Earth (planet) 25 Orbits 18 Satellites 18 Climate change 15 Stars 12 Planets 11 climate change 10 Exo-planets 9 Sustainability 9 Planets and satellites: atmospheres 8 planets and satellites: atmospheres 7 Climate models 6 Protoplanetary disks 6 machine learning 6 Conservation of the environment 5 Ecology 5 Ecosystems 5 Environmental policy & protocols 5 Extrasolar planets 5 'current 4 Applied ecology 4 COVID-19 4 China 4 Development economics & emerging economies 4 Earth sciences 4 Earth system models 4 Machine learning 4 Media studies 4 Planet-star interactions 4 Planets and satellites: compositions 4