Greenhouse gases (GHGs) are gases that warm the atmosphere and surface of the planet, leading to changes in the Earth’s climate. The conventional GHGs are carbon dioxide (CO2), nitrous oxide (N2O), methane (CH4), sulfur hexafluoride (SF6), and two classes of compounds known as hydrofluorocarbons (HFCs) and perfluorocarbons (PFCs). Most GHG emissions are CO2, but the other GHGs have very strong warming effects. To compare all the GHGs in common terms to CO2, emissions are multiplied by their global warming potential (GWP) to produce CO2-equivalent (CO2-e) emissions.
Fossil fuel use is the largest source of CO2 emissions and also emits CH4 and N2O. Most fossil fuel is used for generating electricity and fueling vehicles. Energy policies have reduced GHG emissions.
Animal and crop agriculture emit most of the CH4 and N2O emissions. Landfills are also a source of CH4. Most of the HFC emissions are from air conditioning. PFCs and SF6 are a small portion of GHG emissions, and are from technical applications.
High global warming potential greenhouse gases (HFCs, PFCs and SF6) are especially strong greenhouse gases and policies target reducing their use.
Emission reduction goals
Estimating greenhouse gas (GHG) emissions is important for protecting and improving the environment and enhancing human health because it provides data to inform policy decisions that reduce Minnesota’s contribution to global air pollution.
In 2007, the Minnesota Legislature passed the Next Generation Energy Act, which set goals for reducing GHG emissions in the state and goals for renewable energy use and energy conservation. The Next Generation Energy Act set a goal that would reduce GHG emissions in 2015 to a level 15% below the 2005 level, and also for 2025 and 2050 emissions levels to be 30% and 80%, respectively, below the 2005 emission levels (Minn. Stat. § 216H.02).
The Greenhouse Gas Emissions Reduction report highlights progress toward these goals.
Highlights from 2012 data
Greenhouse Gas Emissions Reduction - Biennial Report (January 2015)
Greenhouse gas emissions
GHG emissions in 2012 totaled 154 million CO2-equivalent tons (CO2-e). Between 2005 and 2012, GHG emissions from Minnesota declined by 11 million CO2-e, or about 7%, with the most significant reductions coming from electric power utilities and transportation energy use.
In 2012, about 31% of the GHG emissions were from the consumption of electricity and about 25% of emissions were from transportation. In late 2011, the state’s largest coal-fired unit at Xcel Energy’s Sherburne County generation station suffered a disabling explosion and did not resume operation until late 2013.
Emissions by economic sector
Emissions are grouped by into economic sectors: agricultural, commercial, electric utility, industrial, residential, transportation, and waste.
Indicators and trends
Measures of GHG emission intensity are useful in understanding how emissions change in relation to other Minnesota trends. Indicators related to GHG emissions include population, economic outputs and energy consumption. GHG emissions have generally declined, indicating a shift toward a less greenhouse gas intense economy. Our population also continues to grow while emissions decline.
The recession can be seen in the emissions and economic activity in 2009. Industrial output and overall energy consumption declined, reducing greenhouse gas emissions. With economic recovery, the gross state product increased.
Highlights from 2010 data
GHG emissions in 2010 totaled 155.6 million CO2-equivalent tons (CO2-e). Between 2005 and 2010, GHG emissions from Minnesota declined by 5 million CO2-e, or about 3%, with the most significant reductions coming from electric power utilities and transportation energy use. The full report contains more detail.
In 2010, about 32% of the GHG emissions were from the generation of electricity and about 24% of emissions were from transportation fuels. The Next Generation Energy Act established a goal to reduce GHG emissions to a level 15% below 2005 emissions by 2015; in 2010, GHG emissions were about 3% less than 2005 emissions.
GHG emissions in 2010 totaled 155.6 million CO2-equivalent tons (CO2-e). Between 2005 and 2010, GHG emissions from Minnesota declined by 5 million CO2-e, or about 3 percent, with the most significant reductions coming from electric power utilities and transportation energy use. The full report contains more detail.
Tracking progress on Minnesota greenhouse gas emissions
Greenhouse gas emissions by economic sector
Emissions are grouped by sector (agricultural, commercial, electric generation, industrial, residential, transportation, and waste) and into major activity groups (energy use and fuel production, agricultural process, industrial process, and waste management emissions).
Greenhouse gas emissions from Minnesota by economic sector: 1970-2010
Greenhouse gas emissions from Minnesota by economic sector: 2010 percentages of total emissions
Emissions from transportation and electric power generation comprised roughly 56% of all Minnesota GHG emissions in 2010.
Electric generation sector
Between 2005 and 2010, emissions of GHGs from electricity generation declined by 7 million CO2-equivalent tons, or about 13%. Emissions from coal combustion account for about 65% of greenhouse gas emissions from electricity generation, and have declined in recent years.
Greenhouse gas emissions from the electric generation sector: 1970-2010
While most of the electricity consumed in Minnesota is generated within the state, some electricity is purchased from utilities outside the state borders. In 2010, imported electricity supplied 26% of the electricity consumed in the state. This imported electricity is included as a source of greenhouse gas emissions.
Some sources of electricity are not shown in this figure because they do not generate GHG emissions. Nuclear power is a significant source of electricity generated in Minnesota, and electricity from wind turbines is an expanding source of energy.
Greenhouse gas emissions from transportation sector in Minnesota
In 2010, GHG emissions from transportation were an estimated 37.4 million CO2-equivalent tons. Between 2005 and 2008, total transportation emissions decreased by 4.2 million CO2-equivalent tons, or by about 10%.
Indicators and explanation of trends
Measures of GHG emission intensity are useful in understanding how GHG emissions change in relation to other Minnesota trends. Indicators related to GHG emissions include population, economic outputs and energy consumption.
The trend in emissions in relation to each of these indicators is shown in the figure below as relative to 1990 levels of emission intensity.
Indicators of greenhouse gas emission intensity
The decline in Minnesota’s economic output and resulting decrease in energy were the primary drivers in the decrease in GHG emissions in 2009. The GHG intensity of Minnesota’s economy has steadily declined. The GHGs/gross state product indicator shows that Minnesota’s economy is increasingly efficient in terms of GHG emissions per economic output. The GHG intensity of Minnesota’s energy has remained fairly constant because our energy sources are still predominantly fossil fuels. The slight decrease in the GHGs/MMBtu indicator shows the effect of energy efficiency and renewable energy.
A report on statewide progress toward greenhouse-gas-reduction goals enumerated in the Next Generation Energy Act, including a summary of emissions by economic sector and by major activities, with long term trends and social and economic indicators. (June 2009)
This spreadsheet contains the summarized data used in the report (1970-2006). Keys for organizing the data into the same economic sectors and activities as in the report are included. It is important to note that the numbers in this spreadsheet and subsequent iteration of the analysis are subject to change if methods or original data are updated.