Local GHG emissions vary tremendously from place to place, depending on each area’s biophysical, socioeconomic, and cultural contexts. For example, a college town in central Pennsylvania (hey, I know one of those!) will have a significantly different emissions profile than an agricultural area in southwestern Kansas or an industrial city in northwestern Ohio. Indeed, each place’s GHG emissions profile is unique, but a few important sources appear in most locales. Those sources are energy use, transportation, waste disposal, and land use.
Local energy use is complex and varies with the specific type of user: residential, industrial, or commercial.
Residential:& This graph below shows how we're using energy in our homes here in the United States. More than half of it is to heat and cool our spaces (which means this also represents our biggest opportunities to reduce energy demand through gains in efficiency or moderated used). Understanding our energy consumption at home empowers us to make decisions that lower our utility bills and reduce our demand.
Residential GHG emissions are extremely important in both their quantities and their symbolism. Symbolically, residential emissions are vital because almost every person has a primary residence and has (some) control over his or her energy use and resulting GHG emissions. Large opportunities exist in reducing household energy consumption. Local emissions obviously vary with climate, socioeconomic status, energy systems, and more.
- Think about the things you can do in your home to reduce energy use. (I'll go first - I have made three big changes that I see on my now-lower bills: (1) I don't let my dishwasher dry my dishes, (2) I use a lower heat setting on my dryer, and (3) I set the thermostat higher in the summer and colder in the winter by a few degrees each way. Doing those things, I reduced my monthly energy bill by about 25%!
Our energy use at home is determined by a variety of factors. EIA points them out on their Energy Use In Homes page:
- Location - hey look, geography matters! (spoiler alert - geography always matters!) Your climate will dictate your heating and cooling needs, and we already determined those are the biggest piece of our energy use pie.
- Type of housing - Maybe your apartment is snuggled in among others and stays pretty cozy in the winter without needing to crank the heat too much. Or, maybe you rent a house like I did in grad school where I could see my blinds and curtains move when the wind blew because it was so drafty.
- Devices - we're adding devices to our daily lives all the time. I look around my own home at the things we're plugging in - phones, Switches, tablets, a dehumidifier that runs constantly in the basement, our pandemic era acquired chest freezer. These all require energy.
- Size of household - this is an interesting one because there are some efficiency gains to be made by more people living in one spot than occupying separate individual spaces that need to be heated/cooled separately, but that is then offset by the increased demand on laundry, hot water for showers, running the dishwasher more frequently, etc. And, there's the behavioral component. When my husband is away, I adjust the thermostat to a much more energy-saving temperature.
Do you know what kind of energy sources are used to power your home? Check out this visualization from Carbon Brief illustrating electricity sources across the US.
Industrial uses of energy reflect their GHG emissions. Utilities emit the most GHGs; manufacturing emits the next greatest proportion; mining and related extractive industries emit a smaller yet still significant proportion; and all other industrial activities emit a small quantity of GHGs. Manufacturing involves hundreds of products and processes including such diverse activities as dog food manufacturing, yarn spinning, house slipper manufacturing, ethyl alcohol manufacturing, and lime manufacturing. Local manufacturing can be specific and unique, meaning that local GHG emissions from manufacturing can also be specific and unique. For instance, because Seattle is home of Boeing’s main production facilities, emissions from aircraft manufacturing is unusually dominant in that city.Millions of commercial enterprises consume energy daily. Keeping the commercial space comfortable for employees and customers through lighting, space heating, and ventilation consumes much of the energy, though these percentages are fluctuating as energy efficiency in various areas improves. For example, a decade ago, lighting was 25% of the total. Commercial food preparation also uses a large amount of energy. While local commercial energy use and GHG emissions are unique, but there is a remarkable uniformity in commercial enterprises across modern society. For local scale inventorying work, commercial energy consumption typically generates a 'low-hanging fruit' opportunity to reduce emissions and save building owners/occupants money by doing so. The data in the table below represent the most recent finlized data published by EIA. A more recent Commercial Energy Survey was conducted in 2018 (see Preliminary Results), but the space heating demand shown below has not yet been released (c'mon, EIA!).
Institutions, which include such diverse entities as government buildings, prisons, military facilities, and schools, colleges, and universities, are important consumers of energy and emitters of GHGs (and are considered commercial buildings). Each local institution has a unique energy use pattern and GHG emissions profile, but, until recently, construction of most institutional buildings focused on building costs and not on energy efficiency. The net result is that the institutional sector tends to waste energy; large opportunities for energy savings and GHG reductions exist.
Local land use varies dramatically over space and time. Different places use their land for agriculture, commerce, industry, transportation, mining, forestry, or conservation. Some places have mixed land use, whereas other places have only one or two primary land uses. Each land use is associated with a particular GHG emissions pattern. Cropland emits relatively large amounts of nitrous oxide from the surface, while pastureland emits relatively large amounts of methane from cattle and other ruminants; feedlots emit much greater concentrations of methane than pastures. Forests tend to be sinks for carbon dioxide, but clear-cutting releases significant amounts of this GHG. Urbanized and suburbanized areas are hotbeds for GHG emissions: they emit large quantities of GHGs through residential, commercial, institutional, and possibly industrial activities; urban transportation activities similarly emit huge amounts of GHGs; even suburban fertilized lawns emit nitrous oxide. Thus, localities must account for their land-use emissions when addressing climate change.