Climate Catastrophe? Here's What the U.S. Will Look Like in 2100
We can still turn it around, but here is the world our grandchildren will live in if we don't. By Jean Weiss
You've been hearing about the negative impacts of global warming for years. Sometimes your friends nervously joke about it — "Could land in the Rocky Mountains become beachfront property?" Other times you read with worry the news about forest fires, hurricanes, droughts and heat waves. And you wonder, "Is climate disaster already upon us?"
Scientists say the answer is "yes." We are now experiencing the effects of human-caused climate change and, even if we drastically alter our polluting behavior today, we'll continue to see changes over the next two to three decades. This change is irreversible, and researchers predict it may be worse than the depressing situation Al Gore foretold in "An Inconvenient Truth."
"What happens in the next 20 or 30 years is largely already determined." says Kevin Tranberth, ScD, head of the Climate Analysis Section at the National Center for Atmospheric Research (NCAR). "Carbon dioxide concentrations in the atmosphere have already increased by more than 35 percent since pre-industrial times, owing to human activities. Over half of that increase has occurred since 1970."
Although this prognosis seems dire, there is hope. While we can't change the polluting that has already occurred, we can make changes now that will leave a cleaner world for our children and grandchildren. "One important message to convey is we can very much affect what happens 90 years from now by the decisions we make today," says Jim Hurrell, PhD, a senior atmospheric scientist with NCAR. Tranberth agrees. "If we act now, the benefit comes about 30 to 40 years from now," he says. "We can still have a big impact on what happens in the second half of this century."
But what happens if we don't act now? Here is how your part of the United States could be affected in the year 2100 if we don't turn this around.
Pacific Northwest: Washington, Oregon, Idaho and Alaska
What we could see in 2100: Heavier rains, dramatic warming over higher latitudes and sea-level rise
Climate changes in the Northwestern states as a result of global warming will include heavier rainfall and higher temperatures in cities like Seattle and Portland. The slow steady drizzle so familiar to Northwest residents will change. "Precipitation trends have shown daily rainfall events have become heavier," says Martin Hoerling, PhD, a meteorologist with NOAA Earth System Research Lab. And, he says, that trend is likely to continue. Trenberth says to also expect more intense rainfall, a shorter snow season, earlier snow melt and runoff, followed by water shortages come summer. These changes in river flows could affect salmon and other species.
These same states will experience much higher temperatures, especially in the summer. "By 2100 there will be very dramatic warming over the higher latitudes of both hemispheres," says Hurrell. Studies on temperature changes that have already occurred show that Alaska has experienced a 3.6 degree Fahrenheit increase since 1951 and western states in the U.S. are experiencing warmer summer temperatures. "In the summer time, the greatest warming in the U.S. has been occurring in the West," says Hoerling. "That would be in Washington State, Oregon, Idaho, California and Nevada."
One of the fallouts of this trend is increased air pollution. "Higher temperatures are likely to mean higher concentrations of soft ground-level ozone smog," says Kim Knowlton, DrPH, Senior Scientist in the Health and Environment Program with the Natural Resources Defense Council. And higher temperatures over long periods of time can intensify heat waves that create a threat to public health.
The Northwest will also be affected by the anticipated two to three feet of sea level rise, though cities like Portland and Seattle will suffer less than coastal cities in the Southwest and Southeast. "The sea level rise will be global, but it becomes a problem when three things come together," says Trenberth. "High tides, a higher sea level, and a storm surge. The worst storm surges are associated with hurricanes. You don't get hurricanes in the Northwest, so the Northwest is not as vulnerable as the Southeast in that regard."
Alaska, on the other hand, will be affected more similarly to the Polar Regions in Northern Canada than to the Northwest. The increase in temperature in Alaska will melt permafrost, ice and snow cover on landmasses, creating swampland and an outgassing of methane that will impact plant and wildlife. Bug populations will increase, says Trenberth, along with diseases that are normally kept at bay by cold winters.
Rocky Mountains: Colorado, Utah, Wyoming and Montana
What we could see in 2100: Shorter snow season, early snowmelt, drought, wildfire and water issues
Scientists predict that by 2100 increasingly early snowmelts will put a strain on water supplies in Denver, Salt Lake City and other communities fed by Rocky Mountain rivers. Winter snowpack is a vital part of life in the Mountain West, says Trenberth. "Snow piles up in the winter, melts in late spring and summer, and rivers flow, providing water everywhere." But global warming is changing all that. "In the future, the snow season will get shorter, the snow pack will be less, and runoff could easily occur a month or two earlier," says Trenberth. "Instead of having peak runoff in June, it could happen in April. Then, by the time you get to June, [the entire region] is a lot drier" [than it is now]. The ski industry, now a main source of revenue for Rocky Mountain ski towns, will no doubt be put on notice, as will states downstream from the mountains. Less water in the Southwest will lead to drought conditions, more wildfires and stressed fish and other aquatic species, says Hoerling.
An earlier spring disrupts natural systems in ways that lead to human health issues, says Knowlton. Trees and plants leaf out earlier, the pollen-producing season lasts longer and higher aeroallergen concentrations exacerbate asthma and allergies. Some plants, like poison ivy, become more toxic when there are higher levels of Co2. A longer summer and short winter also allow insects like the pine bark beetle to thrive, threatening the health of trees and contributing to the risk of forest fires.
Northeast: Virginia to Maine
What we could see in 2100: Harsher storms, extreme sea level rise and flooding
The Northeastern U.S. will experience rising temperatures and harsher but less frequent storms if global warming remains unchecked, and will be more vulnerable to sea level rise and flooding than other coastal areas around the country.
