Energy use, greenhouse gas emissions and global warming.

This chapter focuses on another main pathway through which global environmental change has impacted human and environmental health: our use of energy, particularly when produced from non-renewable, carbon-based fuel sources. It presents historical data showing the increasing rates of energy use over the years, and discusses the effects of urbanization and population growth on energy use. Energy use is the key driver of climate change. The energy sector alone is responsible for two-thirds of all global carbon dioxide emissions, and thus its use leads to increased land, water and air temperatures, heat stress, more severe weather events and ocean acidification. Depending on the energy source, its use can also release toxic materials into the environment. The impacts on human health are not always straightforward, however. Energy has many benefits: it generates electricity to power heating, stoves and refrigerators, homes and hospitals, factories and schools. It provides heat and light, fuel for transport and power for manufacturing.