How much will global sea level rise this century?
How much will global sea level rise this century? Well, global sea level rise began in the late 1700s, and accelerated to 1.2 inches (3 cm) per decade over the past 25 years (see my post, Sea level rise: what has happened so far). If the conditions that led to this acceleration continue, we can expect sea level will rise an additional 1.1 ft (0.34 m) by 2100 (Jevrejeva et al., 2008). At a minimum, sea level rise during the 21st century should equal that of the 20th century, about seven inches (0.6 ft, 0.18 meters). This is the lower bound given by the IPCC in its 2007 assessment, which projected sea level rise of 0.6 - 1.9 ft (0.18 - 0.59 m) by 2100. However, they cautioned in their report that due to the lack of knowledge about how melting glaciers behave, the actual sea level rise might be higher. There is a growing consensus that the 2007 IPCC sea level rise estimates are much too low.
Figure 1. Observed global sea level from tide gauges (red line, pink color is the uncertainty range) and satellite measurements (green line), with forecasts for the future. The blue colors show the range of projections for three different forecasts (the forecasts overlap, but this overlap is not shown). Image modified from U.S. EPA.
The 2007 IPCC report: too conservative?
Three major sea level rise studies published since the 2007 IPCC report have argued that the IPCC's projections of sea level rise are too conservative. A paper published in 2008 in Science by Pfeffer et al. (2008) concluded that the "most likely" range of sea level rise by 2100 is 2.6 - 6.6 ft (0.8 - 2.0 meters). Their estimates came from a detailed analysis of the processes the IPCC said were understood too poorly to model--the ice flow dynamics of glaciers in Greenland and Antarctica. For example, increased glacial flow may result when water draining from melt water lakes on the surface of the glacier to the base of the glacier, where it acts as a lubricant. The authors cautioned that "substantial uncertainties" exist in their estimates, and that the cost of building higher levees to protect against sea level rise is not trivial.
Stefan Rahmstorf of the Potsdam Institute for Climate Impact Research in Germany looked at the observed relationship between changes in sea level and global temperatures since 1900 (Rahmstorf, 2007). Rahmstorf showed that that there has been a direct relationship between sea level rise and global average temperature: 0.1 - 0.3 meters of sea level rise occurs per °C increase in global temperature. Using this relationship, Rahmstorf predicted 1.6 - 4.6 ft (0.5 - 1.4 m) of sea level rise by 2100, since the IPCC predicts that global temperatures will rise 1.4° to 5.8°C. Rahmstorf concluded, "very low sea-level rise values as reported in the 2007 IPCC report now appear rather implausible in the light of the observational data".
A similar approach was taken by Grinsted et al. (2009), but they extended the relationship between sea level and global average temperature all the way back to 200 A.D. using proxy records. They concluded that ice sheets respond more quickly to temperature changes than the computer models used in the 2007 IPCC assessment. The authors estimated that "IPCC projections of sea level rise 2090 - 2099 are underestimated by roughly a factor of three". The authors predicted that global sea level will be rising 11 mm/year by 2050--four times faster than the 20th century rise. By the last decade of this century, they forecasted that sea level will rise 3.0 - 4.3 feet (0.9 - 1.3 meters), using the IPCC's A1B "business as usual" scenario.
The long-range forecast: using paleohistory to forecast sea level rise
We can also look at times in Earth's past that had similar climate to what we expect by the year 2100. The best time to look at is probably just before the most recent ice age--the Eemian. This interglacial period 130,000 - 114,000 years ago featured temperatures near the poles that were 2°C warmer than present-day temperatures. Tree line lay about 500 miles farther north in the Canadian Arctic, and the hippopotamus ranged as far north as the Thames River in England. A similar climate is expected under some of the more moderate global warming scenarios envisioned by the IPCC. Sea level is believed to have been 4 - 6 meters (13 - 20 feet) higher than at present during the Eemian, but there is at least one unpublished study that presents evidence that global sea level was 6 - 9 meters (20 - 30 feet) higher. If the climate does warm to levels seen in the Eemian, it is widely believed that we would again see sea levels at least 4 - 6 meters higher than the present-day levels. Clearly, sea level rises of this magnitude would be ruinous to society. However, most climate change scientists believe that it would take many centuries for enough ice to melt from the Greenland and West Antarctic ice sheets to create sea level rises of 4 - 6 meters.
