Climate change impacts in our backyards:  the Southwest


New Mexico is under such severe drought this July that state politicians are appealing to the federal government for drought relief for seven counties.  Meanwhile, the rain that does fall occurs in strenuous downpours that damage agricultural crops.  Record-breaking drought has hit southern Texas.  And California is in such dire straits with water shortages that Interior Secretary Ken Salazar flew out last week to hear directly from farmers and other water-dependent groups.  For the American Southwest, prolonged drought with critical water shortages and searing heat are the climate change signatures.  This 6th post in our series delving into Global Climate Change Impacts in the United States takes a look what is happening now and what might be in store.

CSW Series on Global Climate Change Impacts in the United States:  Part 6

The Southwestern United States

A convergence of the highest population growth rates in the nation and the most rapid warming compared with other regions makes the American Southwest especially vulnerable to climate impacts.

“The fingerprints of climate change can already be seen in both natural and managed ecosystems of the Southwest.  Future impacts on the landscape are expected to be substantial, threatening biodiversity, protected areas, and ranching and agricultural lands.”  [quotes are from the June 2009 USGCRP report, Global Climate Change Impacts in the United States].

The Southwest already experiences very high summer temperatures and corresponding water and energy needs, intensified by a rapidly growing population.  Projected temperature increases for the Southwest represent augmented stresses to health, electricity, and water supply in a region that is already at risk.  As the climate warms, the current “tug-of-war among preserving natural ecosystems, supplying the needs of rapidly expanding urban areas, and protecting the lucrative agricultural sector, will be exacerbated.”

Hot, Dry, and Parched

•  Prolonged drought is emerging as the most serious risk:  drought is occurring now,  water supplies in the Southwest are already limited, and the “trend toward scarcity indicates a strong possibility of future shortages.”

o “Further water cycle changes are projected, which, combined with increasing temperatures, signal a serious water supply challenge in the decades and centuries ahead.”

o “Groundwater pumping is lowering water tables, while rising temperatures reduce river flows in vital rivers including the Colorado.  Limitations imposed on water supply by projected temperature increases are likely to be made worse by substantial reductions in rain and snowfall in the spring months, when precipitation is most needed to fill reservoirs to meet summer demand.”

o “[T]emperature increases have made the current drought in the region more severe than the natural droughts of the last several centuries…As temperatures rise, some iconic landscapes of the Southwest will be greatly altered as species shift their ranges northward and upward to cooler climates, and fires attack unaccustomed ecosystems which lack natural defenses.”

o “In California, two-thirds of the more than 5,500 native plant species are projected to experience range reductions up to 80 percent before the end of this century under projected warming.”  The potential for successful plant and animal adaptation to changing conditions does exist, but it will be “further hampered by existing regional threats such as human-caused fragmentation of the landscape, invasive species, river-flow reductions, and pollution.”  Some “rapidly changing landscapes will require major adjustments, not only from plant and animal species, but also by the region’s ranchers, foresters, and other inhabitants.”

When it’s not too dry, it’s too wet, too fast.

•  A warmer atmosphere and an intensified water cycle are likely to increase not only the likelihood of drought for the Southwest, but also the risk of flooding.  The combination of decreased snow cover on the lower slopes of high mountains and an increased fraction of winter precipitation falling as rain is likely to increase the instances of floods, with the most obvious impacts being a greater risk to human safety and infrastructure.

A few excerpts from recent news reports from this region:

Flood, drought make ag aid situation confusing

CARLSBAD (NM)  — What kind of disaster situation exists in Eddy County: an agriculture flood or a drought?  The answer: Both.

“The Loving and Malaga area recently got over 6 inches of rain at one time, and they had more rain just days later. But other areas in the county only got slightly over an inch the night the two communities got a lot of rain,” said Woods Houghton, Eddy County Extension Service agriculture agent.

Houghton said the rain in Loving and Malaga resulted in heavy damage to crops and farmland, while agriculture producers in other parts of the county continue to struggle with drought conditions.

Sens. Jeff Bingaman and Tom Udall, D-N.M., this week urged Agriculture Secretary Tom Vilsack to quickly approve New Mexico’s request for a natural disaster declaration for seven counties including Eddy County suffering from severe drought and high winds.

Farmers south of Carlsbad are in a difficult situation. They need to cut their alfalfa, but some can’t get into their fields because the soil is muddy and bogs down their machinery. ..“The 6 inches of rain did a lot of damage to the borders in the fields. The heavy rain moved a lot of dirt around. Repairing the borders in the fields is costly.

Schwarzenegger sends aid to drought-stricken areas
The Associated Press Posted: 06/19/2009 05:19:56 PM PDT

SACRAMENTO—Gov. Arnold Schwarzenegger has issued a statewide executive order to send drought-stricken communities money to help fill their food banks.
Schwarzenegger says the state will send between $3 million and $4 million in emergency food and unemployment assistance to local governments and nonprofits.

