The University of Arizona

Category | CLIMAS


Introducing the 2016 CLIMAS Climate and Society Graduate Fellows

Wednesday, January 13, 2016

The Climate & Society Graduate Fellows Program supports University of Arizona graduate students whose work connects climate research and decision making. The program is made possible by support from the Climate Assessment for the Southwest (CLIMAS), the International Research Applications Program (IRAP), and the UA Office for Research and Discovery. Fellows receive $5,000 and guidance from members of the CLIMAS research team for one year. The program’s main objective is to train a group of students to cross the traditional boundaries of academic research into use-inspired science and applied research. While CLIMAS research generally occurs in the Southwest U.S., the Fellows program allows students to work anywhere in the world.

Fellows’ projects may follow two tracks. Students who want to conduct collaborative research may use their funding for use-inspired projects. Students who have conducted climate research and want to communicate their findings to audiences outside of academia may use their funding for outreach. Fellows may also use their funding for a combination of the two tracks.

The Climate & Society Graduate Fellows Program helps students address the world’s climate-related problems by funding projects that engage people outside of the university.

The 2016 Climate Assessment for the Southwest (CLIMAS) Climate & Society Graduate Fellows are:

Saleh Ahmed

Developing a Community Hub for Climate Innovations in  Southwest Coastal Bangladesh

Abstract: Bangladesh ranks as one of the countries most vulnerable to the impacts of climate variability and change. A majority of local farmers and fishermen, whose livelihoods are dependent on climate-sensitive sectors, do not receive adequate climate information that can help improve their adaptation decision-making and increase community resilience. However, several evidence suggest that poor and marginalized farmers can improve their adaptation decision-making if they receive the appropriate demand-driven climate information in a timely manner. This motivates to develop a stakeholder-driven and user-inspired community hub for climate innovations in southwest coastal Bangladesh, where the livelihoods of majority of people are dependent on climate-sensitive sectors, and exposed to various adverse impacts caused by climate variability and change. This community hub should play instrumental role in creating opportunities for multi-way interactions and knowledge and information exchange by coproducing climate knowledge among various stakeholders concerning climate-related issues that are directly linked to local livelihoods. Ultimately, this community hub for climate innovations should play critical role promoting various social innovations in the region. The fundamental objective of this project, with the support from CLIMAS, is to develop a stakeholders-driven & use-inspired process of needs assessment that feeds into a development proposal, which can ultimately be scaled-up by national or international development partners for larger impacts across the regions. A small farming community in southwest coastal Bangladesh is the focus of this planned project.

Schuyler Chew

Collaborative Outreach and Climate Adaptation Planning with the Pyramid Lake Paiute Tribe

Abstract: The Pyramid Lake Paiute Tribe (PLPT) in Nevada is deeply connected physically, culturally and spiritually to Pyramid Lake and has made substantial gains to protect this ecosystem. Through collaborative efforts, our research team has been working with PLPT to understand how climate change might impact tribal water resources. We developed a mass-balance approximation tool to simulate Pyramid Lake elevation over time under various climate change scenarios and proposed ten adaptation recommendations that might enhance tribal adaptive capacity. I seek to build on this research endeavor by discussing with PLPT decision makers how to improve the mass-balance tool’s usefulness for water resource planning. I also plan to collaboratively engage with tribal stakeholders to develop a set of guiding principles that the tribe can use to evaluate climate adaptation strategies.

Stina Janssen

Solar Sovereignty: use-inspired collaborative research for affordable off-grid solar on the Navajo Nation

Abstract: The Navajo Nation is experiencing severe and worsening drought conditions exacerbated by climate change. As a CLIMAS Fellow, Stina Janssen will collaborate with Black Mesa Water Coalition (BMWC) to coproduce research usable for the development of off-grid residential solar systems affordable to low income Navajo households. Stina's research will explore constraints and possibilities for finance and community-ownership or community-control structures applicable for BMWC's solar program. 

Sarah Kelly-Richards

Outreach for Small Hydropower Governance in Chile

Abstract: Globally, renewable energy production is promoted as a mitigation strategy for climate change. Supported by a Fulbright Scholarship in Chile, my dissertation research examines the challenges and potential of small hydropower (typically generating between 1 to 20 megawatts) as form of climate change mitigation. As a CLIMAS fellow, I will conduct outreach informed by research findings that is designed to connect local knowledge of small hydropower development with environmental policymaking. Ultimately, my project seeks to support social justice and environmental sustainability within the transition to renewable energy. 

Joy Liu

Dryland conservation in China: local incentives drive collaborative action on regional climate adaptation

Abstract: This project will assess the local incentives that drive collaborative efforts to conserve dryland systems on agricultural landscape in northern China by collaborating with a non-profit organization (NGO) called Green Action Charity Foundation. The Foundation collaborate with two other stakeholders: County-level officials, and village leaders in Shanxi province to develop tree-planting models, and achieve reforestation targets set by the national government. But NGO efforts face the challenge of integrating conservation, local development needs and regional climate adaptation strategies. Data from interviews and ethnographic study conducted during summer 2014 serve as basis to identify possible incentives and disincentives for collaboration among stakeholders. In summer and fall 2016, a comparative community-level climate adaptation profile and drivers for participation in conservation efforts will be documented and analyzed through stakeholder perspectives in two villages in Shanxi and Gansu province, China. These findings will be used by the Foundation and other stakeholders to develop an updated integrative collaborative model that may help us understand what drives dissonance between values and subsequent collaborative behavior in the context of dryland conservation in China. 

Bhuwan Thapa - CLIMAS Climate & Society Fellow

Tuesday, November 17, 2015

Bhuwan Thapa is a 2015 CLIMAS Climate & Society Graduate Fellow. He and the other graduate fellows (C. Greene, E. Magrane, & V. Rountree) will present the results of their fellowship work on Friday Nov 20, at 10:30 a.m., in ENR2, Room 604.

Figure1: Community members in Tupche VDC, Nuwakot celebrating Rice Plantation Day within two months of the earthquake event (Source: B. Thapa, June 30, 2015)

How farmers are responding to Gorkha Earthquake, climatic and socioeconomic changes in Nepal

Following the Gorkha earthquake in April 2015, many able farmers in the hard-hit Nuwakot district came together and repaired the damaged irrigational canals. They contributed labor and financial resources and where necessary procured additional funding from government institutions. Though some systems could not be repaired immediately due to lack of human and financial resources, the farmers demonstrated the power of collective action in responding to national disasters.

One of the uniqueness of Nepalese irrigation system is the farmer-managed irrigation system where farmers take the responsibility of the overall irrigation management including operation and maintenance. Indeed during the field trip of summer 2015, I learned that these institutions were pivotal in responding to multiple stresses resulting from natural disasters, climatic and socioeconomic changes.

