Household CO2 emissions are a significant contributor to global greenhouse gas emissions and consequently climate warming. Despite this, there has been little consideration of how household CO2 emissions may be affected by changes in climate. The aim of the present study has been to investigate the way climate, as well as socio-demographic characteristics, may affect household CO2 emissions produced from energy use. A national online survey was conducted to determine current household CO2 emissions in Australia as well as capture the ownership and use of household appliances and installations. Electricity and gas-based emissions as well as the ownership of a variety of household appliances and installations were found to be strongly associated with temperature. Electricity and gas emissions were found to decrease as annual average temperatures increase. However, as temperatures continue to rise under climate change this pattern may be reversed owing to increased reliance on air conditioners. One option for preventing this from occurring is to encourage houses to adopt more solar-passive installations. Although this may be expensive, households with higher emissions tend to have higher incomes, indicating that they may have the capacity to pay for such installations.