That Unwelcome Stranger Called Climate Change

By Allen Best

Adapting to climate change might be easier if those changes announced themselves by rapping on your door and thrusting business cards into your hand. Instead, they blur like a fast-changing crowd.

Consider the algae blooms that have clogged harbors, killed fish, and imperiled the tap water of cities depending on western Lake Erie. The blooms have occurred naturally in the past, but not with the same frequency, eight out of the last nine years.

The biggest bloom occurred in 2011, turning an estimated 1,930 square miles, an area larger than Rhode Island, into something that resembled pea soup. The blooms produce toxins that can overwhelm water-treatment plants drawing on the lake. In August 2014, authorities warned 400,000 residents of the Toledo area against using tap water for two days. The National Guard helped to distribute fresh, drinkable water.

Scientists easily linked the blooms to runoff of phosphorous-rich fertilizer spread on Ohio farms to maximize crop production. There's also a connection to rising global temperatures. Lake Erie is shallow and warms easily, favoring algae growth. But there's another, less obvious link to global warming: more intense rainstorms that sweep the phosphorous into rivers flowing into Lake Erie.

"Intense spring rainstorms were a major contributing factor, and such storms are part of a long-term trend for this region that is projected to get worse in the future due to climate change," says aquatic ecologist Donald Scavia, director of the University of Michigan's Graham Sustainability Institute. Scavia was among the 29 authors of a 2013 paper published in the Proceedings of the National Academy of the Sciences that warned of the need to reduce phosphorus runoff — or face the prospect that the massive 2011 algae spread would be a "harbinger of future blooms in Lake Erie."

Data from the 2014 National Climate Assessment shows that every region in the U.S. was warmer during the period from 2001 to 2012 than in the previous decade. Not every region saw equal increases, though. Georgia, Alabama, and other states in the Southeast saw relatively little temperature increase, while Alaska, the Southwest, and the Northeast all experienced significant warming. Source: NOAA NCEI/CICS-NC

Certainties

Changes in the climate are being observed all around. The most recent decade had twice as many record highs as record lows. The frost-free season lengthened across the country but especially in the Southwest, where it was 19 days longer from 1991 to 2012 than during the first six decades of the 20th century. Ice cover in the Great Lakes has declined substantially, allowing more shipping during winter but also providing more moisture for massive snowstorms in places like Buffalo, New York.

"Evidence for changes in Earth's climate can be found from the top of the atmosphere to the depths of the oceans," says the third U.S. National Climate Assessment, published in 2014. "The sum total of this evidence tells an unambiguous story: the planet is warming."

The report, both in text and in an interactive website, paints a crisp image about what is known about climate change in the U.S. Temperatures have increased an average 1.3 degrees to 1.9 degrees Fahrenheit since recordkeeping began in 1895, but most of that increase has occurred since 1970. Even if emissions slow substantially, according to 16 climate models, temperatures will still rise three to five degrees. With a high-emissions scenario, we end up with a five- to 10-degree temperature rise.

Yet, for those seeking to develop adaptation strategies, it's important to understand that the temperature is not changing uniformly. Neither are future changes in the climate expected to be uniform. Georgia, Alabama, and other Southeastern states have had very little temperature increase, but Alaska is getting relatively toasty.

Then there is that background noise of natural variability. We've had droughts, floods, and heat waves before. And right now, scientists have mixed opinions about how many human fingerprints can be detected on such things as Superstorm Sandy, the California drought, or the 2012 heat waves in Oklahoma and Texas. They do agree, though, that such extreme weather events will become more common.

Regional takes

For planners, the regional snapshots and the sector-by-sector sections of the national climate assessment may prove most useful. Alaska and Florida obviously have different narratives, but so do the Great Plains and the Pacific Northwest.

Katharine Jacobs, who directed preparation of the National Climate Assessment when in the White House Office of Science and Technology, sees cities and other local jurisdictions taking the lead in adapting to climate changes. "The city is the unit of government that can actually make decisions and build things. It is much more difficult at larger scales to manage climate impacts, because they tend to be local in nature, and the type of adjustments that need to be made are specific to specific places," she says.

