0809_Natural_Ecosystem_Change

1.1   0800_Environmental_Science

1.2   0801_Environmental_Systems

1.3   0802_Geology

1.4   0803_The_Atmosphere

1.5   0804_Water_Resources

1.6   0805_Soil_and_Soil_Dynamics

1.7   0806_Ecosystem_Ecology

1.8   0807_Energy_Flow_in_Ecosystems

1.9   0808_Ecosystem_Diversity

1.11   0810_Biogeochemical_Cycles

1.12   0811_Population_Ecology

1.13   0812_Human_Population_Dynamics

1.14   0813_Human_Population_Size

1.15   0814_Human_Population_Impacts

1.16   0815_Agriculture

1.17   0816_Forestry_and_Rangelands

1.18   0817_Land_Use

1.19   0818_Mining

1.20   0819_Fishing

1.21   0820_Environmental_Economics

1.22   0821_Energy_Concepts

1.23   0822_Energy_Consumption

1.24   0823_Fossil_Fuels

1.25   0824_Nuclear_Energy

1.26   0825_Hydroelectric_Power

1.27   0826_Energy_Reduction

1.28   0827_Renewable_Energy

1.29   0828_Air_Pollution

1.30   0829_Water_Pollution

1.31   0830_Solid_Waste

1.32   0831_Health_Impacts_of_Pollution

1.33   0832_Stratospheric_Ozone

1.34   0833_Global_Climate_Change

1.35   0834_Loss_of_Biodiversity