Member Resources

Changing Climate and Drought in Prescott Area

by | Feb 13, 2025 | ,

We frequently drive north on Highway 89 as we head to the Grand Canyon, Williams or Flagstaff. On one of our first trips after moving to Prescott Valley in 2020, the sight along the road north of Paulden shocked me. Large numbers of Juniper trees in vast sections of the forest were dying or already dead. It was clear drought was impacting them.

The US Forest Service reported in 2021, approximately 50,000 to 100,000 acres of junipers had been affected. Mortality was reported to be 5-30% of trees with larger pockets from 1 to 15 acres even higher. The impact on our iconic juniper-pinyon forests is a sad reminder of climate change.

Trying to better understand the cause of our drought, I analyzed our historical weather looking at Annual Average Highs & Lows, Annual Days with Precipitation, Annual Precipitation and Annual Snow (see attached spreadsheet). The results surprised me a bit. Our rising temps were more strongly driven by gradually increasing lows than highs. While high temperatures have been rising steadily in the last 45 years, they have only in the last five years exceeded highs experienced in the 1930s and 1940s.

In addition, precipitation is not abnormally low. It is in a range experienced regularly. NOAA Research has confirmed this observation concluding in November 2024, the drought is driven from rising temperatures and not lack of rainfall. The rising temperatures increase evaporation and stress the soil leading to an increased need for precipitation. So “normal” precipitation is not enough. The rising temperatures may have also led to a change in how we are getting precipitation. The amount of snowfall has been low relative to history for the last 25 years. Snow and the way it slowly melts into the ground is the best type of precipitation for soil. Changing the form of precipitation also contributes to the stress on the land.

The climate and weather are definitely changing. Nature will continue to adapt over time. What the future consequences of these changes are is yet to be seen. The juniper forests warn us though that some change will be hard and costly.

References

* https://www.fs.usda.gov/detail/prescott/news-events/?cid=FSEPRD904406
* https://www.extremeweatherwatch.com/cities/prescott/average-temperature-by-year
* https://www.extremeweatherwatch.com/cities/prescott/most-yearly-snow
* https://www.extremeweatherwatch.com/cities/prescott/most-yearly-precipitation
* https://www.nps.gov/articles/pinyon-juniper-woodlands-climate-change-and-literature-cited.htm
* https://research.noaa.gov/new-study-finds-heat-not-lack-of-precipitation-is-driving-western-u-s-droughts/

NASA – A Year in the Life of Earth’s CO2 on YouTube

by | Feb 12, 2025 | ,

An ultra-high-resolution NASA computer model has given scientists a stunning new look at how carbon dioxide in the atmosphere travels around the globe.

Plumes of carbon dioxide in the simulation swirl and shift as winds disperse the greenhouse gas away from its sources. The simulation also illustrates differences in carbon dioxide levels in the northern and southern hemispheres and distinct swings in global carbon dioxide concentrations as the growth cycle of plants and trees changes with the seasons.

The carbon dioxide visualization was produced by a computer model called GEOS-5, created by scientists at NASA Goddard Space Flight Center’s Global Modeling and Assimilation Office.

The visualization is a product of a simulation called a “Nature Run.” The Nature Run ingests real data on atmospheric conditions and the emission of greenhouse gases and both natural and man-made particulates. The model is then left to run on its own and simulate the natural behavior of the Earth’s atmosphere. This Nature Run simulates January 2006 through December 2006.

While Goddard scientists worked with a “beta” version of the Nature Run internally for several years, they released this updated, improved version to the scientific community for the first time in the fall of 2014.

This video is public domain and can be downloaded at: http://svs.gsfc.nasa.gov/goto?11719

Course Module – Climatology-Phenology – Part One

by | Feb 12, 2025 | ,

Objectives:
* Define phenology and explain its role as an indicator of climate change
* Summarize basic principles of ecology and how they relate to phenology
* Describe the difference between weather and climate and describe climate change through time
* Identify the phenology of plants, major phenophases (leaves, flowers, fruits) and the importance in nature