However, the scientist who is arguably the most visible and authoritative climate scientist in the world, Dr. James Hansen of NASA, stated (Hansen, 2007) "I find it almost inconceivable that business-as-usual climate change would not yield a sea level change of the order of meters on the century timescale" (IPCC business-as-usual (BAU) scenarios assume that emissions of CO2 and other greenhouse gases will continue to increase year after year). Hansen gave a hypothetical but potentially realistic scenario where the sea level rise due to ice sheet disintegration doubles every decade, leading to a 16 foot (5 meter) sea level increase by 2100. He noted that during the Plio-Pleistocene period 2 - 3 million years ago, CO2 levels were similar to today (350 - 450 ppm), and global temperatures were 2 - 3°C warmer, similar to what we expect by the end of the century. Yet, this Plio-Pleistocene world was "a dramatically different planet, without Arctic sea ice in the warm seasons and with a sea level 25 ± 10 m higher."
Summary
To summarize, here are some predictions of how high global sea level might rise by 2100:
0.6 ft (0.18 m): Constant linear rise, equal to 20th century rise
1.1 ft (0.34 m): Constant acceleration model (Jevrejeva et al., 2008)
0.6 - 1.9 ft (0.18 - 0.59 m): Primitive models of ice sheets (IPCC, 2007)
1.6 - 4.6 ft (0.5 - 1.4 m): Relationship between temperature and sea level rise since 1900 (Rahmstorf, 2007)
3.0 - 4.3 feet (0.9 - 1.3 m): Relationship between temperature and sea level rise since 200 A.D. (Grinsted et al., 2009)
2.6 - 6.6 ft (0.8 - 2.0 meters): Considering glacier ice flow dynamics not included by the IPCC (Pfeffer et al., 2008)
In a 2009 interview with New Scientist magazine, sea level expert Stephan Rahmstorf said, "I sense that now a majority of sea level experts would agree with me that the IPCC projections are much too low." This sentiment was echoed by glaciologist Robert Bindschadler of the NASA Goddard Space Flight Center in Greenbelt, Maryland, who commented, "most of my community is comfortable expecting at least a metre by the end of this century."
In forthcoming posts in this series, I'll explore how a meter (3.28 feet) of sea level rise will affect the U.S. coast, the Caribbean, and other vulnerable locations world-wide. It would be wise to begin preparing now for a potential rise in sea level of a meter this century. In particular, development near the coasts should be severely restricted in low-elevation zones. It will be very expensive to protect or move infrastructure away from rising seas later this century. However, even if the rate of sea level rise doubles every decade, those of us who are over the age of 50 will not live to see sea level rise cause a significant disruption to society. There is time for society to prepare for the rising sea.
References
Jevrejeva, S., J.C. Moore, A. Grinsted,, and P.L. Woodworth, 2008, "Recent global sea level acceleration started over 200 years ago?", Geophysical Research Letters, 35, L08715, doi:10.1029/2008GL033611, 2008.
Grinsted, A., J.C. Moore, and S. Jevrejeva, 2009, "Reconstructing sea level from paleo and projected temperatures 200 to 2100 AD", Climate Dynamics, DOI 10.1007/s00382-008-0507-2, 06 January 2009.
Hansen, J., 2007, "Scientific reticence and sea level rise",, Environ. Res. Lett. 2 (April-June 2007) 024002 doi:10.1088/1748-9326/2/2/024002.
IPCC (Intergovernmental Panel on Climate Change), 2007: Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change [Solomon, S., D. Qin, M. Manning, Z. Chen, M. Marquis, K.B. Averyt, M. Tignor, and H.L. Miller (eds.)]. Cambridge University Press, Cambridge, UK, and New York, 996 pp.
Pfeffer, W.T., J.T. Harper, and S. O'Neel, 2008, "Kinematic Constraints on Glacier Contributions to 21st-Century Sea-Level Rise", Science 321 no. 5894, pp. 1340-1343, 5 September 2008. DOI: 10.1126/science.1159099
Rahmstorf, Stefan. "Sea-Level Rise: A Semi-Empirical Approach to Projecting Future." Science 315 (2007): 368–370.
Other posts in this series
Sea level rise: what has happened so far
U.S. vulnerability to sea level rise
Wednesday, I'll take a look at the Atlantic hurricane forecast for the remainder of July. There's currently nothing out there worth discussing--will it stay that way?
Dr. Ricky Rood has some interesting commentary on the new climate change legislation that passed the House last month, and will go to the Senate in September.
Jeff Masters
Reader Comments
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Link
Reflector site for those at work, which includes Weather456, daily updates
AOI
AOI
"ON SATURDAY...A FAIRLY STRONG COOL FRONT WILL THEN MOVE ACROSS THE
AREA WHICH WILL EXTEND THE THREAT OF STRONG THUNDERSTORMS AT LEAST
THROUGH THE AFTERNOON HOURS. NORMALLY...FRONTS DON`T REMAIN THIS
ACTIVE THIS TIME OF THE YEAR. HOWEVER...WITH THIS TROF
PATTERN...THERE SHOULD NOT BE ANY PROBLEMS IN PUSHING THIS FRONT
ACROSS THE ENTIRE STATE.