Over the years, stresses on agriculture and water management have materialized in various ways. The monsoon has become erratic causing unpredictable rainfall with variable timing and intensity. The crops are infected with new diseases due to agricultural practices and warmer temperature. The increase in labor price due to massive labor outmigration in Arab countries and high fertilizers price have made some crop varieties economically unviable. These changes have serious implications on irrigated agricultural productivity and wellbeing of thousands of farmers subsiding on agriculture.

In response, the farmers have addressed these challenges through different strategies. In order to supply additional water during shortages, they have installed water pumps to lift river water to up to 50 feet high and distribute through existing irrigation distribution system. In areas where augmenting additional water is not an option, farmers have switched to less water demanding crops. Most of the farmers now use hybrid varieties that produce high yield for less water.

These diverse interventions implemented by farmers have provided me with valuable insights on on-the-ground climate change adaptation.  When provided with right incentives and resources, farmers have demonstrated effective adaptive responses through structural and non-structural interventions. Some of the structural interventions included adoption of technology and hybrid seed varieties whereas non-structural interventions were the modifications of water management rules and changes in agricultural practices based on local knowledge. I have learned that the local level institutions with decentralized decision making can be the platform for adaptive responses. These institutions can be crucial for resiliency of irrigated agriculture because they empower the farmers and strengthen their capacity for timely response during crisis.

I have immensely benefited from knowledge-coproduction model that I applied in this research. I incorporated farmers’ group as the valuable partner with repository of local knowledge on adaptive responses. They shed light on multi-faceted dimensions of climate change and provided feedback on my findings which helped me align my research questions on the areas that are more relevant to them.

The research was conducted during summer of 2015 with support from CLIMAS fellowship and ICIMOD HI-AWARE project. Comprehensive study on climate resilient irrigated agriculture in Gandaki River Basin in Western Nepal will be conducted as a part of my PhD research funded by ICIMOD HI-AWARE project.

Christina Greene - CLIMAS Climate & Society Fellow

Thursday, November 12, 2015

Christina Greene is a 2015 CLIMAS Climate & Society Graduate Fellow.  She and the other graduate fellows (E. Magrane, V. Rountree, & B. Thapa) will present the results of their fellowship work on Friday Nov 20, at 10:30 a.m., in ENR2, Room 604.

Almonds, Fish, and a Modern Dust Bowl: Narratives of Drought Vulnerability and Adaptation in California's San Joaquin Valley

The plums were a deep red, their oozing juices staining the human-sized cardboard box in wine colored hues. Instead of being stacked in neat pyramids or ensconced in plastic, they were piled in by the hundreds, pressing against each other, their bursting flesh perfuming the air. We stood in two single file lines. At the front of the line, volunteers grabbed plums by the handful and thrust them into our outstretched white plastic bags, counting them out “dos, cuatro, ocho, doce, veinte!” I asked the gentleman in front of me in the line “What are plums called in Spanish?” He smiles at me from beneath his cowboy hat, “Ciruela.”

After all the plums have been bagged, we begin the process again with pallets of tomatoes, frozen chickens, rice, beans, and cucumbers. When all the food is packed and sorted into piles, we distribute them to the residents of this small rural city in California’s San Joaquin Valley where everyone’s job depends on agriculture.  Throughout the day I ask people about California’s drought – la sequía. They nod gravely, yes – la sequía.

“We have less hours in the field this year.”

“The harvest season is shorter by a few weeks.”

“My water bill is very high. So much money!”

“There are fewer hours at the packing plant – I am thinking of moving and joining a cousin in Chicago.”

For my CLIMAS fellowship I am researching the impacts of the California drought on the rural agricultural communities of the San Joaquin Valley. As agriculture is the major source of livelihood in these communities, there is great concern that the drought is impacting farmworker jobs and their ability to put food on the table. In response to the drought, the State of California allocated $25 million in drought relief food boxes to be distributed in communities with high numbers of farmworkers. By volunteering at food aid distributions and speaking with farmworkers, farmers, labor contractors, city officials, social service providers, and state government officials I am researching drought vulnerability.

Droughts occur when there is not enough water to meet the demands of a society or an environment. As droughts are both a physical and a social event, it is important to understand the human dimensions of drought – who is most impacted by the drought and what environmental, economic, and social factors are shaping drought vulnerability? In climate research, there are many different ways to define vulnerability. The IPCC defines vulnerability as the “The propensity or predisposition to be adversely affected” (IPCC, 2014).

To understand drought vulnerability in California, I am asking who is being impacted that is unable to cope and adapt to these impacts? How are they being impacted and how do factors such as the labor market, crop choices by farmers, social services, and migration shape drought vulnerability?

As debates in the media surge around how many gallons of water it takes to produce one almond or what percentage of water does agriculture consume, it is important to also examine the drought’s impacts on jobs and access to food and water for people living and working in the region that produces the majority of the country’s fruits and vegetables.


  • IPCC (2014) Climate Change 2014: Impacts, Adaptation, and Vulnerability. Part A: Global and Sectoral Aspects. Contribution of Working Group II to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, UK and New York, USA.

Preparing for High Consequence, Low Probability Events: Heat Water & Energy in the Southwest

Tuesday, November 10, 2015

Residents of the Intermountain Southwest are accustomed to hot temperatures. More than 90 percent of households in Arizona use air conditioning, which accounts for a quarter of the energy consumed in homes: more than four times the national average (U.S. Energy Information Administration).

Now imagine a scenario: It’s June, temperatures are normally over 100 degrees F, but a persistent heat wave causes temperatures to soar over 120 degrees F for several days in a row, with nighttime low temperatures at or near 100°F. Everyone is using their A/C, which overloads the system and results in an extended power outage. Now, not only is it scorching, but without power residents have no way to cool off in their homes. What’s more, the lack of power knocks out the wastewater treatment plant, and now residents lack potable water as well.

You may be thinking that this scenario is highly unlikely, and you’re right. But what if? What if over three million people in the Phoenix metro area lost power during a desiccating pre-monsoon heat wave? Or, what if this situation occurred in Las Vegas, where, in addition to a million residents, there are tourists who are unaccustomed to the heat? How do we plan for something like this? How do we manage the cascade of impacts?

These are the types of questions and scenarios discussed at a workshop, entitled “Preparing for High Consequence, Low Probability Events: Heat, Water & Energy in the Southwest,” held in September in the University of Arizona’s new ENR2 building, in Tucson. The heat-related theme was apt, as temperatures outside topped 100°F. The workshop, funded by the U.S. Bureau of Reclamation, brought together over 30 practitioners in water, energy, and emergency management with researchers, in order to improve connections across these sectors, while increasing knowledge about intersecting risks and research and management needs related to the heat-water-energy nexus in the Southwest U.S.