Also on Friday, the governor petitioned the White House to declare Fresno County a federal disaster area in a bid to get more money. Local officials had requested the petition.

Are “water wars” in our future?

Water is already a subject of contention in the Southwest, and “projected temperature increases, combined with river-flow reductions, will increase the risk of water conflicts between sectors, states, and even nations.”

Some potential conflicts have been many years in the making: “many water settlements between the U.S. Government and Native American tribes have yet to be fully worked out…Competing demands from treaty rights, rapid development, and changes in agriculture in the region, exacerbated by years of drought and climate change, have the potential to spark significant conflict over an already over-allocated and dwindling resource.”

Climate change acts as a threat multiplier for wildfires.

“Wildfires are projected to increase, especially in the Southwest, threatening communities and infrastructure directly and bringing about road and rail closures in affected areas.”

“The frequency of large wildfires and the length of the fire season have increased substantially in recent decades, due primarily to earlier spring snowmelt and higher spring and summer temperatures.”

“Data on wildland fires in the United States show that the number of acres burned per fire has increased since the 1980s.”

How are southwestern states coping and dealing with climate change impacts?

Arizona Highlights:

•  On Sept. 8, 2006, Governor Napolitano signed Executive Order 2006-13, which established a statewide goal to reduce Arizona’s future GHG emissions to the 2000 emissions level by the year 2020, and to 50 percent below the 2000 level by 2040.

• The Climate Change Executive Committee has begun to develop implementation strategies for the recommended policy actions. Four work groups comprised of state agencies named in Executive Order 2006-13 are examining Action Plan recommendations in the following areas:

–  Energy Efficiency and Renewable Energy (EE/RE)
–  Transportation
–  Agriculture and Forestry
–  Biofuels

California Highlights:

• California has been way out in the lead of other states in its approach to climate change; there is too much activity to do it justice in this short summary.  However:

Governor Schwarzenegger and the State Legislature passed the California Global Warming Solutions Act of 2006 (Assembly Bill 32) that caps California’s greenhouse gas emissions at 1990 levels by 2020. By 2050, the Governor has established a goal of reducing emissions to 80 percent below 1990 emission levels in 2050.

•  The Governor established the California Environmental Protection Agency (CalEPA) as the lead for coordinating all state agency actions for reducing greenhouse gas emissions in 2005. A Climate Action Team was established representing representatives from key state agencies responsible for implementing strategies and programs to reduce greenhouse gas emissions.

•  Climate Action Team subgroups made up of agency staff grouped around sectors such as agriculture, forestry and energy have been formed to identify and analyze measures for reducing greenhouse gas emissions. Each Agency and major department is contributing to the development of strategies for both mitigating the impacts of climate change and adapting to the impacts California is already experiencing.

Nevada Highlights:

•  On July 29, 2008, Governor Jim Gibbons received the Final Report from the state’s Climate Change Advisory Committee established in 2007.  It is the culmination of more than a year’s worth of work by the committee, charged with making “recommendations by which greenhouse gas emissions can be further reduced in Nevada, including the use of renewable energy resources.”  They evaluated 63 recommendations before reaching consensus on 28 ideas and prioritizing six of those. The recommendations are grouped into six sections: electricity consumption, residential/commercial/industrial, transportation, waste management, agriculture and “other.”

New Mexico Highlights:

•  “Recognizing the profound implications that global warming and climate variation could have on the economy, environment and quality of life in the Southwest, New Mexico Governor Bill Richardson signed an Executive Order on June 5th, 2005, establishing the New Mexico Climate Change Action Council and the New Mexico Climate Change Advisory Group (CCAG)”

•  The state of Mexico produced a report on impacts in December 2005:  POTENTIAL EFFECTS OF CLIMATE CHANGE ON NEW MEXICO

• On February 28, 2006, New Mexico Governor Bill Richardson and Arizona Governor Janet Napolitano signed an agreement launching the Southwest Climate Change Initiative, which establishes a framework for the two states to collaborate on strategies to address the impacts of climate change in the Southwest and reduce greenhouse gas emissions in the region.

Utah Highlights:

•  Governor Jon Huntsman, Jr. established a Blue Ribbon Advisory Council on Climate Change (BRAC) on August 25, 2006, to provide a forum where government, industry, environment, and community representatives could identify proactive measures that Utah might take to mitigate the impacts of greenhouse gases (GHG); they issued a final report in October 2007.  It focuses exclusively on mitigation options in various economic sectors.

See related posts:

Part 1:  “Global Climate Change Impacts in the US”—Report Overview (Part 1 of a series)

Part 2:  Climate change in our backyards:  the Northeast

Part 3:  Climate change in our backyards:  the Southeast

Part 4:  Climate change impacts in our backyards:  the Midwest

Part 5:  Climate change impacts in our backyards:  the Great Plains


Primary Source:  Global Climate Change Impacts in the United States.  See the full, very-accessibly-written report for a more extensive discussion, including a substantial complement of graphics.

Union of Concerned Scientists (UCS):  Backgrounder on the Southwest

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