1. What is meant by waste? In this Calculator, waste means household garbage. This includes everything you put at the curbside for pickup (either in garbage containers or in recycling containers), plus the amount that you compost. Add it up in terms of the number of standard-sized plastic garbage bags it would take to hold all the waste your household produces in a typical week. The Calculator assumes every bag holds 10 kilograms (22 pounds) of waste.

2. How do I know how many bags of waste I produce? Household waste is disposed of in many different containers, including bags and garbage cans of various sizes and different types of recycling containers and composting bins and piles. To keep things simple, estimate the number of standard sized plastic garbage bags it would take to hold all the waste your household puts at the curbside in a typical week (including recyclables), plus any amount that you compost. In this Calculator, a bag of waste is equal to 10 kilograms, or about 22 pounds. As a rule of thumb, the average westerner produces about 7 kilograms of residential waste a week, so a household of four people would typically produce about 30 kilograms or three bags per week and a two person household would typically produce 1.5 bags per week.

3. How does recycling affect my personal emissions? Recycling reduces your personal emissions. When you put waste in the recycling bin instead of in the garbage, instead of being sent to the landfill, it gets re-used by industry to make new products (paper, glass, plastic, aluminum, etc.). This reduces greenhouse gas emissions in three ways. First, when organic material (this includes all paper products) decomposes in landfill sites, it produces methane, a powerful greenhouse gas. By recycling organic material, landfill methane emissions are eliminated. Second, and even more important, recycling allows industry to save large amounts of energy (and therefore greenhouse gas emissions). When paper, glass, steel, plastic or aluminum are produced from raw materials (trees, crude oil, iron ore, etc.), the process takes more energy than when these products are produced from recycled materials. And finally, when you recycle any wood or paper product, less trees have to be cut down and this reduces carbon dioxide emissions even further.

4. How does composting affect my personal emissions? Composting reduces your personal emissions. When organic material is composted, it breaks down in a way that produces little or no emissions of methane (a powerful greenhouse gas emitted by landfills). This means that increasing the amount of waste you compost instead of sending it to the landfill will reduce your personal emissions. Composting, which has many other environmental benefits, is a "climate friendly" thing to do!

5. How does my garbage affect my personal emissions? The more garbage you produce, the more your personal emissions of greenhouse gases will go up. The amount of garbage you produce affects your greenhouse gas emissions in a number of different ways. At the most basic level, everything you use, from food to paper to any type of consumer product (and the packaging all this comes in) takes energy to produce -- energy use that results in greenhouse gas emissions. When you put your garbage out at the curb, you are also "throwing out" this energy, and the greenhouse gas emissions from that energy use are included in your personal emissions total. When paper products are thrown out, in addition to the emissions from energy used to make them, we also count the effect on carbon dioxide of having to cut down the trees needed to make such products. In addition, when organic materials like paper, food, yard waste and grass trimmings are put in a landfill and buried, they break down in a way that causes emissions of methane gas from the landfill and methane is a powerful greenhouse gas. These methane emissions are also included in your personal emissions total for the portion of your waste that is landfilled. For a given amount of waste, your emissions will be lower if you compost what you can and recycle what you can, but there is no better way to reduce greenhouse gas emissions from your household waste than to produce less garbage in the first place.