No one knows whether human consciousness will reside on a computer chip by the end of the century or even if self-driving cars will rule the road. But this much is certain: Earth is going to get hotter. The maps displayed here forecast how much warmer our planet will be up through the year 2100 and how precipitation patterns will change. To make the figures, Scientific American worked with Earth scientists at NASA Ames Research Center. The researchers used high-resolution climate models from the Intergovernmental Panel on Climate Change to generate climate data for nearly every point on the planet for every month of every year through the end of the century. Our graphic presents a middle of the road emissions scenario—it assumes that the world curbs greenhouse gases by mid-century but that substantial warming continues to take place.
An estimated 10 billion people will inhabit that warmer world. Some will become climate refugees—moving away from areas where unbearable temperatures are the norm and where rising water has claimed homes. In most cases, however, policy experts foresee relatively small movement within a country’s borders. Most people—and communities, cities and nations—will adapt in place. Below the interactive panel we have highlighted roughly a dozen hotspots where climate change will disrupt humanity’s living conditions and livelihoods, along with the strategies those communities are adopting to prepare for such a future.
Maps by Katie Peek, interactive by Andrew Tubelli; SOURCE: NASA EARTH EXCHANGE GLOBAL DAILY DOWNSCALED PROJECTIONS (NEX-GDDP)
A. Newtok, Alaska, U.S.
If current predictions play out, the Arctic will see more dramatic warming than anywhere else on Earth. The Eskimo village of Newtok is already facing the effects, as coastal storms and thawing permafrost have worn away the land it is built on. The town’s roughly 400 residents voted in 2003 to relocate to higher ground nine miles away, but progress has been slow as residents try to secure approval and funding for roads, houses and an airport at the new site. Newtok’s plight shows that even when a community wants to move, bureaucratic barriers can make the shift difficult.
As seas rise, low-lying island nations may seem like goners—and indeed, the president of the Maldives is trying to relocate much of his country’s population. But geomorphologists in New Zealand have found that the atolls in Tuvalu—an island nation of 11,000 people all living within 16 feet of sea level—are instead expanding. Storms and tides erode the shorelines in some places but create land in others when they deposit sand and gravel. On Tuvalu, villages may face the biggest challenge as they try to reconcile their built environment with shifting landforms.
C. Western U.S.
Over the next century wildfires will occur more routinely and rage more intensely—a trend already apparent in much of western North America, which is growing warmer and drier. Such fires threaten human lives and property. To adapt, experts say forest managers will need to thin high-risk woodlands and homeowners and engineers will need to build with fire-safe materials and design fire-resistant landscaping.
D. Florida, U.S.
By 2100, demographers predict six million people in Florida will live in areas vulnerable to sea level rise (blue and green areas above). A bipartisan alliance of four southeastern Florida counties is currently working to help the region prepare. Efforts include a plan to develop infrastructure that keeps potable water available when seawater floods the drinking water supply. The group is also working to change building height regulations in Key West so that homes could be raised above flood levels.
By mid-century, fishery yields in many tropical oceans may drop by half as fish ranges shift—the result of warming temperatures, salinity variations and changes in habitat. This trend will likely continue through 2100. The falloff will put economic pressure on people who rely on making catches for income. (In some high-latitude oceans, in contrast, fish populations may double.) Brazil has responded with Marine Extractive Reserves, wherein fishers, managers and researchers attempt to balance conservation with the need for small-scale fisheries to continue operating. The model is still under development in Brazil but its principles could guide management in other countries with small fisheries.
F. Lagos, Nigeria
According to the U.N., 84 percent of the world’s population will live in cities by 2100. Yet an estimated 65 percent of the necessary housing has not been built—an opportunity for city officials and planners to construct buildings that are resilient to climate change and to plan for better water and transportation infrastructure. Lagos, for example, is built around a flat coastal lagoon and is already experiencing the effects of sea level rise; resorts on Victoria Island have relocated in response to erosion. Twenty-one million people live in Lagos and its surrounding suburbs—a number that is set to double by mid-century.
Economists at the International Food Policy Research Institute and the University of North Carolina at Chapel Hill have found that temperature changes may drive immigration more strongly than extreme weather events. For example, a recent study that analyzed decades of migration data in Pakistan revealed that although people may leave their homes after a flooding event, they usually move back again after the water recedes. Warm winters, on the other hand, cause the kind of repeated crop failures that shrink the incomes of farmers and are more likely to prompt a family to migrate away permanently.
H. Southern Africa
Climate change will intensify droughts in several parts of the world, including southern Africa, Mediterranean Europe and central and southern North America. In Africa droughts—along with other factors—pose a threat to food security, particularly in regions with rain-fed crops and already tenuous food supplies. Historically, food supply disruptions have prompted rural to urban migrations throughout the continent. Some migrations will be seasonal; in west Africa, for example, families responded to the droughts of the 1980s by sending young adults off after the harvest to earn wages.
I. Middle East
By 2100, heat waves in the Middle East, north Africa and Southeast Asia could regularly reach a life-threatening 120 degrees Fahrenheit—and they may hit more often and last longer than those today. That means these areas may be the first places where deaths caused by climate change become common, especially within groups of people with cardiac issues or respiratory diseases. Climate researchers and policy experts think such a risk will put pressure on residents to migrate.
J. Southeast Asia
Climate scientists expect that by 2100, some parts of Southeast Asia will see an additional 20 inches of rain each year. Most of that precipitation is likely to come in deluges that are both heavier and less predictable than they are today. Even though a single episode of heavy rainfall or flooding may not trigger permanent migration, stronger monsoon seasons could curtail crop yields, which could prompt farmers to migrate—perhaps cyclically, as farmers look to city jobs for extra income during the off-season.
K. Melbourne, Australia
Australia endured a decadelong drought in the late 1990s and early 2000s. Melbourne survived, civil engineers recently concluded, in part because residents were willing to change their water usage habits—flushing toilets less often, for example. Australia, the U.S. Southwest, southern Africa and the Amazon Basin may all see megadroughts—dry spells lasting two decades or longer—in the coming century, and Melbourne’s success could guide their adaptation plans.