The largest metropolitan areas along the seaboard are especially at risk for stronger storms and flooding. "Models suggest that in the future the normal weather patterns that we now have will shift north," says Trenberth. This could extend the risk of hurricanes, though they would be rare, from southern cities such as New Orleans and coastal areas in Florida, Georgia, and the Carolinas to cities as far north as New York and Boston.
East Coast cities will also be more affected by sea level rise than other areas of the U.S. "Today's coastal areas will be very different by the end of this century if we do nothing," says Hurrell. "On average, global sea levels will go up two to three feet." But scientists expect that in some coastal cities, such as Boston and New York, complex ocean currents that will change as our climate changes will add an extra 8 inches to that increase in water level. Rising sea levels could flood subways and underground sewage and transportation systems if left unchecked. Or, these cities could become similar to New Orleans, in that they'd need to build infrastructure like levees to protect them from rising sea levels.
An increase in the number of extreme storms would cause public health issues by creating a higher risk of waterborne illnesses such as cryptosporidiosis and giardia, says Knowlton. Add increased temperatures to the mix and the future just gets darker. Some estimates suggest that at our current rate of climate change, temperature in the Northeast will increase as much as 6 degrees Fahrenheit by century's end. That will make the public health risks during heat waves immeasurably worse than they already are today.
Southeast: The Gulf Coast states, extending up to Carolina
What we could see in 2100: Hurricanes, wind damage, storm surges, flooding, extra sea level rise
The Southeastern states will experience less extreme temperature increases than northern and western states, but they will see stronger storms and find themselves more vulnerable to sea level rise. "All areas within the U.S. have not had similar rates of change," says Hoerling. "If you're sitting in the Southeast, you might scratch your head and say, ‘Where is global warming?'" While the year 2100 will show some increases in temperature for the southeast, so far that increase has been minimal, says Hoerling. "From 1951 to 2006, no net warming has occurred in the southeastern states," he says.
While temperature increase will be less dramatic, effects from sea level rise will be more so. "There are two major factors in terms of sea level rise," says Hurrell. "The first is that as the oceans warm, the water expands as it warms. This is called thermal expansion. The second is that more fresh water will be added to the oceans." Hurrell says that coastal areas in the Southeast will be under water, to the tune of two to three feet, unless we build levees and other systems to adapt to rising sea levels. Because of the same sea current patterns that will create more flooding in Northeastern states, Southeastern cities such as Miami can expect about 2 inches of flooding above the anticipated average global sea rise.
The Southeast can also expect more extreme hurricanes, similar to the conditions that came together around Hurricane Katrina. "There are three main risks," says Trenberth. "There is risk for increased wind damage, risk for a storm surge, which is very coastal and exacerbated by higher sea levels, and then a bit further inland, there is an increased risk of flooding from torrential rains."
Waterborne diseases such as cryptosporidiosis and giardiasis are more likely to fester in a flood zone and will create additional risk to public health, says Knowlton.
The Northern Plains, Midwest and Great Lakes
What we could see in 2100: Stronger storms (tornados, heavy rains) occurring throughout the year and warmer winters
Scientists predict that the Northern Plains, Midwest and Great Lakes areas will experience stronger storms, longer storm seasons and an increase in temperatures. "The greatest warming in the winters in the U.S. has been happening over the Northern Plains, the Dakota territories and the Northern Great Lakes," says Hoerling. Some estimates predict temperature changes as high as 5 to 12 degrees Fahrenheit in winter, and 5 to 20 degrees Fahrenheit in summer by 2100.
Warmer winters can lead to an increase in infectious diseases such as Lyme disease, West Nile virus and dengue fever, says Knowlton, as warmer winter weather allows insect populations to remain active longer each year.
An extended summer will translate to a longer growing season, but also to an increased risk of drought and extreme heat. That heat will create evaporation that will lower water levels, especially in the Great Lakes.
While there will be little change in overall average precipitation, this region will experience longer storm seasons. "The main storms in tornado alley, states such as Oklahoma, Kansas, Illinois, Indiana and Ohio, typically occur in the spring, but more evidence shows that some of these storms may now occur in winter," says Trenberth. And "more messy episodes of freezing rain may occur in mid-winter instead of snow."
Southwest: Arizona, New Mexico, California and Nevada
What we could see in 2100: Drought and water shortages, heat waves and wildfire
The Southwestern states, which in the global warming equation include California and Nevada, will experience intense heat waves, poorer air quality, wildfire, water shortages, drought and expanding risks to agriculture. "In general, the main worry in the Southwest is water resources," says Trenberth. "The area is already semi-arid. Water is already a scarce resource what with increasing population demands. These areas are already quite dependent on water flowing from the mountains, so any changes in snow pack ultimately affects the flows in the Colorado River basin and water sources in places like California."
Dry conditions and high temperatures will increase risk for heat waves and wildfires, says Trenberth. "Along with that come issues with insects and diseases. Some insects, such as the Pine Bark Beetle, flourish with a longer summer season, and the dead trees they create lead to higher wildfire risk.
And then there are the water issues. "The increased heating of the earth's surface not only raises temperatures, but it increases evaporation which makes dry soils even drier," says Hurrell. "Droughts will become more severe, frequent and longer lasting."
"We're already seeing the impacts of climate change on public health," says Knowlton. "Heat waves are just one example. They send thousands of extra people to emergency rooms and hospitals, as our study of the 2006 California heat wave showed." Knowlton says that during that particular episode more than 16,000 excess emergency room visits and 1,200 additional hospitalizations happened in a 2-week period, costing the state of California $133 million.
California will also see a two- to three-foot rise in sea level, while San Francisco will see slightly more than that.
Jean Weiss is a regular contributor to MSN Green.