Carbon-intensive energy, such as coal, is required to meet nighttime demand for electricity in winter, while cleaner energy, such as solar, is more common during the day and in the summer months. Therefore, watching television on a cold winter night is worse for the environment than doing so on a sunny afternoon. On a technical level, installing LED lighting can in fact be more effective in reducing carbon emissions than installing solar power, depending on the timing of one’s consumption.

A report published by sustainability consultants at WSP focuses on the variability of carbon emissions, warning that substantial inaccuracies in current measurements may lead to poor decision making for new developments and investments. The report, titled An investigation into the use of temporal factors for CO2 emissions accounting in buildings, stresses that inaccurate results produced by the current system for measuring carbon emissions from buildings and businesses can have a significant impact on both the environment and corporate balance sheets.