Talks by prestigious scientists and practitioners set the stage for lively discussions and working sessions. Among the talks were two case studies of cascading impact events in the recent past:

  • Daryl Slusher (Austin Water Utility, Assistant Director) described how drought in Texas in 2011 and 2012 drastically reduced water levels in many reservoirs, including the sole water supply for the City of Austin, leading to unprecedented water restrictions and power outages in some areas; and
  • Ronald Lane, (San Diego County, Deputy Chief Administrative Officer) discussed a 2011 power outage in San Diego that led to a cascade of impacts, including airport and school closures, transportation disruptions—because the power outage rendered gas station fuel pumps inoperable, and a major sewage spill due to the shutdown of a water and sewage pumping.

Participants, some of whom have managed weather-related crises, generated useful insights into planning and managing rare, but impact-filled cascades of events. One key insight was the need for using “possibilistic” as opposed to “probabilistic” thinking to improve communication with local communities; knowing about what is likely to happen (probabilistic) is useful, but in practice it does not lead to the type of preparation needed for rare, but potentially debilitating events. Some key discussions focused on:

  1. What does it take for organizations to learn after disasters? Critical lessons learned during crises are often forgotten, unless institutional mechanisms are in place to capture them. It took a second severe drought in less than a decade for Colorado to set up institutions to tackle simultaneous intersecting impacts (e.g., low water supply and multiple fire outbreaks), through routine pre-crisis planning and preparedness for multiple impacts. In contrast, earthquake-prone Los Angeles successfully mobilized public funding to reduce risks from future quakes by learning from an earlier Mexico City earthquake.
  2. As long-term temperature and precipitation trends increase the likelihood of acute high-impact events, what changes in planning are required to develop effective interventions? There are clear lines of responsibility for acute events, such as severe storms or floods, but no single lead agency is in charge of the added risk from long-term trends. This is an important direction in which researchers and practitioners can work together to reduce societal risk, even as exposure to risk (e.g., heat waves, lower water supply reliability, etc.) increases.
  3. How can we best coordinate multiple levels of disaster planning and response, in anticipation of high-impact, low probability events? While state and national-level coordination is essential, citizen- and neighborhood-level monitoring, knowledge, and social networks play key roles – but too little is known about those networks, their intrinsic preparedness and adaptability. 'Possibilistic' thinking across all of these levels of decision making and coordination is needed to maximize preparedness, reduce risk, and reduce the costs associated with disasters.

Workshop organizers will produce a workshop report by the end of November. In the meantime, a workshop agenda and PDFs of presentations can be found here.

CLIMAS Colloquium: Connie Woodhouse - Collaborative Research in the Upper Colorado River Basin: User-Driven Research Results and Challenges

Thursday, March 26, 2015

This presentation will focus on ongoing work to better understand the effects of temperature on water supplies in the upper Colorado River basin. Overall, spring and early summer temperatures explain only a small portion of the variance in water year streamflow in the basin. However, in a subset of years (both warm and cool), temperatures appear to have a stronger influence on streamflow than might be anticipated, given the precipitation. The presentation will also touch on the challenges associated with incorporating the input of water resource management partners, a central component of the project design.

Connie Woodhouse's research concerns the climatology of western North America, including paleoclimatic reconstructions of past climate and hydrologic conditions from tree rings, the analysis of past and current climate, and circulation features that influence climate, particularly at decadal and longer time scales. Her work has ranged from the reconstruction and analysis of drought in the western Great Plain, to temperature variability over the past eight centuries in western North America, to the development of a network of streamflow reconstructions for major rivers in the Colorado, Platte, and Rio Grande river basins. A recent emphasis has been on applied research to assist water resource managers in using reconstructions of past hydroclimatic variability in drought planning and water resource management.

WEBINAR: We've arranged to share tomorrow's presentation through GoToMeeting
Registration URL:
Webinar ID: 149-958-747

2015 CLIMAS Climate & Society Graduate Fellows

Friday, March 13, 2015

The Climate & Society Graduate Fellows Program supports University of Arizona graduate students whose work connects climate research and decision making. Fellows receive $5,000 and guidance from members of the CLIMAS research team (Climate Assessment for the Southwest) for one year. The program’s main objective is to train a group of students to cross the traditional boundaries of academic research into use-inspired science and applied research. While CLIMAS research generally occurs in the Southwest U.S., the Fellows program allows students to work anywhere in the world.

Fellows’ projects may follow two tracks. Students who want to conduct collaborative research may use their funding for use-inspired projects. Students who have conducted climate research and want to communicate their findings to audiences outside of academia may use their funding for outreach. Fellows may also use their funding for a combination of the two tracks.

The Climate & Society Graduate Fellows Program helps students address the world’s climate-related problems by funding projects that engage people outside of the university.

The 2015 Climate Assessment for the Southwest (CLIMAS) Climate & Society Graduate Fellows are:

Christina Greene

Abstract: A history of prolonged droughts has long challenged the food system in the Southwest, and these challenges will become steeper under a future of climate change. This project seeks to better understand the vulnerability of the food system to drought by focusing on the impacts of the California drought on farmworkers. By identifying the needs of farmworkers during drought and evaluating the distribution of drought relief boxes through community food banks, this research seeks to connect the environmental and social dimensions of drought, labor, and food insecurity.

Eric Magrane

Abstract: As a CLIMAS fellow, Eric Magrane will design and teach a community course for the University of Arizona Poetry Center called “Climate Change and Poetry.” Climate change is both a scientific and a social issue. It is a threat to life on Earth as we know it as well as an opportunity for social change and environmental justice. A growing body of poetry addresses climate change, and this course will use poems as boundary objects to both communicate climate change and to examine its different frames or narratives. It will explore what role the imaginative and emotional resonances of poetry might have in the way we think about adaptation and mitigation. 

Valerie Rountree

Abstract: In March 2015, the City of Tucson Office of the Mayor will hold a half-day summit on Energy and the Economy with policy makers and business owners in Tucson to discuss the economic opportunities associated with increasing energy and the use of renewable energy. The purpose of Valerie’s CLIMAS project is to enhance the summit and evaluate its success in engaging participants and initiating action on energy efficiency and renewable energy in the private sector.  The project will include three parts: first, a pre-summit survey of prospective attendees will be administered to get baseline data regarding participants’ opinions and knowledge of energy efficiency.  The results of the survey will also be used to tailor the content of the summit to participants’ interests.  Second, a post-summit survey of attendees will be administered to evaluate the impacts of the summit on attendee opinions, knowledge and perceptions.  And third, follow-up interviews will complement surveys to evaluate whether participants plan to implement energy efficiency measures.  The results of this project will be used by partners in the Mayor’s Office to enhance the 2015 Summit and improve summits in future years.

