I have enhanced the placemark file to show a visual representation of the emissions from each site by extending a coloured polygon above the site.



The width of the polygon is proportional to the number of substances emitted (reported) by each site. This is the "footprint". The height of the polygon is proportional to the size of the emissions. Red is for air emissions, blue for water and yellow for land.

Since it would be meaningless to add up the kg emitted of each substance (the big emissions would drown out the smaller ones) I have linearised the data assuming a lognormal distribution. I did this by calculating the Z-score of each substance emitted relative to national emissions. I then added the Z-scores for all the emissions of each site and divided by the square root of the number of emissions.