'Participants who engaged more in energy-conserving behaviors had less accurate perceptions of energy use and savings... '

'Participants who engaged more in energy-conserving behaviors had less accurate perceptions of energy use and savings, possibly reflecting unrealistic optimism about the effectiveness of their personal energy-saving strategies compared with alternative ones ...'

The conculsion of the report 'Public Perceptions of Energy Consumption and Savings' issued by the Earth Institute at Columbia University. It seems that the sort of people who make an effort to be eco-friendly - for instance by recycling glass bottles, turning off lights and unplugging cellphone chargers - have no idea how effective what they are doing really is.

You can read the whole report in pdf format here and a pretty good summary of environmentalist lack of knowledge in The Register, here's an extract:

'...one highly popular activity among green-conscious folk both in the States and the UK is the recycling of glass bottles. The respondents in the survey actually considered that glass bottles require less energy to make than an aluminium can, which is totally wrong. Glass requires so much energy to make - or recycle - that it is always more eco-friendly to use aluminium cans, even if one is talking about virgin cans compared to recycled bottles.

As a true eco-person, you shouldn't be recycling glass: you ought not to be using it at all.

Again, when asked what the single most effective thing they could do to save energy, the most popular response in the survey was to turn off lights. In fact lighting accounts for a relatively small proportion of the average person's energy use and almost all of us could save far more juice (and carbon) in other ways - for instance by turning the heating down as little as a single degree, something which many extremely keen lightswitch nazis refuse to do.

Another behaviour which people commonly consider to be energy-virtuous is the unplugging (or switching off at the wall) of appliances on standby or unused cell-phone chargers. This is an even bigger waste of time than switching off lights: a modern TV on standby uses less than a watt of power. You would need to unplug it or switch it off for a year to save as much energy as it takes to have one-and-a-half baths.'

These people aren't about saving energy or reducing CO2 emissions, they want to seem more 'right on' and 'good' than you so they can take the moral high ground. The fact that they are ignorant fools just will not be accepted.