LONG RANGE MODELS (GFS AND ECMWF) HAVE BEEN FAIRLY CONSISTENT IN
BRINGING A DRIER PATTERN EARLY NEXT WEEK. IN FACT...MOS GUIDANCE
IS COMING IN WITH WELL BELOW NORMAL TEMPERATURES BEGINNING ON
SUNDAY. MOS MAY BE HAVING A LITTLE BIT OF A HARD TIME HANDLING
THIS UNSEASONABLY COOL AIRMASS. AS A RESULT...WENT A LITTLE WARMER
THAN MOS DURING THAT PERIOD. STILL...IT WILL BE FAIRLY NICE SEEING
THESE KINDS OF TEMPERATURES IN JULY."
Climate change is just that people. "CHANGE". Why do certain scientists want to "predict" on something that has a documented history of changing? I for one don't buy into the fact that global warming is irreversable.
It's the Sun stupid. The Sun is what causes climate change and for man to think otherwise is more than arrogant.
The Earth is approximately 4.5 billion years old and we've been keeping temperature records (poorly I may add) for only 200 years. We're missing a large portion of the data set aren't we?
Get real people....
"FOR SAT INTO TUE...THE UPPER TROUGH WILL EVOLVE AND DEEPEN OVER THE
REGION. MODELS ARE IN GOOD AGREEMENT ON THIS EVOLUTION AND CARVE OUT
A ANOMALOUS TROUGH WITH MID LEVEL HGHTS REACHING SOME 2 TO 3.5
STANDARD DEVIATIONS BELOW CLIMO VALUES. IN ADDITION...SUCH A SYSTEM
WILL PULL DOWN COOLER LOW LEVEL TEMPS AND THE GFS/EURO ARE
ADVERTISING 850MB TEMPS IN THE 13-15C RANGE. THAT IS ALSO SOME 2 TO
3.5 STANDARD DEVIATIONS BELOW CLIMO VALUES. FITTING ENOUGH...THE 00Z
MEX GUID HAS 60-65 DEGREES FORECASTED FOR LOWS MON MORNING. I TOOK A
LOOK AND THE NUMBERS IT HAS WOULD SET A FEW RECORD LOWS. ONE THING I
HAVE LEARNED IS NOT TO FORECAST BELOW RECORD LOWS OUT IN THE
EXTENDED. SO...I HAVE TWEAKED SOME OF THE TEMPS MON MORNING UPWARD A
TAD. EITHER WAY...COOLER CONDITIONS LOOK TO DEVELOP SUN INTO TUE."
".LONG TERM...
WEDNESDAY LOOKS TO BE MORE LIKE A TYPICAL SUMMER TIME TSRM DAY BUT
WITH SLIGHTLY HIGHER COVERAGE. ABUNDANT MOISTURE WILL PERSIST WHICH
WILL AIDE IN CONVECTION DEVELOPMENT. HAVE POP GRADIENT ORIENTED W TO
E BASED ON EXPECTED SEA BREEZE NORTHWARD EXTEND. SO...COULD HAVE A
SLIGHTLY FARTHER NORTH OR SOUTH LINE OF HIGHER COVERAGE. TEMPS TO
CONTINUE RIGHT AT OR JUST ABOVE CLIMO.
UPPER TROUGH IN CANADA WILL BEGIN DIGGING SOUTHWARD INTO THE HIGH
CENTRAL PLAINS WED AFTERNOON AND CONTINUE SOUTHEASTWARD AS THE UPPER
RIDGE CURRENTLY OVER THE AREA SLIDES BACK WESTWARD. STILL A SLIGHT
DIFFERENCE IN FRONTAL TIMING BETWEEN MODELS BUT STILL SATISFIED WITH
OVERALL AGREEMENT. WIDESPREAD DEVELOPMENT SHOULD OCCUR ACROSS THE
AREA FRIDAY AHEAD OF THE BOUNDARY WHICH SHOULD BE MOVING THROUGH
CENTRAL MISSISSIPPI BY THE LATE AFTERNOON TO EVENING HRS. MODELS
STILL BRING THE FRONT INTO THE NORTHERN GULF BY SUNDAY MORNING. FROM
THIS TIME THROUGH THE END OF THE FORECAST...SHWR AND TSTM
DEVELOPMENT SHOULD BE MORESO TOWARDS THE COAST BUT STILL WITH SOME
ACTIVITY AS FAR NORTH AS MCB. TEMPS WILL REMAIN ON THE RELATIVELY
COOL SIDE THROUGH THE WEEKEND WITH HIGHS NEAR 90 TO THE UPPER 80S
AND LOWS APPROACHING THE UPPER 60S."
