Final Climate Report. Sunflower Allotment Grazing Analysis. July 2015

Transcription

1 Final Climate Report Sunflower Allotment Grazing Analysis July 2015

2 Affected Environment Climate on the allotment is characterized by a bimodal precipitation pattern with about sixty percent occurring as frontal systems in winter from December to March and about forty percent occurring as monsoons in summer from July to September. Summer storms can be more intense than winter storms, but are generally of shorter duration and smaller aerial extent. According to the National Oceanic and Atmospheric Administration s (NOAA) National Climatic Data Center data, there has been a marked upward trend in the globally averaged annual mean surface temperature since the mid-1970s (Shein 2006). The Federal Advisory Committee Draft Climate Assessment Report is projecting higher temperatures and lower precipitation for the Southwestern United States (Garfin, et al. 2013). New modeling efforts for the North American monsoons indicate that the amount of monsoon moisture will change little; however, the monsoons will be delayed and most of the precipitation will come late in the season during September through October (Cook and Seager 2013). The nearest climate gages to the project area with current data are Roosevelt 1WNW and Mesa. The period of record for Roosevelt 1WNW is 1905 to present (WRCC 2013), and the average annual precipitation is inches (NOAA 2013). Of the last ten years (2003 to 2012), the data indicate seven years had below average precipitation (NOAA 2013). For the period 2002 to 2011, the temperature was above average eight of the ten years (WRCC 2013). The period of record for Mesa is 1896 to present (WRCC 2013), and the average annual precipitation is 9.49 inches (NOAA 2013). Of the last ten years (2003 to 2012), the data indicate six years had below average precipitation (NOAA 2013). Average high and low temperatures for Mesa, was 43 degrees Fahrenheit in January and 81 degrees Fahrenheit in July during a 14 year period (observing the coolest month January and warmest month July), according to NOAA. Observing temperature averages from years : January experienced its lowest average at 38.6 degrees Fahrenheit in year 2013 and July experienced its highest average at 83.8 degrees Fahrenheit in year 2003 (Table 1) ( Page 2 of 5

3 Table 1: 14 year temperature ( ) averages in Mesa Year Average January Temperature ( F) Average July Temperature ( F) Assumptions Associated with Climate Change U.S.D.A. Strategic Plan for 2010 to 2015 sets a departmental goal to ensure our national forests and private working lands are conserved, restored, and made more resilient to climate change, while enhancing our water resources. As a measure of this goal, all National Forests are to come into compliance with a climate change adaptation and mitigation strategy. The Plan and A Roadmap for Responding to Climate Change has been developed and is available on the agency s website at The Roadmap integrates land management, outreach, and sustainable operations accounting. It focuses on three kinds of activities: assessing current risks, vulnerabilities, policies, and gaps in Page 3 of 5

4 knowledge; engaging partners in seeking solutions and learning from as well as educating the public and employees on climate change issues; and managing for resilience, in ecosystems as well as in human communities, through adaptation, mitigation, and sustainable consumption strategies. To measure agency progress in moving toward this goal, a Performance Scorecard has been implemented. According to the EPA, 20% of methane in the world comes from livestock (which includes cattle). There are approximately 1.5 billion cattle on Earth. Only 10% of the world s cattle are in the USA. The USA is less than 2% of the surface of the Earth. The entire National Forest System is 193 million acres which is only 8.4% of the USA. The Tonto National Forest is less than 2% of the entire National Forest System, and the Sunflower Allotment is only 5% of the Tonto National Forest. It is impractical to analyze the global contribution of CH4 to climate change from less than 550 cattle on such an insignificant percentage of the earth. It has been calculated that methane loss by ruminants only accounts for a very low percentage of total global methane, even less than that contributed by termites (Holter and Young, 1992). It would be difficult to separate effects of livestock emissions from those produced by other human activities, such as passenger vehicles and off-road vehicles traveling on roads in the analysis area, industrial activities such as mining, and outflow from major metropolitan areas such as Phoenix, Arizona, which lies approximately 30 miles south of the analysis area. Livestock grazing may or may not affect climate by altering the abundance or type of carbonsequestering vegetation available on the landscape (Brown et al. 1997, Asner et al. 2004, Archer and Predick 2008). Implementation of best management practices and utilization guidelines is anticipated to mitigate this effect across the analysis area. Climatic fluctuations, on the other hand, can have a profound effect on livestock grazing. Implementing an adaptive management strategy would be critical for responding to these fluctuations by adjusting stocking rates, as needed, in periods of below average or above average precipitation to meet desired conditions for all resources. Removal of livestock from the allotments through selection of a no grazing alternative would reduce emissions slightly; however, it would be difficult to measure this change. Emissions would continue to be generated from neighboring allotments in the analysis area. Eliminating grazing pressure on vegetation may also have a slight benefit for carbon sequestration; again, this would be difficult to measure on such a small scale. Environmental Effects Since it is nearly impossible to determine measurable effects of authorizing grazing on the Sunflower Allotment on climate change, there are no direct or indirect effects to climate change to analyze for this project. Thus, there would be no cumulative effects to analyze. Page 4 of 5

5 Citations Archer, S., and Predick, K Climate change and ecosystems of the Southwestern United States. IN: Rangelands, Asner, G. P.; Elmore, A. J.; and Olander, L. P Grazing systems, ecosystem responses, and global change. IN: Annual Review of Environmental Resources, 2004: Brown, J. K Fire regimes and their relevance to ecosystem management. Presented at Society of American Foresters/Canadian Institute of Forestry Convention. September 18-22, Anchorage, Alaska. Cook, B. I. and R. Seager Draft. The response of the North American monsoon to increased greenhouse gas forcing. In: Journal of Geophysical Research. November 8, p. Garfin, G., G. Franco, H. Blanco, A. Comrie, P. Gonzalez, T. Piechota, R. Smyth, R. Waskom Chapter 20 Southwest in: Federal Advisory Committee Draft Climate Assessment Report. (retrieved February 4, 2013). Federal Advisory Committee Draft Climate Assessment Report. Holter JB, Young AJ Methane Prediction in Dry and Lactating Holstein Cows. Dairy Science.) Shein, K. A., ed State of the climate in Bulletin of the American Meteorological Society, 87, S1-S102. NOAA Local Service Assessment: January 2010 Arizona Winter Storms. National Weather Service. 77 pp. NOAA National Weather Service Forecast Office, Phoenix, AZ. 1 WNW National Climatic Data Center. Western Regional Climate Center Arizona. (February 2013) Page 5 of 5