There is a reason for the disparity between charitable giving among people who advocate smaller government and larger government; people who advocate larger government already feel like they are doing their part by paying more in taxes, so they give less to charity.

That same mindset limits green consumerism, says economist Dr. Grischa Perino from the University of East Anglia (UEA).  Schemes that aim to regulate greenhouse gas emissions make people feel like they have already done their part by paying more money in government programs and are less motivated to care on a personal level - in a cap and trade scheme, the emissions are already paid for so people might as well fly on a plane.  His findings are based on a mathematical model of consumption choices so use results sparingly, as you would any claim by an economist.

Perino thinks the recommendations made by government agencies and environmental NGOs to reduce greenhouse gas emissions are inappropriate in the European Union because of its Emissions Trading System (EU ETS) - people are already told how often to fly, unless they are elites, that they should not eat meat and that they should buy more expensive light bulbs. But with a new cap and trade scheme, all those ideas are invalidated, argues Perino, because those recommended actions suddenly have no impact on total emissions,  they are simply paid for already in the system's trading mechanism. He claims that out of the above examples only eating less meat reduces total emissions, because in contrast to electricity production and aviation, emissions from agriculture are not covered by the EU cap and trade. But even the metrics for the detrimental impact of eating meat are mostly made up. 

"Buying energy efficient appliances still makes a lot of sense as they often save more on electricity bills than the extra cost incurred in buying them and it reduces other forms of environmental pollution, but it does not reduce greenhouse gas emissions," said Perino, but when it comes to getting people to contribute to reducing their carbon footprint, otherwise cap and trade efforts can "backfire". "Consumers who want to reduce the climate impact of their consumption and lifestyle should focus on reducing emissions not regulated by the EU ETS, such as road transport, agriculture and other sectors with low energy intensity. Driving your car less, eating less red meat and improving the insulation of your home substantially reduces your carbon footprint. These unregulated sectors make up more than half of GHG emissions in participating countries and reducing those emissions is important."

The EU ETS is the biggest international system for trading GHG emission allowances and a cornerstone of the EU's policy to combat climate change. Under this so-called cap and trade scheme, emissions by one regulated source can be offset by another and firms that hold more emission allowances than they need can sell these to other firms, which in turn use them to increase their own emissions.

Perino recommends that to reduce emissions in EU ETS sectors such as electricity production, people should put pressure on politicians to reduce the cap of the EU ETS even more. They can also buy and 'retire' emission allowances, thereby having a direct impact on emissions. He suggests that carbon footprint labels measuring the life-cycle emissions of a product do not give consumers helpful guidance on how to reduce actual emissions, because they do not differentiate between emissions covered by the EU ETS and those that are not.

Sometimes taking the train is worse for the environment

"My analysis shows that basing decisions to reduce carbon footprints on both regulated and unregulated emissions, as recommended by government agencies, NGOs and established carbon footprint labels, can increase total emissions," said Perino. "For example, if you consider making a trip from London to Glasgow, flying has higher physical GHG emissions than a coach journey. However, additional emissions of flights are fully offset by the EU ETS, even without buying the offsets offered by most airlines when buying tickets, while those of the coach are not and therefore are additional. Surprising as it may sound, going by coach increases total emissions more than flying."