Easy & cheap
Replace old light bulbs with LED lighting
Increase loft insulation
Install Cavity wall insulation
Improve draught proofing
Screw on a low flow shower head
Place reflectors behind radiators on external walls
Switch to a Good Energy supplier
Medium – some investment, reasonable payback time
Upgrade single glazing to double or triple
Install Solar PV
Replace an old gas boiler with a condensing one
Committed – higher level of investment & disruption
Install Solid Wall Insulation
Get a renewable heating system such as a biomass boiler or a heat pump.
Install Solar Thermal
Measure Your Carbon Footprint
The size of your Carbon Footprint is the amount of greenhouse gas emissions for which you’re responsible, and depends on your lifestyle, how much you fly, and so on. You can use an online tool to calculate it, and the best one I found was:
The size of carbon footprint for each person on the planet that is sustainable is uncertain, but may be around 1.5 tonnes.
The UK average is over 13 tonnes.