Bhuwan Thapa

Abstract: Nepal’s water resources and agriculture sectors are one of hard hit sectors by climate variability and change. There are about 25,000 irrigation Systems which are managed by farmers and which irrigate about 25 percent of total irrigated area in Nepal. Though Farmer-managed irrigation system (FMIS) is considered a robust system, it is facing increasing stresses from climatic and non-climatic elements including competing water demands, frequent infrastructure damage from flooding and landslides, degraded water quality, and poor governance. My study will conduct use-inspired research on adaptation strategies of FMIS in order to strengthen their management capacity. As a part of the project, I will conduct i) participatory assessment of biophysical and social vulnerabilities of the FMIS to climatic stresses; and ii) support the irrigation managers with development of appropriate adaptation strategies.

Notes From the Field: Preparing for Climate Change Along the US-Mexico Border

Monday, October 27, 2014


On September 10-11, 25 scientists and natural resource managers met at the offices of the International Boundary and Water Commission (IBWC), in El Paso, Texas.  Their goal was to use strategic scenario planning techniques to gain insight into environmental and natural resource planning under highly uncertain conditions. Participants included climatologists, meteorologists, geologists, hydrologists, ecologists, biologists, and environmental economists, representing a range of U.S. and Mexican federal agencies, state agencies, universities, and non-governmental organizations.

The workshop was organized by an ad hoc consortium of partners that consisted of:

The workshop focused on riparian zones and adjacent ecosystems in the Big Bend reach of the river, including the Rio Grande Wild and Scenic River, and the Monumento Natural Río Bravo del Norte en Mexico. During the two-day workshop, participants were briefed on the climate, hydrology, and ecology of the region.

Workshop Goals

  • Introduce participants to scenario planning methods for dealing with situations of high uncertainty—especially with respect to climate—and making use of climate information in decision making
  • Foster a spirit of collaboration and build bilateral teams for ongoing planning,
  • Exchange knowledge with regional risk managers about decision making needs, climate forecasts and projections, decision contexts, constraints, and risk tolerance,
  • Increase awareness of regional efforts, in order to identify areas of mutual interest and facilitate coordination and collaboration.

Dr. Holly Hartmann (Holly C. Hartmann Consulting)introduced workshop participants to strategic scenario planning techniques used by industry, the military, and some federal agencies, and facilitated most of the scenario planning exercises [2].  These techniques are focused on addressing factors outside the control of resource managers, such as climate or economic fluctuations, and were designed to help managers make informed decisisons despite considerable uncertainty.

NOAA scientists from the National Climatic Data Center, NOAA’s Southern Region office, and the El Paso Weather Forecast Office, worked with regional and state climatologists, including CLIMAS’s Dave Dubois (New Mexico State University), to assess plausible future conditions despite highly variable climate factors, including summer precipitation totals and the date of onset for the North American Monsoon (NAM). Texas State Climatologist, John Nielsen-Gammon (also an affiliate of the SCIPP RISA), laid out key facts about the regional climate:

  • The region receives the vast majority of its annual precipitation during the summer season,
  • Regional precipitation variability is exceptionally high, and
  • Aside from temperature-related soil moisture decreases, there is very high uncertainty associated with climate model projections of future precipitation.

During wide-ranging discussions about the uncertainty of future climate conditions, we considered possible eastward and westward shifts in the center of action of the NAM in the border region, the timing, intensity, and amount of summer precipitation, the severity and extent of regional drought, and the impact that these factors might have on river hydrology, especially sediment flows [3].

What We Accomplished

Participants developed four preliminary scenarios focusing on:

  • Uncertainty regarding the amount and timing of future precipitation;
  • How future cooperation between stakeholders amplifies or moderates future environmental challenges; and
  • The degree to which implementation of management actions is based on correct scientific understanding of future environmental changes.

Discussion amongst participants revealed a need for more cross-border collaboration to increase preparedness and coordination, and to achieve positive outcomes in the face of future climate conditions such as sustained drought or increased flash flood frequency.

Toward the end of the workshop, IBWC Commissioner Edward Drusina, took time from his busy schedule to address the participants. He emphasized the need to build capacity, on both sides of the international border, for timely and informed responses to the challenge of drought and extreme climate variations. He urged participants to make it a priority to communicate their knowledge to society.

Key outcomes of the workshop:

  • Increased capacity in the Rio Grande-Río Bravo bi-national region for using scenario planning to address uncertainty in future climatic conditions;
  • Preliminary climate change scenarios for the region, including plausible scenarios of future environmental and social impacts; and
  • Enthusiasm for continued and more detailed and deliberate bi-national discussions of these issues.

Next steps in this process:

  • Expand scenario planning methods to a broader stakeholder group interested in the region, and
  • Continue the scenario planning process by exploring existing and alternative scenarios in greater depth, and developing a portfolio of potential adaptation actions and strategies.

These steps will engage additional participants using workshops in Mexico and the U.S.

The Desert LCC is also looking to apply the climate scenario methodology presented at this workshop to landscape conservation planning and design.

Acknowledgment: This blog post benefited greatly from input by the workshop organizing committee, mentioned above


  1. About the North American Climate Services Partnership (NACSP) - In 2012, the weather services of Canada, the United States (NOAA), and Mexico signed a statement of intent to facilitate the exchange of information, technology and management practices related to the development and delivery of climate and water information for North America. The goals of NACSP are similar to those of CLIMAS: to foster the development of partnerships with the users of climate information, to enhance and improve the use of climate information by decision makers, and to create opportunities to share lessons learned from pilot projects and research. In 2013, yours truly was designated the co-chair of the Rio Grande/Rio Bravo pilot project. More information about the NACSP.
  2. Hartmann's ongoing work on scenario planning and decision support has been pivotal for land management agencies such as the National Park Service and the Bureau of Land Management.
  3. During the last 50 or more years, sediments have been accumulating in the Big Bend reach of the Rio Grande; this has caused a degradation of habitat for fish species and other animals and plants.

Image Credit:

  1. Figure 1: US/Mexico Region - Source: Mark Briggs - World Wildlife Fund
  2. Figure 2: Big Bend National Park & Rio Grande Wild and Scenic River - Source: Billie Brauch vs. Jeffery Bennett - National Park Service - US Dept of the Interior.

Climate Change Scenario Planning in Central New Mexico

Monday, July 7, 2014

Reporting on Future Regional Climate and Related Impacts for the Central New Mexico Climate Change Scenario Planning Project

Similar to many other metropolitan areas in the western United States, Albuquerque and surrounding cities in central New Mexico comprise a rapidly growing region in an arid environment. Planning for such an area in the 21st century requires addressing a mixture of challenges from congestion, sprawl, energy use, vehicle emissions, water supply, and potential changes in future regional climate along with related impacts.

Led by the U.S. Department of Transportation’s John A. Volpe National Transportation Systems Center, a group of federal agencies and the Mid-Region Council of Governments of New Mexico is embarking on a project – the Central New Mexico Climate Change Scenario Planning Project – to help the region address these intertwined challenges. This project aims to influence regional transportation and land-use decision making, and analyze strategies to reduce carbon emissions and prepare for impacts related to potential changes in future climate.

