Direct estimation of diffuse gaseous emissions from coal fires: Current methods and future directions

► Dynamic closed flux chambers impacted by water vapor buildup and windy conditions ► Dynamic open chambers sensitive to flux chamber flow and turnover rates ► Co-simulation of soil temperature and gas flux ideal for CO2 flux interpolation ► Diffuse emission from Ruth Mullins case study roughly 0.07-0.09 t CO2 d− 1 ► Paucity of direct time series emission data is largest current data gap