On July 5, a massive dust cloud, or haboob, swept across Phoenix, Arizona, brought by the North American monsoon. (Photo: Greg Gorman/Flickr)

By Alyson Kenward

On Tuesday night, a massive dust storm rolled into Phoenix, Arizona knocking out power in much of the city, reducing visibility to nearly zero, and grounding flights overnight. Photos of the 100-mile wide dust cloud swallowing the city circulated yesterday, and the event looked practically apocalyptic. In fact, if the photos weren’t in color, and there weren’t YouTube videos of the dust storm, I would have thought I was looking at old-timey images from the 1930’s dust bowl. Now, a couple days later, lingering dust in the air has triggered allergy-like symptoms for many people.

This isn’t the worst dust storm Phoenix has endured, mind you; not by a long shot. This kind of immense dust cloud, known as a haboob, can stir up in the Southwest during North America’s monsoon season, and Phoenix can see several of these each year. According to Wunderblog’s Jeff Masters, last night’s storm was brought on by:

…a large complex of thunderstorms known as a mesoscale convective system (MCS) that developed to the east of Phoenix. As the outflow from the MCS hit the ground, large quantities of sand and dust became suspended in the air by 50-60 mph winds.

Tuesday’s intense monsoon thunderstorm drove heavy winds down across the dry land, and whipped it up into a dust cloud that pushed ahead of rain that accompanied the storm.

If you’re like me, you might not know much about the North American monsoon, but the Climate Assessment for the Southwest (CLIMAS) has a helpful website on the subject. With help from a couple of scientists at the University of Arizona, the site tackles the tricky question of how climate change might impact the monsoon, which brings beneficial rains to the region.

As Chris Castro and Dave Gutzler write, there is still a lot of uncertainty about how the monsoon might change, if at all, because “the current generation of global climate models doesn’t come close to any consensus as to what the expectation is for a changed monsoon.” In the past 100 years, there hasn’t been a detectable change in how variable the monsoon can be. However, they warn, warmer climates tend to reinforce the monsoon. As global temperatures increase with increasing greenhouse gas emissions, scientists predict the American Southwest will see a corresponding rise in temperatures, by 4-10°F, in the coming decades.

A more prominent monsoon might sound inviting for the region, where 20-50 percent of average rainfall comes during the stormy summer months. The extra rainfall replenishes reservoirs and moistens farmers’ fields temporarily during an otherwise hot, dry season. The intense thunderstorms can also cause flash floods in some areas, ignite wildfires in others, and, as we saw the other day, stir up massive dust clouds that drive ahead of the rain.

As for the dust, new research suggests increasing temperatures in the Southwest (and specifically along the Colorado Plateau) could create more dust in the region. Hotter average temperatures mean the region could become even drier than it is already, making it harder for perennial grasses and plants to thrive. Without these grasses to keep the soil intact, it’s a lot easier for wind to pick the dust up off the ground. Even though the monsoons bring rainfall that can tamp some of the dust down, clouds like the one that formed on Tuesday stir up ahead of the rain, so drier ground in general could still contribute to these monstrous haboobs.

In general, scientists predict that the entire Southwest is going to get drier over the next century, which means that, on average, annual precipitation will be lower than it is today. That doesn’t mean, however, that the monsoon season could become more prominent and bring more rainfall during the summer — there just isn’t any consensus yet on how much the summer rain will offset the overall trend towards warmer and drier conditions.

A version of this post also appears at Climate Central, a content partner of Climate Watch.

Flooding along San Francisco's Embarcadero during an extreme high tide in February. (Photo: Heidi Nutters/Flickr)

Even if the world stopped emitting all greenhouse gases today, scientists say, the climate would continue to change, perhaps for centuries, before it stabilized.  Since a zero-emissions world is unlikely, to say the least, and considering that global carbon emissions are continuing on their upward trend, finding ways to adapt to what many see as inevitable is getting more and more attention.

The San Francisco Planning and Urban Research Association (SPUR), a local think tank focused on sustainable growth, has just released a 40-page report that outlines the Bay Area’s biggest climate risks and lays out a road map for how communities can start preparing.

The upshot?  We’ve got a lot of work to do.

“We need to beginning planning on many fronts because climate change is going to affect the way we do business. It’s going to affect everything from people’s health to property values on the shoreline,” said SPUR’s Laura Tam.