To support these efforts, a new CLIMAS report provides a summary of current research on anticipated changes to temperature and precipitation in the Southwest – with particular attention to central New Mexico and the upper Rio Grande basin – over the course of this century, as well as some of the potential impacts related to these changes. Along with information regarding the magnitude and direction of such changes, this report also presents the level of confidence that experts have in such changes, which is an important aspect of interpreting climate projections.

Farm and Ranch Weather and Climate Workshop

Thursday, June 5, 2014

University of Arizona Cooperative Extension and the National Weather Service – Tucson Forecast office are sponsoring a morning long training workshop on weather and climate information focused on supporting agricultural and resource management decision- making. Topics will include:

  • Finding and interpreting NOAA-NWS weather monitoring and forecast products
  • An overview of the UofA Arizona Meteorological Network and crop and irrigation management products
  • A discussion of drought monitoring efforts including an overview of the U.S. Drought Monitor
  • El Niño and an update of seasonal forecasts through winter of 2014/15

The workshop will end with an informal discussion of information needs and opportunities for further product and service development to support southeast Arizona. Lunch will be provided.

June 12, 2014 – 8:30 -12pm - (Check-in begins at 8am)

Willcox Community Center – Fireplace Room

312 W Stewart Street, Willcox

Please register for the workshop by June 6th by calling 520-384-3594 or by emailing Connie at

Workshop Materials / Key Web Links

Contact Mike Crimmins with questions/comments about the materials/workshop

Video: UA experts discuss Climate Change Impacts, Adaptation and Vulnerability

Tuesday, April 1, 2014

CLIMAS and the Center for Climate Adaptation Science and Solutions co-sponsored a panel of UA experts to discuss the recent report from the Intergovernmental Panel on Climate Change (IPCC) entitled "Impacts, Adaptation, and Vulnerability." This report, from the IPCC's Working Group II (WGII), provides an assessment of the scientific, technical, environmental, economic and social aspects of climate change vulnerability for and impact on ecological systems, socio-economic sectors and human health, with an emphasis on regional, sectoral and cross-sectoral issues.

IPCC Panel Discussion March 31 2014 from Environment UA on Vimeo.

UA experts discuss the IPCC WGII Report: Climate Change Impacts, Adaptation and Vulnerability

Monday, March 31, 2014

A video recording of this IPCC panel discussion is now available on the CLIMAS media page.

Monday, March 31, 2014
11:00 a.m. - 12:30 p.m.
UA Student Union, Kiva Room

CLIMAS and the Center for Climate Adaptation Science and Solutions are co-sponsoring a panel of UA experts to discuss the forthcoming report from the Intergovernmental Panel on Climate Change (IPCC) entitled "Impacts, Adaptation, and Vulnerability." This report, from the IPCC's Working Group II (WGII), provides an assessment of the scientific, technical, environmental, economic and social aspects of climate change vulnerability for and impact on ecological systems, socio-economic sectors and human health, with an emphasis on regional, sectoral and cross-sectoral issues.

A panel of UA experts will discuss the report and field questions. We encourage interested members of the public, the university community, and the press to attend.

The WGII Report's Summary for Policymakers is scheduled to be released just prior to the event and will be available at:

The panelists are as follows:

Jonathan Overpeck, co-director of the UA Institute of the Environment and a lead author on the IPCC WGII chapter on terrestrial and inland water systems, will provide a short overview of the Summary for Policymakers. Overpeck has published more than 160 papers in climate and the environmental sciences and served as a coordinating lead author for the Nobel Prize-winning UN Intergovernmental Panel on Climate Change (IPCC) Fourth Assessment (2007).

Kathy Jacobs, director of the UA Center for Climate Adaptation Science and Solutions, will speak on some of the climate adaptation activities detailed in the forthcoming IPCC report with a particular focus on North America. Jacobs is a nationally recognized water, climate and adaptation expert who recently returned to the UA from Washington, D.C., where she spent the past four years as assistant director in the Office of Science and Technology Policy in the White House. There she was the lead advisor on climate adaptation and water issues and director of the Third National Climate Assessment.

Christopher Scott, an associate professor in the UA Udall Center for Studies in Public Policy and the School of Geography and Development, will discuss adaptation and decision making in the context of water resource issues in the Southwest and across the globe. His research and stakeholder engagement work addresses water resources and policy, human-environment interactions, the water-energy nexus, and climate adaptation.  His applied research emphasizes the importance of science-policy dialogues with particular attention to ecosystem services, groundwater depletion, water reuse, and transboundary adaptive management.

David Breshears, a professor in the UA School of Natural Resources and the Environment, will discuss climate change impacts on ecological systems. His research focuses on interactions among woody and herbaceous plants in the context of the grassland/forest continuum, ecological and hydrological interrelationships, impacts of drought and fire, water and wind erosion, and more recently, biophysical scaling relationships and new technology for measuring soil carbon. His research has been applied to a diverse set of assessments in areas including contaminant-related risks, land management, and global change.

Diana Liverman, co-director of the UA Institute of the Environment, will discuss impacts on, and vulnerability of, food systems, human security, key economic sectors, and other cross-sectoral issues. Her research focuses on the human and social dimensions of environmental issues including vulnerability and adaptation to climate change, environmental change and food security, and international climate and environmental policy. She has authored or edited seven books, more than 100 journal articles and book chapters and has supervised more than 60 graduate students.

Climate & Health Workshop

Friday, February 14, 2014

This workshop is open to UA researchers engaged in research around climate and health. The workshop will aim to stimulate research on the climate and health nexus, to learn about research in this area occurring on our campus, and especially, to see if substantial interest exists in pursuing collaborative grants.

A light breakfast will be provided.

8:30-8:45 a.m.—Introduction—Margaret Wilder & Heidi Brown, Co-PIs, CLIMAS
8:45-9:15 a.m.—Climate-Health Research at the UA: Setting the Context—Provost Andrew Comrie (Co-PI, CLIMAS)
9:15-10:15 a.m.—Discussion about advancing climate-health research at the UA
10:15-10:30 a.m.—Next steps – discussion of future workshop and proposals
10:30 a.m.—Adjournment

The meeting will feature a keynote address by Provost Andrew Comrie, CLIMAS co-PI and Professor in the School of Geography and Development, whose research examines the links between climate and mosquito-borne disease in the Southwest. Following the Provost’s presentation, we will then have a discussion about climate and health research at the University of Arizona, to gauge interest in developing ideas for larger collaborative research proposals. The workshop’s outcome will be a concrete framework to carry out these proposals moving forward. We believe that a number of undeveloped synergies exist on campus that could bloom into a productive research cluster around climate and health in the future. Please see included agenda.

Please respond to Emma Lawlor at by Monday, February 10, to RSVP for the workshop.

