Climate Impacts in Northern Arizona
Climate change is already causing adverse effects on Southwestern communities’ health and economies due to increases in temperature, drought, and wildfirei. The changing climate is linked to rising concentrations of greenhouse gases such as carbon dioxide, methane and hydrofluorocarbons (HFCs) in the atmosphere, which insulate the planet and cause it to warm. It has been shown that reducing these heat-trapping gas emissions will reduce the speed at which the planet is warming, thus mitigating the expected threats to communities and the environment.
There is support for climate change action in Arizona: According to a studyii conducted by the University of Arizona and Stanford University, 70 percent of Arizona residents believe that the U.S. and Arizona governments should take action on climate change by limiting greenhouse gas emissions.
To lead the way in Arizona, the City of Flagstaff is developing a community-driven Climate Action and Adaptation Plan to set decreased emission goals and increase the resilience in our community to climate change impacts.
Extreme Weather in Flagstaff
Flagstaff is already experiencing the impacts of climate change like extreme weather. These events are expected to increase, with higher intensity. This story map explores the drought, fire, flood, heat and wind events Flagstaff has experienced in its recent past.
Observed Regional Changes
Over the past few decades, the land where the Navajo Nation resides has become much hotter and drier. Streams that flowed in the nineteen eighties are now dry washes that never, or rarely flow. These hotter temperatures increase evaporation, making the soil drier and unsuitable for most plants. As a result, sand dunes are growing. to learn more about the impacts of climate change on Navajo Nation watch this video produced by the U.S. Geological Society.
Rate of Change
Over the course of Earth's history the climate has changed many times, experiencing climactic shifts from unbearably cold ice ages to periods of intense heat and drought. Today, it is not the fact that the climate is changing that is so alarming, but the rate at which this change is taking place and the fact that humans are the primary cause
In the past, changes in Earth's climate have happened over long periods of time, which gives time for its inhabitants to adapt. In instances when abrupt changes have occurred, they have have been accompanied by mass extinctions or drastic changes to Earth's environment.
What is causing the change?
Greenhouse gases like carbon dioxide, methane, hyroflurocarbons (HFCs), and water vapor trap heat within the atmosphere, acting like an insulating blanket. Increasing greenhouse gas concentrations in the atmosphere thickens this blanket, which in turn, makes it more difficult for heat to escape and causes the planet to warm. Over the past 50 years, humans have been adding carbon dioxide to the atmosphere at an alarming rate and the temperature has been rising:
Caption: Global annual average temperature (as measured over both land and oceans) has increased by more than 1.5°F (0.8°C) since 1880 (through 2012). Red bars show temperatures above the long-term average, and blue bars indicate temperatures below the long-term average. The black line shows atmospheric carbon dioxide (CO2) concentration in parts per million (ppm). While there is a clear long-term global warming trend, some years do not show a temperature increase relative to the previous year, and some years show greater changes than others. These year-to-year fluctuations in temperature are due to natural processes, such as the effects of El Niños, La Niñas, and volcanic eruptions.
Figure source: updated from Karl et al. 2009. Found at (http://nca2014.globalchange.gov/highlights/report-findings/our-changing-climate#tab2-images)
Climate models are used to predict the future climate based on the dynamics of the climate system and trends in carbon emissions. Reducing carbon emissions can greatly decrease global warming, as seen below. This is what it is important to reduce your impact now.
Increased temperatures have significant effects on weather systems, leading to an expected increase in extreme weather events including heat waves, drought, and fires. Warmer temperatures also mean larger and more ferocious hurricanes, downpour events, and flooding. Visit the National Climate Assessment website for more details.
Caption: Maps show projected change in average surface air temperature in the later part of this century (2071-2099) relative to the later part of the last century (1970-1999) under a scenario that assumes substantial reductions in heat trapping gases (B1) and a higher emissions scenario that assumes continued increases in global emissions (A2). (See Appendix 3: Climate Science, Supplemental Message 5 for a discussion of temperature changes under a wider range of future scenarios for various periods of this century).
Figure source: NOAA NCDC / CICS-NC
Do you have questions about climate change, the science behind it, and what to do about it? The National Climate Assessment has compiled a list of Frequently Asked Questions to help answer your questions.
References and further reading
[i] Garfin, G., G. Franco, H. Blanco, A. Comrie, P. Gonzalez, T. Piechota, R. Smyth, and R. Waskom, 2014: Ch. 20: Southwest. Climate Change Impacts in the United States: The Third National Climate Assessment, J. M. Melillo, Terese (T.C.) Richmond, and G. W. Yohe, Eds., U.S. Global Change Research Program, 462-486. doi:10.7930/J08G8HMN. http://nca2014.globalchange.gov/report/regions/southwest
[ii] Liverman, D., Garfin, G.M., Doster, S., Overpeck, J.T., Machlis, G. (2015). Arizona’s views on climate change-Executive summary. Institute of the Environment. http://www.environment.arizona.edu/climate-survey