The report finds that the climate change impacts most threatening to the Bay Area are more intense heat waves, water uncertainty (droughts, wildfires, extreme storms and flooding), and sea level rise. It lays out step-by-step instructions for addressing these risks, in terms of public safety and health, water supply, transportation infrastructure, biodiversity, and the region’s energy supply.

Heat waves are a big focus of the report, which, if you live in San Francisco like me, may seem improbable.  Yet, Tam says it’s exactly places like San Francisco that are most vulnerable to increased heat waves because we’re not prepared for them.  (How many people here do you know with air conditioning?)

The report says that by 2100, the Bay Area may experience between 74 and 90 days above 81 degrees Fahrenheit per year.  Throughout the 20th century, the Bay Area averaged about 12.  An increase like that means greater risk for heat-related illnesses and some infectious diseases, as well as poorer air quality.  To address this, SPUR recommends communities identify vulnerable populations, reduce the “urban heat island effect” by promoting white roofs and urban forestry, build communications and public warning systems, and develop robust “heat response plans” and air quality monitoring programs.

Will Travis, the executive director of the San Francisco Bay Conservation and Development Commission (BCDC) and a SPUR board member, said that cash-strapped cities and towns have been “reticent” to deal with climate change adaptation because it can seem like a problem of the future.  But, communities are going to have to act soon to avoid a crisis that’s both environmental and economic, he said.

“Our region is not going to be able to remain competitive and attract the capital we need to make our innovative economy grow if we don’t address this problem right now,” said Travis.

According to BCDC, the Bay Area may see 55 inches of sea level rise by 2100. The SPUR report says that means more than 186 miles of major roads (including I-80, I-880, U.S. 101, Highway 37, I-680, and Highway 12), more than 105 miles of regional rail track, and 93% of Oakland Airport and SFO property will be vulnerable to flooding.

“That transportation infrastructure is the lifeblood of what makes our economy work,” said Travis. “We need that mobility, so we’re going to have to be retrofitting those facilities to make sure that they don’t go underwater.”

The report recommends agencies conduct a comprehensive transportation vulnerability assessment, design resilient new transportation projects, and develop emergency transportation alternatives for cases of extreme weather events.

The report is dense and detailed, and it’s a sobering look at exactly how much needs to be done to prepare for what many state and regional agencies agree is likely on its way. Odds are, none of this will be cheap. And yet, according to SPUR’s Laura Tam, beginning to deal with climate change impacts now could save money as well as lives.

“If we don’t start planning ahead and preparing, we will end up dealing with crises that emerge as emergencies, and we don’t want to be in the position of having to respond to climate emergencies,” she said.  “We want to know what to expect, and be prepared, so that the least amount of property is damaged and the least amount of people suffer.”

A hillside near Mexico City (Photo: Carlye Calvin, UCAR)

Compared to most of the world, California would appear to have a head start in planning for a changing climate.

Cities across the world are not doing enough to protect citizens from the likely impacts. That’s the finding of a new analysis from the National Center for Atmospheric Research (NCAR) in Boulder, CO. The report says cities are unprepared for rising seas, intensified heat waves, while failing to curb their own greenhouse gas emissions.

The failure to act doesn’t bode well for the billions of people who live in cities around the world, according to NCAR Scientist Patricia Romero Lankao, who came to her findings through an in-depth analysis of urban policies.

More than half the world’s population lives in cities. That proportion continues to grow, especially in small-to-medium sized urban areas, where infrastructure is often limited, according to the study. In developing countries this often means substandard housing, and neighborhoods springing up in vulnerable areas such as flood plains or hillsides. Climate change could exacerbate already difficult conditions in these urban areas by bringing more extreme weather events, such as floods, heat waves, and droughts, to places ill-equipped to deal with them.

The study cites three main reasons for cities’ failure to prepare:

• Fast-growing cities are overwhelmed with other needs,
• Civic leaders are often under pressure to downplay the need for health and safety standards in order to foster economic growth, and
• Climate projections are rarely detailed enough to predict impacts on individual cities.

Cities also are not doing all they could to reduce their own emissions.  The NCAR study finds that, rather than imposing construction standards that could save energy or guiding policy to reduce automobile use, many local governments are taking a “hands-off” approach.

“Cities can have an enormous influence on emissions by focusing on mass transit systems and energy-efficient structures, but local leaders face pressures to build more roads and relax regulations that could reduce energy use,” said Romero Lankao in a written release.

