SANTA CRUZ PROVINCE, ARGENTINA - NOVEMBER 27:  Ice calves at the Perito Moreno glacier in Los Glaciares National Park, part of the Southern Patagonian Ice Field, the third largest ice field in the world, on November 27, 2015 in Santa Cruz Province, Argentina. The majority of the almost 50 large glaciers in Los Glacieres National Park have been retreating during the past fifty years due to warming temperatures, according to the European Space Agency (ESA). The United States Geological Survey (USGS) reports that over 68 percent of the world's freshwater supplies are locked in ice caps and glaciers. The United Nations climate change conference begins November 30 in Paris.  (Photo by Mario Tama/Getty Images)
Mario Tama/Getty Images South America/Getty Images
SANTA CRUZ PROVINCE, ARGENTINA - NOVEMBER 27: Ice calves at the Perito Moreno glacier in Los Glaciares National Park, part of the Southern Patagonian Ice Field, the third largest ice field in the world, on November 27, 2015 in Santa Cruz Province, Argentina. The majority of the almost 50 large glaciers in Los Glacieres National Park have been retreating during the past fifty years due to warming temperatures, according to the European Space Agency (ESA). The United States Geological Survey (USGS) reports that over 68 percent of the world's freshwater supplies are locked in ice caps and glaciers. The United Nations climate change conference begins November 30 in Paris. (Photo by Mario Tama/Getty Images)
Now playing
01:48
Undeniable climate crisis facts (2018)
WASHINGTON, DC - JUNE 13: Rep. Michelle Lujan Grisham (D-NM) speaks during a news conference on immigration to condemn the Trump Administration's "zero tolerance" immigration policy, outside the US Capitol on June 13, 2018 in Washington, DC. (Photo by Toya Sarno Jordan/Getty Images)
Toya Sarno Jordan/Getty Images
WASHINGTON, DC - JUNE 13: Rep. Michelle Lujan Grisham (D-NM) speaks during a news conference on immigration to condemn the Trump Administration's "zero tolerance" immigration policy, outside the US Capitol on June 13, 2018 in Washington, DC. (Photo by Toya Sarno Jordan/Getty Images)
Now playing
02:39
Governor settles with former campaign staffer who accused her of sexual mistreatment
Former Minneapolis Police officer Derek Chauvin chooses not to testify at his trial on April 15. Sitting to his left is defense attorney Eric Nelson.
Pool
Former Minneapolis Police officer Derek Chauvin chooses not to testify at his trial on April 15. Sitting to his left is defense attorney Eric Nelson.
Now playing
02:10
Derek Chauvin invokes 5th Amendment right at trial
Rep. Matt Gaetz, R-Fla., questions witnesses during a House Armed Services Committee hearing on Capitol Hill, Wednesday, April 14, 2021, in Washington.
Manuel Balce Ceneta/AP
Rep. Matt Gaetz, R-Fla., questions witnesses during a House Armed Services Committee hearing on Capitol Hill, Wednesday, April 14, 2021, in Washington.
Now playing
02:59
Women detail late-night parties with Gaetz
Pool
Now playing
06:07
Fauci fires back at Rep. Jim Jordan during heated exchange
President Joe Biden arrives to speak from the Treaty Room in the White House on Wednesday, April 14, 2021, about the withdrawal of the remainder of U.S. troops from Afghanistan.
Andrew Harnik/Pool/AP
President Joe Biden arrives to speak from the Treaty Room in the White House on Wednesday, April 14, 2021, about the withdrawal of the remainder of U.S. troops from Afghanistan.
Now playing
02:44
See Biden make historic announcement on US troops in Afghanistan
Avril Haines
POOL
Avril Haines
Now playing
01:09
DNI director gives two primary theories of where Covid-19 transmitted initially
THE BACHELORETTE - Fan favorite Becca Kufrin captured America's heart when she found herself at the center of one of the most gut-wrenching Bachelor breakups of all time. Now the Minnesota girl next door returns for a second shot at love and gets to hand out the roses, searching for her happily-ever-after in the 14th edition of ABC's hit series "The Bachelorette," premiering MONDAY, MAY 28 (8:00-10:01 p.m. EDT), on The ABC Television Network. (ABC/Craig Sjodin)
