Community action/Colorado

Climate change in Colorado encompasses the effects of climate change, attributed to man-made increases in atmospheric greenhouse gases, in the U.S. state of Colorado.

In 2019 The Denver Post reported that "[i]ndividuals living in southeastern Colorado are more vulnerable to potential health effects from climate change than residents in other parts of the state". The United States Environmental Protection Agency (EPA) has more broadly reported:

"Colorado's climate is changing. Most of the state has warmed one or two degrees (F) in the last century. Throughout the western United States, heat waves are becoming more common, snow is melting earlier in spring, and less water flows through the Colorado River. Rising temperatures and recent droughts in the region have killed many trees by drying out soils, increasing the risk of forest fires, or enabling outbreaks of forest insects. In the coming decades, the changing climate is likely to decrease water availability and agricultural yields in Colorado, and further increase the risk of wildfires".

A study by Amato Evan, professor of climate sciences at the Scripps Institution of Oceanography found that the winter season in the Western United States is getting shorter and spring is starting earlier, greatly reducing the window of time in which snow is able to fall. The Environmental Protection Agency (EPA) estimates that snowpack across Colorado has diminished by 20-60% since the 1950s. This allows trees to grow higher than they would otherwise, which is linked to habitat fragmentation.

According to the EPA "Throughout the West, much of the water needed for agriculture, public supplies, and other uses comes from mountain snowpack, which melts in spring and summer and runs off into rivers and fills reservoirs. Over the past 50 years, snow has been melting earlier in the year, and more late-winter precipitation has been falling as rain instead of snow. Thus, water drains from the mountains earlier in the year. In many cases, dams capture the meltwater and retain it for use later in the year. But upstream of these dams, less water is available during droughts for ecosystems, fish, water-based recreation, and landowners who draw water directly from a flowing river".

According to the EPA "Rising temperatures also increase the rate at which water evaporates (or transpires) into the air from soils and plants. Unless rainfall increases to the same extent as evaporation, soils become drier. As a result, the soil retains more water when it rains, and thus less water runs off into rivers, streams, and reservoirs. During the last few decades, soils have become drier in most of the state, especially during summer. In the decades to come, rainfall during summer is more likely to decrease than increase in Colorado, and periods without rain are likely to become longer. All of these factors would tend to make droughts more severe in the future".

In particular, climate change has reduced the annual flow of Colorado River in the 21st century by almost 20 percent compared to the 20th. The decline has been linked to a reduction in the mountain snowpack through evaporation. Such a change is significant because the river supports 40 million people's water consumption throughout the West and $1 trillion in economic activity.

Colorado's agricultural sector "accounts for 9% of Colorado’s greenhouse gas emissions, or approximately 11.4 million metric tons of CO₂."

Implementing regenerative agricultural practices in the state has the potential to remove 23.15 billion tons of CO₂ from the atmosphere by 2050. Use of cover crops is increasing. A collaboration between Boulder County Parks and Open Space and Colorado State University is working to develop techniques to improve soil health and carbon sequestration. State level support for soil health is under discussion.

Climate change is expected to affect human health as changing environmental conditions promote the spread of infectious diseases. Models to predict future mosquito distribution indicate longer breeding seasons, which in turn, result in an increase in the abundance of mosquitoes with likely climate scenarios. Vector-borne diseases such as the West Nile Virus (WNV) are influenced by changes in weather conditions such as temperature, precipitation, and humidity, which create ideal breeding grounds for mosquitoes. Shifting hydrologic conditions can alter the incidence of vector-borne disease as an increase also affects the number of WNV cases seen. Increased precipitation and land wetness can affect the transmission of mosquito-borne diseases similar to WNV. Shifting hydrologic conditions can alter the incidence of vector-borne disease as increased precipitation and land wetness can affect the transmission of mosquito-borne diseases As researchers have come to realize, biological systems are sensitive to small changes in seasonal temperatures, including the spread of infectious disease. Although changes in climate and weather patterns have the ability to contribute to more frequent outbreaks of WNV, local environmental conditions also play a role.

WNV is an infectious disease that is spread primarily by mosquitoes. WNV is concerning as it has the capability to cause inflammation in the brain and body tissues. Most individuals do not suffer from extreme symptoms, but mild symptoms include skin rashes, body aches, fevers, and headaches making it difficult to differentiate between a cold or allergic reaction when evaluating one's symptoms. Severe cases of WNV are neuroinvasive, causing symptoms such as encephalitis and meningitis. From 1999 to 2018, Colorado had the fourth-highest incidence of neuroinvasive WNV in the United States.

Cases of WNV have been reported in Colorado every year since 2002. The 5-year historical average of WNV cases in Colorado indicates that most cases appear in late summer months, primarily August and September. Currently, there is no vaccine for WNV, and hospitalization is often required for patients experiencing symptoms. People often outdoors where mosquitoes are present should take precaution by wearing protective clothing and mosquito spray.

In December 2019, the Colorado Air Quality Control Commission strengthened inspection requirements for oil and gas production facilities and for pipelines in order to reduce greenhouse gas emissions.

• List of U.S. states and territories by carbon dioxide emissions
• Plug-in electric vehicles in Colorado
• Climate change in the United States

• Gonzalez, P.; G.M. Garfin; D.D. Breshears; K.M. Brooks; H.E. Brown; E.H. Elias; A. Gunasekara; N. Huntly; J.K. Maldonado; N.J. Mantua; H.G. Margolis; S. McAfee; B.R. Middleton; B.H. Udall (2018). "Southwest". In Reidmiller, D.R.; C.W. Avery; D.R. Easterling; K.E. Kunkel; K.L.M. Lewis; T.K. Maycock; B.C. Stewart (eds.). Impacts, Risks, and Adaptation in the United States: Fourth National Climate Assessment, Volume II (Report). Washington, DC, USA: U.S. Global Change Research Program. pp. 1101–1184. doi:10.7930/NCA4.2018.CH25.—this chapter of the National Climate Assessment covers Arizona, California, Colorado, New Mexico, Nevada, and Utah

Colorado is a landlocked state in the Mountain West subregion of the Western United States. It is one of the Mountain states, and part of the Southwestern United States, sharing the Four Corners region with Arizona, New Mexico, and Utah. It is also bordered by Wyoming to the north, Nebraska to the northeast, Kansas to the east, and Oklahoma to the southeast. Colorado is noted for its landscape of mountains, forests, high plains, mesas, canyons, plateaus, rivers, and desert lands. It encompasses most of the Southern Rocky Mountains, as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. Colorado is the eighth-largest U.S. state by area and the 20th by population. The United States Census Bureau estimated the population of Colorado to be 5,957,493 as of July 1, 2024, a 3.2% increase from the 2020 United States census.

Water in Colorado is of significant importance, as the American state of Colorado is the 7th-driest state in America. As result, water rights generate conflict (for example, see Colorado River Water Conservation District v. United States), with many water lawyers in the state.