Here in California, Senate Bill 375 takes aim at exactly that problem.  By requiring regional and local authorities to work together to find ways to reduce driving (as measured through vehicle miles traveled), the law is designed to help California reach its greenhouse gas emissions reductions goals.  Different regions across the state have different reductions targets for per-capita emissions from passenger vehicles, but most fall in the range of a 7% reduction by 2020, and 13% by 2035.

“California is getting there,” said Michael Schmitz, the California Director for ICLEI-Local Governments for Sustainability, a membership association of more than 1,000 local governments worldwide (600 in the US) that aims to “advance climate protection and sustainable development.”

He said that while cities like Vancouver, British Columbia, and others in Japan and Australia are ahead of California in terms of acting decisively to mitigate emissions and to adapt to climate change, cities in California are leading the way in the United States. That’s largely due to action at the state level, said Schmitz who credits the state’s AB 32 and SB 375 laws with creating a framework for local governments, regional authorities, and the state to work together on climate change issues.

“We see in California cities that the biggest adaptation issues are sea level rise, constraints on water supply, and public health concerns from increased heat days,” said Schmitz.

He cited San Mateo County, Chula Vista, Greater San Diego, and the Bay Area as among California’s leaders because all have begun “vulnerability assessments,” to gauge how climate change could affect local infrastructure, public health and safety.  Another example, is the city of Ventura, which has already begun to act, he said, by relocating oceanfront bike paths and parking lots in anticipation of sea level rise.

“Cities have the most direct control over land-use decisions and public health infrastructure, and they can have the biggest impact on behavior changes,” said Schmitz. “They have the ability and the burden to be able to address and adapt to climate change.”

Learn more about projected climate change impacts in California from this 2009 report from the United States Global Change Research Program.

Climate and Nature
by Anthony Barnosky

Some impacts of climate change in California are pretty obvious, things like rising sea level submerging large parts of the San Francisco Bay region, or drought cutting into our water supplies.  Less obvious, but every bit as important, are impacts on something you probably don’t even know you have: your relationship with nature.

One part of that relationship is the concept of “ecosystem services;” the direct benefits you get from nature.  California’s Climate Action Team highlighted some of the state’s ecosystem services in their recent report.  Examples include the ski trip you may have taken this winter, the salmon fillet you may have bought at the grocery store, or surprisingly, even your hamburger.

Snow will be less, soggier, at higher elevations, and on the ground for fewer days of the winter, melting some of the $500 million-per-year revenues of the ski industry–not to mention melting your favorite ski run.  Altered river dynamics and temperatures will almost certainly cut into the state’s $33-million-per-year salmon industry. Climate-caused loss of forage means that in 2070 California’s cattle ranchers will be losing up to $92 million in comparison to today’s markets, which means higher beef prices at the grocery store.  Combined, the losses in these ecosystem services likely will cost the state’s already suffering economy well over a hundred million dollars per year as we move into the next few decades. And those are just three of many ecosystem services that will be affected.

A second part of your relationship to nature is the species around you, that is to say, biodiversity. Simply put, biodiversity is which species live in a place, and the extent to which those species are rare or common.  In general, biodiversity means more productive and healthier ecosystems, which translates as more benefits to humans that inhabit those areas.  As it turns out, California is a globally recognized biodiversity hotspot, unique in the world.  But biodiversity losses from global warming promise to be severe: one study predicts that two-thirds of the 2387 plant species found only in the state will lose 80% of their range within the century.

The third part of your relationship to nature is how it makes you feel.  There’s no question: you can’t get the same feeling you get looking at a giant redwood anywhere but in a redwood forest.   Among species that may have little or no suitable climate left in California, however, are its coastal redwoods and sequoias.

Such impacts of climate change on nature are not confined to California.   Many other reports indicate that global warming is redefining our relationship to nature worldwide.  As with other impacts, this one can be partially mitigated by reducing greenhouse gas emissions immediately, but also will require some new management strategies for preserving nature in the age of global warming.  California, in particular, has a lot to lose.

Anthony D. Barnosky is a Professor of Integrative Biology at the University of California, Berkeley and author of the recently published Heatstroke: Nature in an Age of Global Warming. You can read more on this topic in his blog. Photos by the author.

Barnosky is scheduled to appear Saturday as part of Berkeley’s “Cal Day” activities. His talk is scheduled for noon at the Valley Life Sciences Bldg, Room 2060, followed by a book-signing at the T-Rex (which is hard to miss).