Impact of city changes and weather on anthropogenic heat flux in Europe 1995-2015

How people live, work, move from place to place, consume and the technologies they use all affect heat emissions in a city which influences urban weather and climate. Here we document changes to a global anthropogenic heat flux (Q_F) model to enhance its spatial (30''×30'' to 0.5°×0.5°) resolution and temporal coverage (historical, current and future). Q_F is estimated across Europe (1995-2015), considering changes in temperature, population and energy use. While on average Q_F is small (of the order 1.9-4.6Wm^-2 across all the urban areas of Europe), significant spatial variability is documented (maximum 185Wm^-2). Changes in energy consumption due to changes in climate are predicted to cause a 13% (11%) increase in Q_F on summer (winter) weekdays. The largest impact results from changes in temperature conditions which influences building energy use; for winter, with the coldest February on record, the mean flux for urban areas of Europe is 4.56Wm^-2 and for summer (warmest July on record) is 2.23Wm^-2. Detailed results from London highlight the spatial resolution used to model the Q_F is critical and must be appropriate for the application at hand, whether scientific understanding or decision making.