From her four years in Washington, D.C., Jacobs sees the most interesting work occurring in coastal states. Sea-level rise is undeniable, she points out, and it's much easier to deal with issues that are already visible. However, land-use, transportation, and water planners already understand the need to plan for greater variability: more flooding, more drought, less snowmelt. "There are some pretty obvious things planners can do," she says, "such as design roadways to withstand more intense heat."

Jacobs, who worked for 23 years in water matters in Arizona, sees climate changes in terms of water. "We feel the impact to climate through changes in the water cycle," she says. "Lake Erie is an example, but one of several thousand examples."

Having returned to Tucson, where she directs the Center for Climate Adaptation Science and Solutions, Jacobs sees the effect of higher temperatures in the Colorado River Basin, where Lake Mead and other reservoirs have gradually been receding. This is, she says, the result of increased evaporation and transpiration.

"The changes in temperatures are having a great impact on water supplies in ways that people didn't previously recognize," she says. "It's not just changes in precipitation. It's also changes in temperatures."

Heat islands

The climate assessment delivers several key messages. One is that heavy downpours, sometimes called "frog-stranglers," have already increased. Assessing records since 1991, the report finds a 30 percent gain in precipitation in Northeast, Midwest, and upper Great Plains as compared to the 1901–1960 average. The future? Climate models suggest that when it rains, it will pour even more — even in places like Arizona, which otherwise will veer toward greater drought.

Heat waves have become more frequent and intense in recent decades, but it's hard to pick out anomalies. The assessment points out that the meteorological situations causing heat waves are a natural part of the climate system, but extreme heat days that typically occurred once in 20 years are projected to occur every two or three years by century's end.

Future heat waves are a central concern of Nicholas Rajkovich, an assistant professor at the University of Buffalo's School of Architecture and Planning. Among his research questions is how buildings will react to the changing environment, whether hurricane storm surges or July heat waves such as the one that killed 650 Chicagoans in 1995. Extreme heat, he says, kills more Americans each year than any other natural disaster, including tornadoes, hurricanes, and lightning. According to the Centers for Disease Control and Prevention, extreme heat exposure caused or contributed to more than 7,800 deaths from 1999 through 2009.

With partners, including a team from Kent State University, Rajkovich has been spending time in Cleveland, where an essential task is to help prepare for increased heat. As described by sociologist Eric Klinenberg, in Heat Wave: A Social Autopsy of Disaster in Chicago, the victims there were disproportionately elderly, African American, and poor. Many of the victims died alone.

The Kresge Foundation, based in Troy, Michigan, supports the work in Cleveland as part of its Climate Resilience and Urban Opportunity Initiative. "Climate change is a threat multiplier," the foundation says in a position paper. "Social variables such as age, income and health or disability status often determine community residents' ability to prepare for, respond to and recover from hazardous events. In addition, low-income neighborhoods often are located in areas that have greater exposure to hazards such as flooding or extreme heat."

The foundation believes that efforts to attain climate-resilience goals must address the unique circumstances of low-income populations. That requires systematic engagement of leaders and advocates who authentically represent the concerns of low-income community members.

Working with the Cleveland Neighborhood Association and the Kent State University Urban Design Collaborative, Rajkovich is exploring how vacant land can be used to combat the heat island effect. (Trees planted on vacant lots can provide shade and reduce heat buildup, and the lots can also be used for rain gardens or stormwater detention.) Cleveland's population peaked in the 1930s and has declined ever since, Rajkovich points out. Many houses have been demolished. "If you can begin to use that vacant land as a strategy to address climate change, it seems like a win-win in many ways," he says.

Rajkovich points out that Chicago, New York City, Philadelphia, and other cities have started innovative programs to address heat waves. But he also notes that heat is not the same problem everywhere. Just half of Cleveland homes have air conditioners. Atlanta is more accustomed to heat and is less vulnerable.

