Scientists have warned for years that the continued burning of fossil fuels may send Earth's ice caps into a near-total meltdown someday, submerging many of the world's greatest cities.
A bombshell new study in the journal Science Advances predicted that if people keep adding carbon to the atmosphere at the same rate they do today, the melting of the Antarctic Ice Sheet alone would commit the oceans to a global rise of up to 60 meters.
At 30 meters of sea-level rise, part of the southwest corner of Arizona will be underwater, says Scott Kulp of Climate Central.
Besides the elimination of most of Florida and large parts of Louisiana and Texas, "the cities lost would include Miami, New Orleans, Houston, Washington, [and] New York," a New York Times article about the study reported on September 11.
As scientists confirmed for New Times last week, the futuristic scenario also predicts a profound impact for Arizona: It becomes a coastal state.
That's right — by then, there'll be no need to travel to Rocky Point anymore (which will be underwater, anyway). Arizona will have its own shoreline. Sea-level prediction maps show the effect clearly, but scientists and the news media have ignored it as they focus on the epic disasters set to unfold in some of the world's largest cities.
As the oceans rise globally, seawater is predicted to fill the lower Colorado River delta and beyond. As coastlines move inland in California and on the East Coast because of Pacific and Atlantic ocean encroachments, the new Gulf of California coastline would extend nearly to Joshua Tree National Park. Say goodbye to Imperial Valley cities like El Centro but hello to a possible seaport near the current site of the Marine Air Corps Station in Yuma.
No need to buy or sell land now, though — none of this will take place for centuries. The Science Advances study predicts that burning the world's store of oil, gas, and coal for the next 500 years will cause an "average contribution to sea-level rise exceeding 3 [meters] per century during the first millennium." Doing the math, that's a commitment of 30 meters in 1,000 years.
At 30 meters of sea-level rise, the currently underpopulated part of the southwest corner of Arizona will be underwater, says Scott Kulp, computational scientist and senior developer for Climate Central, an organization of climate-change experts.
Bob Kopp, associate professor and sea-level expert at Rutgers University, agrees that a 30-meter rise — and an Arizona coastline — could be possible by the year 3000. But he emphasizes that the timescale of these events is extremely long.
"If everything goes terribly, both in terms of not stopping emissions growth and in terms of ice-sheet physics, you might see that by the end of the millennium," Kopp says. "By the time it happens, we might have essentially unlimited energy from nuclear fusion and be spread across multiple planets, or we might be living in a dark age without electricity."
Kopp also notes that these are the worst-case scenarios. His latest estimates show a 90 percent probability for a one- to 3.7-meter rise in global sea level by 2200, a much slower rate of gain. A rise of 30 to 60 meters, he predicts, would take thousands of years.
Clearly, this won't be all good news for Arizona. Scientists predict the state could become much hotter and drier because of climate change — lying on the beach might not be fun if it's 130 degrees.
Intense flooding elsewhere in the country, not to mention the world, will cause economic and other problems expected to negatively affect Arizona. South of the border, Mexico would find itself without a land bridge to Baja California.
But maybe the recreational and commercial opportunities in Arizona's far-flung future would help the state overcome the challenges.
Scientists still are studying how global warming will melt the world's ice and add to the height of the oceans, and they're far from certain how it will all unfold, or when. A recent study published in the Geology journal, for example, concluded that even in a worst-case scenario the oceans might rise no higher than 9 to 13.5 meters.
This week, a NASA study made waves with the striking news that it's snowing so much in Antarctica that the continent has gained more ice than it's lost in recent years, reducing global sea levels by a tiny amount.
(This story originally was posted October 16.)