Why Energy Efficiency Doesn't Always Mean Reduced GHG Emissions

According to Ecometrica energy efficiency doesn't necessarily result in reduced GHG emissions.

While improvements in energy efficiency often represent progress in reducing GHG emissions, the relationship may not be 1:1 and should not be assumed to occur automatically, either at the level of a business or in the economy as a whole.
There are a number of ways in which potential emission reductions from efficiency improvements can be “eaten up” in other parts of a business or economy, through “comfort taking”, and financial transfers to other carbon intensive activities. It is therefore important to capture the overall effect of changes in energy usage within a broader GHG accounting framework, such as the WBCSD-WRI Greenhouse Gas Protocol (for businesses) or national GHG reporting systems.