2009

1 pollutant + N cycle

2 electricity and energy

3 dams and ecosystem

4 agriculture and GM crops

2010

1 Pollutants

2 Termite and the Environment

3 Invasive species

4 Rise in sea level

2011

1 ecosystem

2 coral reefs and envrionment

3 energy

4 population and agriculture

2012

1 natural gas

2 CO2 emission

3 pesticides and experiment

4 wetland

2013

1 fertilizer and environment

2 energy and electric vehicle

3 O3 and air pollution

4 biodiversity

2014

1 nuclear power

2 wastewater treatment

3 Plate-tectonic theory

4 matter cycle

2015

1 water pollution

2 e-waste

3 oil spills

4 urban sprawl & smart growth

2016

1 disease and bats population

2 iron ore

3 solid waste

4 soil formation

2017

1 wasterwater treatment

2 mammal extinction

3 deforestation and demographics

4 dams

2018 

1 green roof

2 wind farm

3 food web

4 air pollution

2019

1 general ecosystem

2 deforestation and oil sands

3 CO2 and pH

4 air pollutants

2020

2021

2022

NULL