Carbon dioxide Sustainable development 6 CO2 emission 5 CO2 concentration 4 Global warming 4 Temperature 4 carbon dioxide 4 % reductions 3 Atmospheric temperature 3 Biodiesel 3 CO 2 concentration 3 CO 2 emission 3 Carbon 3 China 3 Climate change 3 Environmental management 3 Forecasting 3 Neural network predictions 3 Neural-networks 3 Particle size 3 Post weaning cycle 3 R value 3 Reusability 3 Scanning electron microscopy 3 Set-point temperatures 3 Supercritical fluid extraction 3 Temperature programmed desorption 3 Ventilation 3 Ventilation flow 3 Weaned piglet 3