Roundtable Discussion with Professor Hari Osofsky

Friday, February 7, 2014

Professor Hari Osofsky, visiting from the University of Minnesota Law School, will give a brief presentation about her work on the dynamics of local networks in climate change policy. Her talk will be followed by a moderated discussion about climate change governance at the regional level. 

Space is limited, so please RSVP to Ryan Thomas <> by noon on Thursday, February 6, 2014.

About Prof. Osofsky:
Professor Osofsky's interdisciplinary law and geography scholarship focuses on governance and justice concerns related to energy and climate change. She collaborates with local, state and county governments on climate change policy in the Twin Cities and Hennepin County, researching methods of overcoming jurisdictional boundaries in climate policymaking.

CLIMAS Colloquium: Megadrought Risk - From the Globe Down to the Southwest

Friday, January 24, 2014

CLIMAS Colloquium Series
Speaker: Jonathan Overpeck

Increased drought risk is (and will be) arguably one of the most certain and troubling aspects of anthropogenic climate change for many parts of the world. At the same time, it is emerging in the scientific literature that state-of-the-art climate and Earth system models are not able to simulate the full range of drought, whether decade-scale droughts like seen recently in both the SW US, and Australia, or multidecadal “megadroughts” that eclipse droughts of the instrumental era in both duration and severity. Evidence for this assertion will be examined, particularly as it comes from the paleoclimatic record of several continents, in both semi-arid and wetter regions. The implications for decision-making will also be discussed, including the on-going operational use, in the United States, of no-regrets drought planning strategies that incorporate paleoclimatic data. Fortunately, because droughts will still occur for natural reasons as well as anthropogenic, increased drought preparedness is a clear “no-regrets” climate change adaptation strategy.

CLIMAS Colloquium: A Southwest Perspective on Climate Change and Health

Friday, November 22, 2013

While there are generalizations that can be made about the effect climate change will have on health, these effects will vary by community.  This talk focuses on the Southwest and some of the health concerns that communities here may face, what actions are being done and what can be done. Brown will delve into the complexity that is climate change and health by focusing on an effort to predict future mosquito borne disease burden. Using a dynamic simulation model, she was able to estimate the number of West Nile virus vectors at different locations across the US under future climate scenarios. Her findings highlight the importance of local action as the changes in vector abundance are not consistent across locations.

November CLIMAS Colloquium: A Southwest perspective on climate change and health

Presenter: Heidi Brown, Ph.D., M.P.H,

Title: “A Southwest Perspective on Climate Change and Health”

Regional Climate Summit for Municipal Leaders: Economic, Health, Water & Transportation Impacts

Thursday, November 14, 2013

Workshop report now available: Planning for Change in Southern Arizona

Update: Thanks to everyone who attended this event and helped make this a successful workshop. Click on the Agenda link to the left to browse the workshop agenda, speaker bios, and to download PDFs of the presentations from this workshop.

Decision makers in southern Arizona face new challenges as climate variability and weather extremes increasingly affect the region. Our municipalities undertake planning activities and public investments that shape our economic prosperity, public health, and environment. Extreme events, warmer temperatures, and changes in precipitation will dramatically impact these efforts.   This half-day summit will explore the risks, potential costs, and proactive solutions necessary to combat and cope with climate change challenges affecting southern Arizona. Participants will learn from other municipal leaders and technical experts. The summit begins a dynamic regional dialogue to leverage ongoing and future efforts in cross-jurisdictional climate-related challenges.

Summit topics include:

  • Economic challenges and opportunities
  • Water, health, and energy in a changing climate
  • Public opinions about climate change

Advancing Climate Adaptation and Resliency Planning in Flagstaff

Thursday, October 24, 2013

The Flagstaff City Manager’s office in collaboration with CLIMAS at the University of Arizona and the Decision Center for a Desert City at Arizona State University will lead a workshop with the Police Department and the Streets section of the Public Works Department to develop performance measure for climate adaptation that these departments can use in future budget preparations and strategic planning.  The workshop will build on Flagstaff’s Resiliency and Preparedness Study (RPS) and the policies adopted by the Flagstaff City Council. The workshop will be divided into two parts. The first section will include expert presentations on topics that will inform the second Part.  After part 1, participants for police and public works departments will be split up and lead through a series of progressive discussions that aim to:

  • Identify climate risks pertaining to the department
  • Identify short and long-term strategies to deal with those risks
  • Develop planning/implementing actions related to the viable strategies
  • Identify ways to measure the success of the actions
  • Identify viable performance measures of the actions

The discussion sessions will focus on vulnerabilities and risks identified in the RPS and that fall under the purview of Police and Public Works. These include emergency services, forest management, public health, transportation infrastructure, and storm water infrastructure. 

The goal of the workshop will be for participants to develop climate adaptation performance measures in their respective departments.  While this effort is not meant to be comprehensive, the intent is to identify viable climate adaptation actions that can be evaluated for each of the departments and demonstrate a method for doing so that can be applied to other departments within the Flagstaff City Manager’s office. 

Key Findings from the Assessment of Climate Change in the Southwest

Friday, February 8, 2013

The Southwest is one of the most sensitive regions to climate change in the U.S., and a soon-to-be-released synthesis report will provide the most comprehensive update on the state-of-the-science on climate changes and impacts for Arizona, California, Colorado, Nevada, New Mexico, and Utah. The report, “The Assessment of Climate Change in the Southwest United States,” documents that the Southwest will likely experience continued temperature increases, summer heat waves longer and hotter than experienced in the past, and reduced streamflows, among other climate and ecosystem changes. The report also highlights potential critical changes in key sectors. Agriculture, for example, will likely experience fewer chill-hours, which may force-out some fruit tree producers. Energy production may become less reliable due to potential climate-related increases in demand and declines in power generation efficiency due to increased heat and decreased water supplies. And public health may experience increases in human morbidity and mortality due to increased heat.
Gregg Garfin, lead-coordinating author of this report, will present these and other key findings on Friday, Jan. 25th at 10:30 am in Marshall 531. The report drew on contributions from 121 authors and will be published in early 2013. You can currently access the first chapter of the report, known as the Summary for Decision Makers. The full report will be available here.

The Assessment of Climate Change in the Southwest United States is one of eight regional technical contributions to the National Climate Assessment, which will summarize key findings from each region and will help inform informs the nation about observed changes and anticipated climate trends.  The National Climate Assessment report will be published later this year.

National Climate Assessment Regional Town Hall

Friday, January 18, 2013

This day-long town hall meeting will bring together approximately 90 people, including climate experts and users of climate information from academia, local, state, tribal, and federal governments, non-profit organizations, businesses, and industry. This event is by invitation only.  Participants will have the opportunity to:

  • learn about the National Climate Assessment and the process leading to the 2013 National Climate Assessment Report (a draft of the report will be available for public comment at the time of the meeting);
  • talk with report authors, members of the National Climate Assessment and Development Advisory Committee, and National Climate Assessment staff about how the information provided in National Climate Assessment products is and can be used in various decision making contexts;
  • learn about local and regional efforts to respond to the impacts of climate change in the Southwest U.S.; and
  • collaborate with other meeting participants to identify ways that you and your community can participate in the long-term National Climate Assessment process.

