The phrase "to reduce that footprint" refers to taking actions or making changes that will lead to a smaller impact or harm on the environment or a particular situation. Full definition
This would further reduce the footprint of making hybrids and electric vehicles. (treehugger.com)
This actually has more to do with the S8 +'s incredibly narrow borders around its screen, which reduces its footprint in your hand. (businessinsider.my)
We are firm believers in reducing our footprint as much as we can. (nunaturals.com)