Climate change has had a number of impacts on the US state of Montana. Heat waves are becoming more common, snow is melting earlier in the spring, and trees are dying as a result of drought, forest fire, and increased prevalence of forest insects. In the next few decades in Montana, climate change is most likely to impact water availability, agricultural yields, and wildfire risk.

State and local governments have taken legislative steps, such as establishing a renewable energy portfolio and creating climate action plans, to mitigate the effects of climate change.

Impacts

Water resources

According to the IPCC, possible effects on water systems for the Montana region include less water available in some areas. Warming in mountain states is projected by the IPCC to cause decreased snowpack, more winter flooding, and reduced summer flows. This may increase competition for water resources.

Montana is a headwater state, and consequently, potential climate change effects that impact Montana’s water resources reach far beyond the state borders.

The Department of Environmental Quality, Montana, has determined that climate change will affect essential water resources in Montana as water quality and ecosystems may be compromised when contaminants and sediment are carried by spring run-off at unnatural times.

A report from the University of Lethbridge found climate change may alter stream flow and water supply volume by lowering snowpack which may cause low reservoir storage in the spring and dangerously low flows in the summer making perennial streams potentially intermittent

 The Montana Wildlife Conservation Society is concerned that warming water may also change patterns of some species such as native bull trout require colder water than other fish and would have a difficult time surviving if waters warmed.

Forest resources

Montana’s forests sequester up to 23.1 million metric tons of carbon dioxide equivalents annually—approximately 62 percent of the state’s gross emissions. The state also contains 8.9 million acres thought suitable for afforestation with a potential sequestration capacity of up to 15 million metric tons.

The impacts of climate change upon Montana’s forests could result in feedback: assuming a shift to a ‘drier’ precipitation and temperature scenario, the sequestration capacity of Montana’s high-elevation forests could be reduced or even eliminated entirely.

Agriculture

The effects of climate change on agriculture varies among regions and Montana’s agricultural production may not change substantially as global temperatures continue to increase over the short term according to the IPCC Fourth Assessment Report. Major challenges are projected for crops that are near the warm end of their suitable range or depend on highly utilized water resources .

Human health

Adverse health impacts from climate change have already been documented, and are expected to increase during the twenty-first century. Montanans will experience health impacts from increased temperatures and decreased stream flows that are similar to those in other parts of the country. Decreased summer stream flows will lead to heavier concentrations of pollutants including toxic metals, microbes and nutrients.[8] Higher temperatures and increased forest fires will adversely affect air quality, increasing incidences of asthma, lung and heart disease. On average, climate change has already extended the allergy season by 20 days annually since 1950.

State adaptation and mitigation
Renewables

In April, 2005, Montana established a renewable energy portfolio which requires all public utilities to derive at least 15% of their electricity from renewable energy resources by 2015. Part of Montana’s renewable energy development plan is to stimulate rural economic development by requiring public utilities to buy renewable energy credits and electricity generated by community-based energy utility companies.

From 2010 to 2014, public utility companies in Montana must purchase 50 MW from these rural community-based utility companies. Beginning in 2015, that figure will grow to 75 MW. Any utility company serving more than 5,000 people is required to create a renewable energy standard which promotes renewable energy development, with specific emphasis on rural economic development.

Currently, Montana’s renewable energy is derived primarily from wind energy, geothermal energy and solar energy. Montana offers many tax incentives and loan programs for individuals and businesses to promote renewable energy development at all levels in both the private and the public sector.[11] This renewable-energy promoting legislation includes production incentives, utility grants and loans, a green power program, property tax exemptions, and production tax reductions.

In 2009, Montana received $10.3 million in federal Recovery Act funding to improve the energy efficiency of state buildings and expand renewable energy use and recycling infrastructure in the state.

The funds will also be used for grants to encourage use of new clean energy technologies that have moved into the production phase but are not yet well known or utilized in the state. Montana Department of Environmental Quality (DEQ) will also extend low-interest loans to consumers, businesses, and nonprofit organizations to install various renewable energy systems, including wind, solar, geothermal, hydro and biomass.

Wind Montana is ranked among the top five states in the nation for wind power generation potential. As of 2009, Montana produced 820,924 MWh of wind-generated electricity, which represented more than three percent of all electricity generated in Montana that year. 

Montana is ranked first in the nation for wind speed of class 3 and above, with the majority of wind sites located in areas of low population, near communities that favor wind energy development. Montana Department of Environmental Quality maintains monitoring data from current wind-powered facilities and provides that data to people who are interested in wind energy investment opportunities in the state. 

The Energy Promotion and Development Division “facilitates a wind and transmission working group that consists of industry, government, academic and other stakeholders. The group has been meeting quarterly since April 2008 and it convenes to identify obstacles to transmission and wind development and to develop strategies to overcome those obstacles.”

Large-scale wind farms in Montana currently include Glacier wind farm near Shelby, Judith Gap wind farm in Wheatland County, Diamond Willow wind farm near Baker, MT, and Horseshoe Bend Wind Park near Great Falls. Detailed wind power maps are available on MDEQ’s official site.

Geothermal In May, 2005, the State of Montana, Department of Energy (DOE) and Sage Resources of Missoula, Montana established the Montana Geothermal Program. Montana’s potential for large-scale geothermal energy development is still being evaluated. DOE’s Geopowering the West program indicates that Montana has more than 25,000 square miles of high-potential sites and areas.

Currently, Montana has 15 high-temperature sites located near White Sulphur Springs, Helena, Ennis, Bozeman, Butte and Boulder, and more than 50 designated geothermal areas of varying temperatures across the entire state. A total of twenty-seven known sites have surface temperatures ranging from 110 °F to above 149 °F, and current temperature estimates for deep reservoirs exceed 350 °F. An interactive topographic map providing details about Montana’s principal geothermal sites is available on MDEQ’s official site.

Solar Currently, most of Montana’s solar energy projects are undertaken at the residential or small-scale municipal level in homes, ranches, schools, community buildings and business. The feasibility of larger-scale solar energy generation facilities in Montana continues to be researched.

Eastern Montana receives an annual average of 5 hours of full sun, and western Montana receives an annual average of 4.2 hours, so Montana has adequate solar resources to support more widespread development of solar energy in the future.

The State of Montana currently offers numerous tax incentives and revolving loan programs to encourage solar energy development projects. Details of those programs can also be found on MDEQ’s official site.