The town hall will consist of both plenary panels and small group discussions. During the plenary session, National Climate Assessment authors and staff will provide an overview of the National Climate Assessment process, present preliminary findings from the Draft 2013 National Climate Assessment Report, and explain how members of the public may comment on the Draft Report. Additional speakers will highlight local and regional efforts to assess and respond to the challenges of climate change, and will explore the ways in which efforts in the Southwest U.S. are linked to the National Climate Assessment. During the small group discussion time, you will have an opportunity share your own expertise and insights related to climate, assessments, and decision making in the context of climate change, and to suggest and plan pathways to build sustained assessment capacity in the Southwest U.S.

Invasive Species

Monday, September 15, 2008

Many types of invasive plant and animal species have expanded and will continue to expand into new habitats in the Southwest. An invasive species is a plant, animal, or microbe that adversely affects the native ecosystem upon introduction to a new community. Invasive species are well-adapted to encroach upon new territory, and invaders compete with native species for resources like water and soil nutrients. Many invasive species are so well-adapted to diverse conditions that they can outcompete their native counterparts, leading to environmental damage and decreased biodiversity. Regional impacts of climate change, including warmer temperatures, decreased precipitation, and increased levels of carbon dioxide will affect how and where invasive species migrate and colonize.

Figure 1. A large stand of buffelgrass just west of Soldier Canyon.
| Enlarge This Figure |
Credit: Aaryn Olsson, Arizona Remote Sensing Center, The University of Arizona

Invasive species may benefit from climate change because of their ability to adapt. Temperatures and increased carbon dioxide levels in the Southwest may help some invasive species expand into new areas, requiring action from land managers, farmers, ranchers, and those involved in outdoor recreation. Some of these actions include prevention, monitoring, and eradication. Invasive species control requires understanding:

  • How invasive species migrate and colonize
  • Observed impacts of invasive species
  • Climate change implications for invasive species

Migration and colonization

Carriers, most often humans, bring invasive species into a new area, either accidentally (through ship cargo, seed stock, livestock, or travelers) or purposefully (for food, fuel, forage, logging, biological control, recreation, or medicinal uses). Not all species introduced to an ecosystem will survive. Only 10 percent of non-native plant species are estimated to give rise to a steady population because they need the right germinating conditions, like soil type and climate.1 Colonization also depends on how many individual seeds or animals survive the transportation process. Plants with a wide geographic distribution, for example, will do better because they are more tolerant of climate and soil variations.

Certain traits enable plants to establish themselves and outcompete others for resources. These include fast-growth, a short juvenile period, bigger leaf size, and taller stem height than other plants. Invasive species tend to do well in ecosystems disturbed by natural causes, such as fires, or areas damaged by human activity, such as logging, ranching, farming, and urban expansion.

Observed invasive species impacts

The Southwest suffers from many types of invasive species outbreaks, including plants (like buffelgrass, cheatgrass, saltcedar, and red brome), animals (like bullfrogs, cowbirds, quagga mussels, and crayfish), and diseases (such as West Nile virus, rabies, and dengue fever). Invasive plants can alter the landscape by overtaking native species, facilitating fire outbreaks, and altering the food supply for herbivorous animals and insects. Buffelgrass was introduced to the region for cattle feed in the mid-1900s, but has since traveled from ranchlands into the desert ecosystem. Subsequently, these grasses have increased fuel loads in the Sonoran Desert, a region where native plants are not adapted to frequent fires. Buffelgrass-induced fires tend to be faster, longer-lasting, and hotter, and cause more plant and animal deaths than fires involving only native plants.2 After a fire, buffelgrass seeds sprout quickly, often within a few days, while many native desert plants, like saguaro cactus or palo verde trees, take months to years to re-establish themselves.

Figure 2. The known extent of salt cedar invasion in the U.S. The vertical line marks the 100th meridian, west of which rainfall drops below 45 cm yr−1 and agriculture becomes highly dependent on irrigation.
| Enlarge This Figure |
Credit: Allen Press Publishing Services

Invasive species also cause economic losses. Salt cedar, introduced in the mid-1900s to combat soil and wind erosion, has now spread to nearly all perennial drainage systems in the western arid and semi-arid U.S (see Figure 2). Research by Erika Zavaleta shows that saltcedar stands on average consume 3,000 to 4,600 m3 per hectare per year more water than regional native vegetation, leaving less available water for native plants and human consumption. In total, saltcedar in the western U.S. annually costs between $133 to 285 million in lost ecosystem services, such as irrigation water, municipal water, hydropower, and flood control.3

Management for invasive species includes using pesticides or herbicides, labor-intensive species removal, and restoration of native vegetation. Removing invasive species from agricultural or ranchlands, national and state parks, and urban landscapes requires time and money. But if uncontrolled, invaders will overtake these lands, often causing irreversible ecological damage.

Climate change implications

Currently, there is little scientific consensus on the precise impacts of climate change on invasive species, but many hypotheses exist regarding changes to dispersal and introduction patterns, colonization patterns, distribution and establishment patterns, and landscape and management practices.

As land conditions change due to climate variations, invasive species may be able to colonize new geographic areas. Climate change may allow for new travel pathways between previously separate geographic areas, increasing the potential for species interchange. Extreme weather or altered atmospheric circulation patterns could also increase dispersal to new geographical areas.4 Native species that are unable to adapt to changing conditions may die off, opening up resources for non-native plants and animals. Invasive species are more likely to have traits that help them tolerate or adapt to change, such as short juvenile periods or creative dispersal methods, and outcompete native species for soil, water, and nutrients.

As temperatures rise, landscapes currently protected against invasives by cold temperatures could become targets for invading species. Changing precipitation patterns may also allow invasive species to colonize new areas. Increased rain could allow expansion into new regions, while decreased rain could cause invasive species to die off.4

Increased levels of carbon dioxide encourage growth in some plants and decrease the necessary amount of water intake, which could put invasive plants at even more of an advantage over native plants. While both native and invasive plants will respond to increased carbon dioxide, research by Stanley Smith and colleagues suggests that some exotic species may benefit more. Red brome, an exotic grass found in the Southwest, will increase in plant size more than native grasses do under higher levels of atmospheric carbon dioxide. Red brome populations will also increase in density while native grasses populations do not.5

Invasive plants may also respond differently to management practices, like pesticide applications or removal programs, if under the influence of increased carbon dioxide. Common pesticides like glyphosate lose effectiveness on plants growing with increased carbon dioxide in the atmosphere.6 Land managers may therefore need to reassess their techniques to control invasive species.

