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BOULDER, Colo. — Hurricane Katrina wreaks havoc on the Gulf Coast in 2005. Superstorm Sandy brings destruction to the East Coast in 2012. Heavy rains in the middle of the country lead to flooding in the rugged Rocky Mountains in 2013.
Each crisis brings greater urgency to preparations for the next storm. Scientists disagree on whether climate change is causing these cataclysms, but agree that humans, whose carbon emissions have altered the environment, need to change their thinking and habits to reflect the new, powerful effects of disastrous weather.
"All weather events these days are affected by climate change," argues Kevin Trenberth, a senior scientist at the National Center for Atmospheric Research in Boulder and a lead author of several assessments by the United Nations-backed Intergovernmental Panel on Climate Change (IPCC). Extreme events like Sandy "are developing in an environment that is different than it would have been without climate change," he told Al Jazeera. For instance, climate change has made our world wetter, meaning storms pack more water power: "It rains harder, the storms tend to be a bit stronger," Trenberth said.
Environmental impact is cumulative. Take Colorado, for instance, where scientists say a native beetle that would have been kept in check by periodic cold weather thrived during warmer winters. This upset a balance that had kept beetles from infesting and killing large swaths of forest. That damage, combined with drought — like warming winters, a phenomenon Trenberth links to climate change — killed an inordinate number of trees. The dead, dry wood helped fuel major forest fires. When the fires were followed by heavier rains than usual, little vegetation was left to hold back the soil, leading to land- and mudslides this September.
The force of Colorado's floods left roads buckled as if by an earthquake and ripped away bridges. Sodden hillsides slid into valleys transformed into collages of destruction: strewed with boulders big as Fiat 500s, chunks of concrete the size of car bumpers, tree roots, and household goods from homes upstream. Such an extreme weather event "doesn't happen every year," Trenberth said. "It doesn't happen every week. But it will happen again."
Extreme is rare
Roger Pielke Jr., director of the University of Colorado's Center for Science and Technology, has little patience for those who link extreme weather events to climate change. While he is no climate-change denier, he does not believe it has contributed to more frequent or increasingly intense storms, since weather patterns have always included extreme events. He says those who claim otherwise are trying to find a way to wake the world up to the consequences of global warming.
"The problem with that strategy is that there isn't the science to back it up," Pielke told Al Jazeera. He points out that the IPCC itself has said that scientists can only express "low confidence" the world is seeing more storms or floods.
The panel says scientists are more confident about the implications of some changes than others—for instance, the increase in precipitation. And it says the "low confidence" assessments are due to lack of data or variations in how data has been collected and recorded from region to region and over time.
"Extreme events are rare, which means there are few data available to make assessments regarding changes in their frequency or intensity," the panel said in a 2012 report.
Neither Pielke nor Trenberth, though, think people on the ground should wait for the scientific debate to be settled before taking action that could save lives and property. "Our best strategy is just to prepare for the unexpected," said Pielke, who has tracked a worrisome rise in the financial impact of weather disasters. That is a result, he explained, of "how much value we put in harm’s way."
Pielke said urban planners cannot afford to become complacent and allow development in vulnerable places.
Both in the developing and developed worlds, planning and assertive action can reduce the effects of environmental disasters. In the 2012 report, the IPCC cited steps taken in Mozambique, where flooding in 2000 killed more than 700 people and forced more than half a million from their homes. After that disaster, the government took steps that included moving some 59,000 families from areas vulnerable to flooding, and the international community lent expertise in such areas as improving forecasting and developing an emergency-alert system. When floods similar to the disaster in 2000 hit in 2007, the toll was markedly lower: 29 people killed and 140,000 displaced.
In Colorado, a series of deadly forest fires in 2012 also led to changes in emergency-response planning, including improvements in warning systems. Suzanne Bassinger, recovery manager in Larimer County, in the north-central part of the state, which was hit by fires in 2012 and by floods this year, said her position was created in the aftermath of the fires.
A website initially set up to help county residents find shelter and other assistance after the fires was revived in the wake of the floods, Bassinger told Al Jazeera. "We had that up and running right away."