COLTON
Craig Sjodin/ABC
THE BACHELORETTE - Fan favorite Becca Kufrin captured America's heart when she found herself at the center of one of the most gut-wrenching Bachelor breakups of all time. Now the Minnesota girl next door returns for a second shot at love and gets to hand out the roses, searching for her happily-ever-after in the 14th edition of ABC's hit series "The Bachelorette," premiering MONDAY, MAY 28 (8:00-10:01 p.m. EDT), on The ABC Television Network. (ABC/Craig Sjodin) COLTON
Now playing
01:24
Former 'Bachelor' star says he is gay
american airlines plane preparations summer travel muntean pkg vpx_00000000.png
american airlines plane preparations summer travel muntean pkg vpx_00000000.png
Now playing
03:10
American Airlines prepares for summer travel demand surge
Family Photo/Getty Images
Now playing
04:11
Former officer charged with 2nd-degree manslaughter in Daunte Wright killing
Pool
Now playing
03:02
Use-of-force expert says Chauvin's actions were 'justified'
CNN
Now playing
01:06
Dr. Gupta: Johnson & Johnson vaccine pause will fuel hesitancy
CNN
Now playing
02:02
Daunte Wright's mom emotionally recounts her son's death
Barbers from King's Cutz give haircuts indoors while observing COVID-19 safety restrictions on March 13, 2021 in Los Angeles, California.
Mario Tama/Getty Images
Barbers from King's Cutz give haircuts indoors while observing COVID-19 safety restrictions on March 13, 2021 in Los Angeles, California.
Now playing
01:43
US consumer prices increased in March
screengrab japan fukushima daiichi
IAEA
screengrab japan fukushima daiichi
Now playing
02:31
Japan plans to release treated Fukushima water into sea
BROOKLYN CENTER, MINNESOTA - APRIL 12: Demonstrators face off with police officers outside of the Brooklyn Center police station on April 12, 2021 in Brooklyn Center, Minnesota. People have taken to the streets to protest after Daunte Wright, a 20-year-old Black man, was shot and killed by Brooklyn Center police officer Kimberly Potter during a traffic stop yesterday.  (Photo by Scott Olson/Getty Images)
Scott Olson/Getty Images
BROOKLYN CENTER, MINNESOTA - APRIL 12: Demonstrators face off with police officers outside of the Brooklyn Center police station on April 12, 2021 in Brooklyn Center, Minnesota. People have taken to the streets to protest after Daunte Wright, a 20-year-old Black man, was shot and killed by Brooklyn Center police officer Kimberly Potter during a traffic stop yesterday. (Photo by Scott Olson/Getty Images)
Now playing
01:14
Protests break out over the shooting of Daunte Wright
Nikki Haley, the United States Ambassador to the United Nations looks on during a meeting with US President Donald Trump speaks in the Oval office of the White House October 9, 2018 in Washington, DC. - Nikki Haley resigned Tuesday as the US ambassador to the United Nations, in the latest departure from President Donald Trump's national security team. Meeting Haley in the Oval Office, Trump said that Haley had done a "fantastic job" and would leave at the end of the year. (Photo by Olivier Douliery / AFP) (Photo by OLIVIER DOULIERY/AFP via Getty Images)
Olivier Douliery/AFP/Getty Images
Nikki Haley, the United States Ambassador to the United Nations looks on during a meeting with US President Donald Trump speaks in the Oval office of the White House October 9, 2018 in Washington, DC. - Nikki Haley resigned Tuesday as the US ambassador to the United Nations, in the latest departure from President Donald Trump's national security team. Meeting Haley in the Oval Office, Trump said that Haley had done a "fantastic job" and would leave at the end of the year. (Photo by Olivier Douliery / AFP) (Photo by OLIVIER DOULIERY/AFP via Getty Images)
Now playing
01:48
Nikki Haley U-turns on 2024 presidential run. An analyst explains why

