Y'all know the carbon footprint, describing the CO2 emissions released into the atmosphere by a company etc.. I am pretty unsure, if it needs to be to "improve" or to "reduce" the carbon footprint. Can anyone help me?
Footprint(s) has been used figuratively as ‘mark’ or ‘impact’ since the early 17th c. and continues in present day English:
…that of alexander is more renowned, and first opened the east to the west, and to europe gaue the eyes of geography and history, to take view of india and the regions adiacent: and here is the first solid foot-print of history in this kind, though heere also Trauellers haue beene as farre from the truth, as from their homes, and haue too often trauelled of Vanitie and lies … — Samuel Purchas, Purchas his pilgrimes, 1625. EEBO
The size of the impact of China’s activity on the prices of specific commodities varies with China's footprint in that market. — Christina Kolerus et al., China's Footprint in Global Commodity Markets, 2016, 1.
So, for instance, when the Chinese developed a taste for pecans, prices shot up and the American domestic market was squeezed, i.e., the Chinese economic footprint increased all across the American South. Footprint as spatial metaphor can only increase or decrease in size, just as an impact can be lesser or greater, but neither improved.
If, however, one completely disregards the metaphor and thinks of carbon footprint as a numerical score, measured, say, in CO2 tonnage, then it’s analogous to any competitive sport where the lowest score wins. No one says they want to reduce their golf score or racing time; they want to improve it.
In this sense, whether you reduce your carbon footprint or improve it depends on how dead the footprint metaphor is in the mind of the speaker. Both are legitimate means of expressing the same thing.