Now, county officials will be considering revised building codes to ensure that new structures are better able to withstand similar threats. "We're in a different cycle," Bassinger explained. "We're getting more and more prepared."
In a region whose natural beauty attracts tourists as well as long-term residents, officials are also examining the effects of climate change on open spaces. Boulder, set in a dramatic landscape where the Rocky Mountains meet the plains, prides itself on a long history of environmental awareness. The city maintains 45,000 acres of forests, grasslands and wetlands — holdings that are home to 700 species of plants, 59 species of mammals and more than 100 species of birds.
The surrounding county of the same name was the one hardest hit by the heavy rains and flooding in September. Land- and mudslides across some 2,000 square miles contributed to the deaths of at least eight people and caused widespread damage to homes, businesses, roads and bridges.
Jim Reeder of the city's Open Space and Mountain Parks Department said flooding damaged 75 percent of the 146 miles of trails overseen by the department. He wants to rebuild them but with better infrastructure. A bridge ripped away by floodwaters that might cost $75,000 to replace in accordance with the old standards could cost twice that if the new structure is to withstand future floods, he explained. Overall, Reeder told Al Jazeera, he expects rebuilding in the parks to cost as much as $18 million — nearly four times the 2013 budget for his department.
The public has been pushing to get back into the open spaces — a desire expressed at public meetings and illustrated by an outpouring of offers from volunteers eager to help clear trails. But Reeder has proceeded cautiously, out of fear for the safety of the volunteers as well as concern about the impact of hiking boots and mountain bikes on fragile ecosystems.
As the rains were falling, Open Space and Mountain Parks teams were called to a spot on one trail where floodwaters were rushing toward homes. "We looked at that and said, 'We need to get the water back into the creek,'" Reeder said. Makeshift dams were built and the water was directed back to its original course. But that may have simply pushed the destructive force on to areas downstream. City, county, state and federal officials will have to communicate and cooperate, as will private and development agencies, Reeder said.
Bruce Stein, director of climate change adaptation for the National Wildlife Federation and a botanist by training, is helping to write a guide for "climate smart" conservation that will aid park- and nature-reserve managers.
"Conservation is by its nature conservative," he told Al Jazeera. "Because we've lost so much, we've focused on preserving what little we have or trying to put things back the way they were. In a climate-altered future, it's going to be very uncomfortable, but we have to acknowledge that that whole paradigm is going to be shifting. Many of our management strategies were predicated on the idea that the future will be more or less like the past. When we rebuild after disasters like the recent floods, it doesn't make sense to rebuild according to the patterns of 40 years of past-rainfall records."
Stewards of America's wild areas may be looking at a future in which they can no longer sustain plant and animal species in the places they once did. "It can't just be the same old ways of doing business," said David Wheeler, executive director of the Conserve Wildlife Foundation of New Jersey.
Events like Sandy, which smashed New Jersey's coastlines a year ago next week, "have to be things that we learn from," said Wheeler. "We can't just assume that they are 100-year events and won't happen again. In New Jersey, it seems like we're having 100-year or 50-year storms every few years. That's how we know it's a different landscape that we're working with here."
Wheeler's foundation is working with other groups to create wetland habitats in New Jersey for endangered tiger salamanders on sites they hope will be safe as sea levels rise. "This is an innovative project," he said. "We want to see if it might be replicable for different species."
Stein said it can be discouraging to hear so much bad climate news: "It's very hard for individuals to feel like there's anything meaningful they can do, [but] there are things we can begin doing now that will make a difference."
In Colorado, plant ecologist Lynn Riedel runs a gloved hand along a stalk of tall prairie grass. Some of the seed she is collecting in a meadow on Boulder's outskirts will be used to replant areas devastated by the September floods. The rest will be stored for the aftermath of future disasters.
"We're going to have more flooding because of climate change," said Riedel.
That means just one thing: "We definitely need to be ready." The flooding "has caused us to realize how flexible we need to be," she concludes, "how adaptable we need to be."