Within your child or grandchild's lifetime, the weather may be dramatically different because of climate change. The past five years have already been the hottest on record for our planet, but based on new projections published Tuesday in the journal Nature Communications, it's going to get a lot hotter for the 250 million people living in North American cities.
In many urban areas, the researchers from the University of Maryland, North Carolina State University and the National History Museum of Denmark at the University of Copenhagen found "substantial differences" between probable future climate and even the best scenario. That means that by 2080, many cities will probably experience "novel climates with no modern equivalent."
According to the researchers' interactive map, if emissions are not cut and climate change continues as it is, by 2080, summers in New York will feel like those of Jonesboro, Arkansas: an average 9.1 degrees Fahrenheit warmer and 20.8% drier.
If we cut emissions and enact policies that tackle climate change, the change won't be nearly as extreme. By 2080, summers in New York would feel more like those of Lake Shore, Maryland: about 4.4 degrees warmer and 9% drier.
Nearly all cities in the eastern United States, including Boston, Philadelphia and Washington, would have climates much more similar to those of cities hundreds of miles away to the south and southwest.
It's not just the East Coast that could change. The Northeast would be more like the humid parts of the Midwest or southeastern United States. Western cities would be more like the desert Southwest. Cities in Florida would experience summers more like what parts of Mexico has today. San Francisco would have the climate of Los Angeles: 7 degrees warmer and 40% drier.
The change could be particularly problematic in the West, where the study shows that the average distance between cities' future climate and current "climate analogs" might be shorter.
Changes in elevation show just how drastically different the climate could be in the future.
Take Denver, elevation 5,280 feet: The "Mile-High City" is known for its comfortable mountain climate and it depends on tourism featuring winter sports like skiing. But by 2080, according to the study, Denver's climate would be around 9 degrees Fahrenheit warmer and more like that of the Texas Panhandle city of Borger, elevation 3,077 feet.
Climate change planning is well underway in Denver, according to Tom Herrod, a program lead with the Department of Public Health & Environment. The city has a goal to reduce carbon emissions 80% from 2005 levels by 2050. Denver also has done its own climate modeling to create a climate action plan, and the numbers in the new study look similar to those results, Herrod said.
City officials use data sets like these to look at how they should improve building codes and to make sure they aren't just energy-efficient but have the proper air quality inside.
"It's really about adaptation planning and getting as much of the city prepared as possible," Herrod said.
Not a lot of Denver residents have air conditioning, but if the city's climate becomes like Texas', that will need to change, and residents will need to prepare.
"We love seeing studies like these because it's a really good way to bring climate change in front of people," Herrod said. "This really will impact people in their daily lives."
Kristie Ebi said more cities are going to be proactive and think about climate change and its impact on infrastructure.
"Buildings in Chicago are built for cold, for example, not heat. There are so many places without central air, and it is not cheap to put in and not cheap to run, and that's just the start of planning that will need to happen," said Ebi, who was not involved with the new study but who looks at the impact of climate change on health as a professor at the University of Washington's Department of Global Health.
Temperature changes will do more than make summers extremely uncomfortable for people who are used to milder temperatures. The changes will hurt economies and affect such industries as farming and tourism.
Ebi said city health departments need to be thinking about increases in vector-borne diseases, heat-related deaths, allergies and asthma. Worker productivity will fall for those who work outside, and Little League teams will have to change their seasons to avoid the higher temperature.
"This impacts a lot of lives in lots of ways -- and ways people may not be thinking of with these shifts," Ebi said. "Mapping like this is really helpful because it helps people understand how much their own cities will have to adapt."
Urban populations are considered highly sensitive to climate change, the study said. Because most people live in cities, the authors wanted to show people what climate change could mean for them in a real and concrete way.
Lynda Walsh, a professor at the University of Nevada, Reno who has written about impactful ways of communicating about climate change, said she likes this approach.
This approach "doesn't sentence its viewers to climate doom; rather, they're invited to envision a city they have heard of and perhaps even have visited," Walsh said in an email. "This approach has the potential to spark conversation and creative 'what if we... ' responses, rather than hopeless resignation to a global scenario that's beyond any one community's control."
Walsh said the authors are right to point out that the climate-analog approach needs further testing to see if this form of communication works, but, Walsh said, "to a rhetorician of climate, at least, who cares most about promoting democratic deliberation and policymaking around the issue, (the researchers') analogical approach is really promising."
"The good news is, these are projections. Adverse consequence doesn't necessarily have to occur if we take action," University of Washington's Ebi said.
She cites the time when Mothers Against Drunk Driving became a popular group advocating for changes in drunken driving laws.
"A small group of very angry mothers changed all the laws in the United States," Ebi said. "It is possible to make rapid change in short periods of time. We need the collective action and individual action and change. This is possible."