Traffic and the road to nowhere.
Apparently last year vehicles travelled 327.1 BILLION miles on British roads. Now try converting that to CO2, Sulphur dioxide, other gasses and contaminants that pass into the air, soil and water ways! And of course this is only one of many such sources, which is repeated all over the globe.
Because we view vehicles individually, we fail to appreciate it in its entirety. Despite an obvious need to reduce this source of pollution, for every area, apart from urban ones, traffic continues to rise (4.2% in last decade).
As travel is made easier and faster, so journeys are extended. As traffic increases, so does the demand for more and faster roads. Where once few families afforded a car, now most appear to have several. Where a century ago most were content to remain in their parish, and were no more socially deprived by it, now people range far and wide, but are rootless and disconnected.
The effects on nature are there for all to see. With other agricultural changes, in the past fifty years we have decimated flora and fauna, yet we are open mouthed as to how and why this should have happened.
One thing is sure: humans have created this situation and only humans can reverse it. It starts with every driver questioning whether their journey is necessary, whether other alternatives such as walking, cycling or public transport are not better environmental alternatives and by driving less aggressively. That is just for starters.