If we are looking after sheep, it’s easier to keep them in a field with the gate shut than to let them escape and try to round them up later. In a similar way, it is simpler, cheaper and more effective to control CO2 emissions ‘upstream’ — at the relative handful of places where coal, oil and gas come out of the ground — than trying to control emissions ‘downstream’ at the much larger number of emissions-producing businesses or individual people. Likewise for other industrial greenhouse gases.

The EU Emissions Trading System is not effective in cutting emissions and cannot be fixed in its present 'downstream' form.

Upstream reform of the EU ETS would be relatively simple to do and would enable the system to work effectively.

See "Turn off greenhouse gases at source", www.mng.org.uk/turnofftap .