  1. Theoharides, K. and J. Dukes. 2007. Plant invasion across space and time: factors affecting nonindigenous species success during four stages of invasion. New Phytologist 176 (2): 256-273.
  2. Esque, T., et al. 2007. Buffelgrass fuel loads in Saguaro National Park, Arizona, increase fire danger and threaten native species. Park Science, 24.
  3. Zavaleta, E. 2000. The economic value of controlling an invasive shrub. Ambio, 29(8): 462-467.
  4. Hellmann, J., J. Byers, B. Bierwagen, and J. Dukes. 2008. Five potential consequences of climate change for invasive species. Conservation Biology, 22(3): 534-543.
  5. Smith, S.D. et al. 2000. Elevated CO2 increases productivity and invasive species success in an arid ecosystem. Nature, 408:79–82.
  6. Backlund, P., et al. 2008. The effects of climate change on agriculture, land resources, water resources, and biodiversity in the United States. A Report by the U.S. Climate Change Science Program and the Subcommittee on Global Change Research. Washington, D.C.

Phenology: Changes in Ecological Lifecycles

Friday, September 12, 2008

Lilac flowers bloom with cues from the weather. Caribou give birth at the peak of plant abundance so that their newborns have plenty to eat. In the Southwest, as well as all other parts of the world, variations in the climate trigger life cycle events in plants and animals. Studying these events and their relation to climate is known as phenology. The information obtained is vital for understanding the impact climate change has on humans and ecosystems.

A Gila woodpecker feeding on the flowers of the giant saguaro cactus. The timing of blooming may shift in a changing climate.
Credit: ©Frank Leung,

Phenology includes the timing of flower blooms, agricultural crop stages, insect activity, and animal migration. All of these events are changing as a result of climate change and these changes impact humans. The date flowers bloom, for example, controls the timing of allergens and infectious diseases—impacting human health—and alters when tourists visit regions to enjoy wildflowers, which impacts economies. Variations in crop phases affect agriculture by influencing the timing of planting, harvesting, and pest activity.

Quantitative assessments of the impact of phenological changes on humans in the Southwest are scant primarily because phenology is a relatively recent scientific endeavor in the Southwest. However, increasing concern about climate change has amplified efforts in the following areas:

  • Documenting observed phenological changes
  • Projecting phenological changes from climate change
  • Establishing a national phenological network

Observed phenological changes

Phenology in the Southwest is relatively young and there are only a few observational records more than 20 years old. Nonetheless, records less than 20 years are sufficient to observe trends in phenological changes, and experts believe that changes in life cycle events in the Southwest will be similar to those documented in other parts of the world where longer records exist.

Two of the more important and well-documented effects of climate change on phenology are changes in the date of flowering and food-chain disruptions.

Changes in flower blooms

Studies indicate an advance in the date that flowers bloom in the West. Important conclusions include the following:

  • Shrub specimens collected in the Sonoran Desert of the southwestern U.S. and northwestern Mexico and biological models suggest that the spring bloom of shrubs may have advanced by 20 to 41 days between 1894 and 2004
  • A study published in 2001 concluded that the average date of bloom for lilacs in the western U.S. advanced by 7.5 days between 1957 and 1994, while the average bloom date of honeysuckle advanced by 10 days between 1968 and 1994.
  • A 20-year record of the timing of flower blooms for hundreds of plant species across 4,000 vertical feet in the Santa Catalina Mountains near Tucson, Arizona, suggests more than 15 percent of the surveyed species bloom at elevations as much as 1,000 feet higher than they did in the past.
  • The same 20-year record showed the average total number of species in bloom per year increased over the 20-year period by nearly three species per year at the highest elevations—this increase was associated with increasing summer temperatures.

Food chain disruption

Important life cycle events in plants and animals are often triggered by each other. When the timing of life cycle events changes in one species, it can disrupt symbiotic relationships and affect other species. For example, in the northeastern U.S., nectar-producing trees currently bloom 25 days earlier than in the past. As a result, honey bees have switched their source of nectar from the tulip poplar tree to black locust tree, impacting the pollination of tulip poplars and causing their numbers to crash. In the Arctic, the peak in plant abundance and caribou births no longer coincide, causing a 400 percent jump in offspring mortality.

Projected phenological changes

Future phenological changes will be localized, depending on the specific plant and animal species and the magnitude of climate change. Some species may profit, while others suffer. In general, flowers will likely bloom earlier and food-chain disruptions will likely be more frequent. Several changes are likely in the Southwest:

  • Because the date and abundance of flower blooms are highly correlated with winter snowpack, projected declines in snowpack will decrease flower abundance and advance the date of flowering.
  • Global warming may have a disproportionate effect on montane plant communities. Some mountain species may not be able to respond to changes in temperature by migrating north or south. In addition, an upward shift in altitudinal range of species to encounter cooler temperatures will decrease habitat area.
  • Earlier flower blooms could have substantial impacts on plant and animal communities in the Sonoran Desert, especially on shrubs and migratory hummingbirds.

In addition, climate change will cause plant species to move in response to changes in temperature and precipitation. This may be most evident on mountains, where changes in elevation help create specific habitat zones within small areas. In the Santa Catalina Mountains near Tucson, Arizona, for example, the habitat of many species has expanded upslope, and to a lesser extent downslope.

The main message is that different plants respond differently to climate and other changes.

National phenological network

The USA National Phenology Network (NPN) is headquartered in Tucson, Arizona. Its mission is to facilitate collection and dissemination of phenological data from the United States. NPN primarily supports scientific research concerning interactions among plants, animals, and the lower atmosphere, especially the long-term impacts of climate change.

NPN encourages involvement in phenological research and provides opportunities for interested people to contribute to science. Scholars, students of all grades, and citizens record the timing of life cycle events in key plant and animal species and submit their observations on-line. In this manner, a detailed database is growing. Currently, 800 people in the U.S. participate in NPN. Among them, amateur scientists in the Southwest have provided some of the more valuable and longer observational data.


  1. Bowers, J. E. 2007. Has climatic warming altered spring flowering date of Sonoran desert shrubs? The Southwestern Naturalist, 52(3):347-355.
  2. Cayan, D. R., et al. 2001. Changes in the onset of spring in the western United States. Bulletin of the American Meteorological Society, 82(3):399-415.
  3. Personal communication with Dave Bertelsen, August 4, 2008.
  4. Crimmins, T. H., M. A. Crimmins, D. Bertelsen and J. Balmat. 2008. Relationships between alpha diversity of plant species in bloom and climatic variables across an elevation gradient. International Journal of Biometeorology, 52:353-366.
  5. Personal communication with Jake Weltzin, July 21, 2008.
  6. Inouye, D. W., M. A. Morales and G. J. Dodge. 2002. Variation in timing and abundance of flowering by Delphinium barbeyi Huth (Ranunculaceae): The roles of snowpack, frost, and La Niña, in the context of climate change. Oecologia, 130:543–550.