Increasing algae blooms threaten the Great Lakes

The Operational Land Imager on Landsat 8 took this image of algae blooms (the green swirls) in western Lake Erie and Lake St. Clair in July 2015. Algae blossom when there is an abundance of nutrients — many from agricultural runoff — along with sunlight and warm water. Harmful algae blooms can lead to fish kills and can threaten water for drinking and recreational use, as they did in Toledo, Ohio, in 2014. NASA and several partners are working to develop an early warning indicator for harmful blooms in fresh water. Courtesy NASA

Cause and effect

Other researchers have been focusing on heat vulnerability and the urban heat island effect. A team of researchers led by Colleen Reid of the University of California at Berkeley's School of Public Health have sought to map community determinants of heat vulnerability. In echoes of Chicago's 1995 disaster, they found four factors explained more than 75 percent of the total variance in vulnerability, among them social isolation, the elderly and those with diabetes, and the absence of air conditioning.

But a team of researchers from the National Center for Atmospheric Research and the City University of New York in May issued a paper declaring that Americans' overall exposure to future heat waves would be vastly underestimated unless demographics were taken into account. The study, published in the journal Nature Climate Change, points to projected population growth in Atlanta, Charlotte, Dallas, Houston, Oklahoma City, Phoenix, Tampa, and San Antonio.

In figuring out adaptation strategies, nongovernment organizations and others also must measure success. Missy Stults has dived into that question as part of her doctoral studies in urban and regional planning and the natural resources and environment at the University of Michigan. For six years, she was national climate director for ICLEI-Local Governments for Sustainability, where she worked with 600 local governments to advance their climate mitigation and adaptation efforts.

Stults attended the National Adaptation Forum, held in May in St. Louis, where she conducted 21 interviews with participants to understand what they're doing, why, and with what success. "We live in a society where people want metrics, and if you applied for a federal grant, right now you would have to tell them exactly what you are going to do and what the value will be," she says.

Universal metrics are elusive, though. "Not everyone is facing the same impacts," she points out. "In the Southwest or California, drought is a huge, huge issue. But here in Ann Arbor, drought is not a huge driver. ... The conversation in our field is, 'Are there generic metrics and what are they?' If the answer is no, then how do you create an accountability that allows researchers, federal agencies, governors, and others to know whether investments are making a difference?"

Both the words "adaptation" and "resiliency" were used liberally in conversations at the National Adaptation Forum. To some, they're interchangeable. Stults sees a difference: Adaptation is about preparing for impacts and emerging at the other end. Resiliency is not just about surviving but also thriving with climate changes.

Stults learned that many of the forum participants are working hard in their local communities to educate others about climate-change issues. The need for education can be frustrating, she says, because threats have been reasonably well defined. But by building awareness and support, elected officials will be on board, and citizens will do the things needed to actually increase resilience. Those who were achieving success, she says, often told her it was because of political support. Local, visual presentations to elected officials were most compelling, such as images of people's lawns flooding from high tides in the rising waters off Florida.

Stults reserves her most effusive remarks for staff members in planning offices who are "pushing the issue day in and day out. They are, in my opinion, making things happen, and they get very little credit for it."

And what of those who must deal with lingering uncertainty? That was also a theme at the adaptation forum. One session focused on scenario planning — also called robust decision making — which seeks to identify pathways that embrace uncertainties. Water managers in Colorado, whose population of 5.3 million is projected to increase to nine or 10 million in 35 years, are strapped to make decisions about infrastructure when it's unclear whether there will be more precipitation or less — let alone whether these new residents will actually appear.

"Uncertainty is part of life," Stults says. "Don't let it be the thing that causes you to stop taking action."

Allen Best is based in Denver. He is a frequent contributor to Planning.

Resources

The National Climate Assessment: http://nca2014.globalchange.gov

From the Environmental Protection Agency: http://www3.epa.gov/climatechange/adaptation/