From gasoline to food and clothing to healthcare, consuming things and services creates greenhouse gas emissions. We already know that making, growing, and transporting goods or services produce emissions all over the world. But how much of all those consumption emissions worldwide are in Minnesota?
Consumption-based emission inventory
The consumption-based emission inventory (CBEI) is a method used to estimate the greenhouse gas (GHG) emissions that are created when we consume the goods and services we buy every day. This approach accounts for emissions through a product or service’s entire life cycle. A CBEI includes everything that households and governments consume, as well as life-cycle GHG emissions resulting from any goods that businesses have not yet sold or from capital equipment. The model breaks down emissions by five life-cycle phases:
- Production (no matter where the emissions occur in the world)
- Pre-purchase transportation
- Wholesale and retail
To get a clearer picture of Minnesotans’ total GHG emissions, the MPCA recently completed a CBEI. The model uses Minnesota-specific data from 2012.
Consumption and in-boundary: two complementary inventories
The CBEI complements the “in-boundary” GHG inventory that Minnesota conducts every two years. The in-boundary inventory is required by law and measures GHGs emitted within the state's geographical boundaries. This includes any agriculture or manufacturing emissions, regardless of where the goods are ultimately consumed. For example, the in-boundary inventory counts life-cycle emissions from a turkey raised in Minnesota but exported and eaten in New York.
The in-boundary inventory is good for looking at our industrial sectors in Minnesota and developing priorities or programs for GHG reductions in those sectors. To explore Minnesota's in-bound inventory, visit MPCA's Greenhouse gas emissions data web page.
The CBEI offers different categories or “buckets" of emissions than the traditional in-boundary inventory. For example, the life-cycle emissions from the turkey that went to New York aren’t counted in the CBEI, but the life-cycle emissions from a coat made in China and bought in Minnesota are.
The CBEI divides consumption-related emissions into about 20 categories such as food and beverages, electronics, and household supplies and furniture. Dividing up the emissions a little differently helps us see the GHG-reducing potential of different actions. The CBEI is particularly useful for looking at household and citizen consumption choices and behaviors, and prioritizing those for emissions reductions.
Comparing results of the two inventories
The two inventories are developed using different methodologies and yield different perspectives on GHG drivers. Both perspectives are helpful.
- Minnesota is a net exporter of GHGs: Emissions from agricultural and other goods we make and export are slightly higher than those from the goods and services we import.
- The majority of our emissions are made and consumed in Minnesota.
- Minnesotans’ consumption is responsible for 61.2 million metric tons of “imported” GHGs that have not been previously estimated in state inventories.
About our consumption emissions
The CBEI allows a glimpse into the relative effect on GHG emissions of different categories of consumption in Minnesota and also which life-cycle phase most of those emissions are coming from.
- Over three-quarters of Minnesotans’ consumption emissions are from household consumption.
- Just over half of our consumption emissions are from goods or services made in Minnesota. The other 46% of consumption-based emissions are from production of goods we import from elsewhere in the U.S. or from other countries.
Informing materials and climate policy and action
The CBEI can help those looking to minimize the climate impacts of materials and consumption. Based on which categories and which part of the life cycle have the largest impacts, materials management policies and actions can be prioritized. Where impacts are primarily in the use phase, that may suggest a need for efficiency gains, or reduction in overall use. Where impacts are primarily in production, that might point to toward a need for cleaner production, extending the life of items, and in some cases, reduction of demand.
- The CBEI highlights that most climate impacts are from the production, and in some cases, the use of goods -- not from the waste that consumption generates (i.e., end-of-life, post-consumer disposal impacts). Note: The CBEI does not specifically account for the GHG impacts of Minnesota’s recycling efforts. To the extent that industries include recycled feedstock in their manufacturing, recycling impacts are included in the CBEI’s underlying data. Most GHG benefits from recycling arise from reduced need for virgin materials. Oregon DEQ conducted an additional analysis estimating additional GHG reduction from that state’s recycling. The MPCA has not undertaken such an analysis at this time.
- The CBEI highlights new levers for climate action related to consumption choices. For example, how much might repair and reuse reduce GHG? The CBEI reveals that increasing repair and reuse to double the useful life of clothing and household furnishings and supplies would be equivalent to increasing vehicle efficiency by 15%. Each would reduce GHG emissions by about 2.5 million metric tons of CO2e.
- The CBEI can model emissions variations from any change in consumption of types of goods or services. Currently the CBEI tool is accessible only by MPCA staff, but it may also be useful for local governments or other groups.
How the CBEI can help Minnesotans
Compared to the in-boundary inventory’s sector-based categories (agriculture, industrial, electricity generation, etc.), the CBEI categories reflect typical household consumption (furnishings, clothing, electronics, food). This may help individuals better understand how their consumption choices can reduce GHG pollution.
Technical documentation of CBEI analysis
The MPCA used an approach and CBEI model pioneered by the Oregon Department of Environmental Quality and its consultants from the Stockholm Environment Institute in 2005 and 2010. Rather than replicate the in-depth technical documentation for the model, refer to Appendix B, sections 1, 2 and 4 in Oregon’s sector-based and consumption-based greenhouse gas emissions report.