carbon neutral - you need to grow trees to get the firewood, and not all the carbon that the trees absorbed is released into the atmosphere when the wood is burned - ash, charcoal and soot are usually left behind and get added into the soil, and some carbon will also be absorbed by the leaves that the tree once grew before it became firewood). And Dracula also uses a zero-emissions form of transport (flight in the form of a bit - the normal human equivalent is walking or biking) and doesn't take long overseas trips by aeroplane - it could be a bit tricky getting that coffin containing his native soil into the plane so he can sleep in it, even flying first class.
Dracula could offset the carbon emissions of his food and fashion choices by planting a large forest around his castle, and could consider upgrading his heating and lighting system by installing solar panels and a solar water heater - if this doesn't make him disintegrate - and could try getting some insulation put in all those attics and towers. He could also get more people in to live at that castle.