Cooling and heating degree-day methods primarily address sensible HVAC loads including infiltration and exfiltration. Although it has been recently shown that daily temperature variations of the dry-bulb and wet-bulb air temperatures are similar, this finding alone may not substantiate the omission of latent loads in today’s degree-day methods. Solar gains in cooling loads are also important. In addition, it is becoming more important to know the second-law efficiency (Exergy) of buildings in order to calculate the carbon footprint of especially high performance and green buildings. Carbon footprint calculations require both sensible (including solar gains) and latent loads. In this study, the latent loads and solar gains in comfort cooling have been incorporated into a new exergy cooling degree-day method. This method is directly applicable to calculate the total carbon emissions of a building using the Rational Exergy Management Model (REMM).