Story highlights

Global sea level is on the rise at an increasing rate, according to a new study

By the end of the century, it could rise another 2 feet

(CNN) —  

Sea level rise is happening now, and the rate at which it is rising is increasing every year, according to a study released Monday in the Proceedings of the National Academy of Sciences.

Researchers, led by University of Colorado-Boulder professor of aerospace engineering sciences Steve Nerem, used satellite data dating to 1993 to observe the levels of the world’s oceans.

Changes in sea level observed between 1992 and 2014. Orange/red colors represent higher sea levels, while blue colors show where sea levels are lower.
from NASA
Changes in sea level observed between 1992 and 2014. Orange/red colors represent higher sea levels, while blue colors show where sea levels are lower.

Using satellite data rather than tide-gauge data that is normally used to measure sea levels allows for more precise estimates of global sea level, since it provides measurements of the open ocean.

The team observed a total rise in the ocean of 7 centimeters (2.8 inches) in 25 years of data, which aligns with the generally accepted current rate of sea level rise of about 3 millimeters (0.1 inches) per year.

But that rate is not constant.

Continuous emissions of greenhouse gases are warming the Earth’s atmosphere and oceans and melting its ice, causing the rate of sea level rise to increase.

“This acceleration, driven mainly by accelerated melting in Greenland and Antarctica, has the potential to double the total sea level rise by 2100 as compared to projections that assume a constant rate, to more than 60 centimeters instead of about 30,” said Nerem, who is also a fellow with the Cooperative Institute for Research in Environmental Science.

Greenland’s melting glaciers may someday flood your city

That projection agrees perfectly with climate models used in the latest International Panel on Climate Change report, which show sea level rise to be between 52 and 98 centimeters by 2100 for a “business as usual” scenario (in which greenhouse emissions continue without reduction).

Therefore, scientists now have observed evidence validating climate model projections, as well as providing policy-makers with a “data-driven assessment of sea level change that does not depend on the climate models,” Nerem said.

Sea level rise of 65 centimeters, or roughly 2 feet, would cause significant problems for coastal cities around the world. Extreme water levels, such as high tides and surges from strong storms, would be made exponentially worse.

Consider the record set in Boston Harbor during January’s “bomb cyclone” or the inundation regularly experienced in Miami during the King tides; these are occurring with sea levels that have risen about a foot in the past 100 years.

Nerem provided this chart showing sea level projections to 2100 using the newly calculated acceleration rate.
Steve Nerem
Nerem provided this chart showing sea level projections to 2100 using the newly calculated acceleration rate.

Now, researchers say we could add another 2 feet by the end of this century.

Nerem and his team took into account natural changes in sea level thanks to cycles such as El Niño/La Niña and even events such as the 1991 eruption of Mount Pinatubo, which altered sea levels worldwide for several years.

The result is a “climate-change-driven” acceleration: the amount the sea levels are rising because of the warming caused by manmade global warming.

The researchers used data from other scientific missions such as GRACE, the Gravity Recovery and Climate Experiment, to determine what was causing the rate to accelerate.

NASA's GRACE mission used satellites to measure changes in ice mass. This image shows areas of Antarctica that gained or lost ice between 2002 and 2016.
NASA
NASA's GRACE mission used satellites to measure changes in ice mass. This image shows areas of Antarctica that gained or lost ice between 2002 and 2016.

Currently, over half of the observed rise is the result of “thermal expansion”: As ocean water warms, it expands, and sea levels rise. The rest of the rise is the result of melted ice in Greenland and Antarctica and mountain glaciers flowing into the oceans.

Theirs is a troubling finding when considering the recent rapid ice loss in the ice sheets.

“Sixty-five centimeters is probably on the low end for 2100,” Nerem said, “since it assumes the rate and acceleration we have seen over the last 25 years continues for the next 82 years.”

Join the conversation

  • Track the latest weather story and share your comments with CNN Weather on Facebook and Twitter.

“We are already seeing signs of ice sheet instability in Greenland and Antarctica, so if they experience rapid changes, then we would likely see more than 65 centimeters of sea level rise by 2100.”

Penn State climate scientist Michael Mann, who was not involved with the study, said “it confirms what we have long feared: that the sooner-than-expected ice loss from the west Antarctic and Greenland ice sheets is leading to acceleration in sea level rise sooner than was projected.”

CNN’s Judson Jones contributed to this story.