This lesson is devoted to understanding the emissions that drive climate change. We've broken them down by sector to try to understand how our actions result in a changing climate (we'll need to know this if we have any hope of doing something to solve it!). As you consider these emissions sectors, also think about the proximate causes and driving forces contributing to the emissions patterns. What do you see?
- Energy demand and consumption are growing rapidly, especially in many of the most heavily populated and underdeveloped areas of the globe. You saw that so-called clean coal technologies still produce huge quantities of GHGs and that natural gas generates significantly fewer GHGs, but that only non-fossil fuel technologies emit negligible amounts of GHGs. The energy sector contributes to climate change through power production and industrial processes. Because this sector contributes more GHGs to the atmosphere than any other, it's important for us to understand it thoroughly (as we'll see later this semester - it'll represent some of our biggest opportunities for turning this around).
- Transportation is a major and growing contributor to global GHG emissions. Road transport is the fastest-growing portion of this sector because rapidly increasing numbers of the world's population are becoming sufficiently affluent to afford cars and light trucks. Although it seems to have saturated its market potential, the United States is still the biggest contributor to global emissions from transportation, which is really no surprise when we consider the cultural values promoting the freedom of individual car ownership, the layout of our cities, and the relatively limited availability of affordable, reliable public transportation options.
- Agriculture is energy- and land-intensive, and this varies of course based on the type of crop or livestock being produced. There are direct emissions associated with livestock and crop production (ventilation in the barns, fuel for tractors, etc.) and there are indirect emissions (energy to produce animal feed or crop fertilizers).
- Various types of land use sequester carbon (some more efficiently than others), so this is a consideration for us as we think about land use change on a global scale. What type of land sequesters carbon the most? Forests! Agricultural soils also sequester carbon.
- Waste - even when we've discarded something, its emissions story is not over. Landfills produce a significant amount of greenhouse gas emissions (mostly methane) from the decomposition of organic matter like our food waste and yard waste.
Reminder - Complete all of the Lesson 2 tasks!
Refer to the Lesson 2 overview page and to Canvas to ensure you've completed all assigned work.