When Florida got hit multiple times in 2004, Jacksonville seemed like a lucky penny and practically the only patch of the state not hit by Tropical Storm force winds.
Link
From the 8 AM Discussion:
...DISCUSSION...
GULF OF MEXICO...
AN UPPER LEVEL RIDGE EXTENDS SOUTHEASTWARD INTO THE GULF OF MEXICO AND IS ASSOCIATED WITH A SURFACE RIDGE ALONG 26N AND A 1018 MB SURFACE HIGH NEAR 25N84W. GENERALLY FAIR WEATHER IS PRESENT ACROSS THE GULF. ONE EXCEPTION IS OVER THE N CENTRAL GULF...WHERE SCATTERED SHOWERS AND THUNDERSTORMS ARE PRESENT N OF 28N BETWEEN 87W-90W. THIS ACTIVITY IS BEING SUPPORTED BY ATMOSPHERIC LIFT ASSOCIATED WITH A WEAK SHORTWAVE TRANSLATING SOUTHEASTWARD ON THE OUTER PERIPHERY OF THE AFOREMENTIONED UPPER RIDGE. WINDS ARE LIGHT AND VARIABLE IN THE VICINITY OF THE SURFACE RIDGE ACROSS THE N GULF...WITH ANTICYCLONIC FLOW AROUND THE RIDGE SUPPORTING A BROAD SWATH OF E WINDS OF 10-15 KT ACROSS
THE S HALF OF THE GULF. LITTLE CHANGE IS EXPECTED OVER THE NEXT DAY OR TWO AS BOTH THE UPPER AND SFC RIDGE REMAIN IN PLACE.
If there was one place in Florida I thought was safe from a major hit, it's Jacksonville,Fl.
Here's my forecast for next Monday...
"Monday: A 40 percent chance of showers and thunderstorms. Mostly cloudy, with a high near 86."....
What is this, fall? LOL....do I need to start raking leaves?
Cool Side??? Not for NE though, hehe
Yes, summer has been cancelled.
True
Maybe from Insurance standards, but they have been lucky like TWC says it can happen tomorrow!
A cold front into the GOM in July...
Nashville,TN. extended.....home of the Grand Ole Opry....
"A RATHER STRONG AND COOL SFC RIDGE SETTLES SEWD OVER THE TENNESSEE
VALLEY OVER THE WEEKEND BRINGING MUCH COOLER AIR WITH IT. 850MB TEMPS
ARE EXPECTED TO DROP FROM THE CURRENT 20C TO AROUND 9C BY SUN AM.
THIS SHOULD DROP AFTERNOON HIGH TEMPS INTO THE LOWER 80S FOR THE
WEEKEND...ABOUT 7-8F BELOW NORMAL."
Click on image for loop.
13N 35W on the Atlantic Wide View visible loop
Any one else agree.
But no, hurricanes don't tend to go over that way. Georgia hasn't been hit by a big one for a while, either. Over a 100 years ago I think (though David did go up that way, just wasn't a major when it went to GA. Cat 2s can be bad enough.)
Despite that, records are there to be broken.
The Atl. remains relatively quiet today and there has been no additional organization of the CATL wave. In fact, the quikscat pass shows a deterioration in the definition of the surface low we saw in the pass last night.
It would appear that the feature is dividing into two seperate features moving in different directions. There is a mid level spin near 13N 35W that is moving in a general NW motion and a seperate mid level spin near 8N 44W that is moving due W.
For now it looks like slow going out there.
AVN Loop showing separate areas of interest
I agree with you
Link
Ike if this trend continues though anything in the Caribbean might also get pulled Northward like Charley in O4 so something to keep watching.
Glad the police caught that guy in Oklaloosa County.
The gfs basically drops in after T=72
The ngp just ignores it all
???
check your WU mail:) with the answer.
Yeah...okay...I saw the headline on the NWFDN website...didn't read the story though....
78.8 degrees outside my house...right now....
Our wave at 35W showing some very nice structure this morning.Still in bed with the ITCZ at this point. Gentle upper level out flow under an upper high and very visible turning at the mid-levels. Certainly does not seem like this thing will just dissapear anyway. The forecasted trough and associated low over the NE US does not look very progressive-hanging and deepening over the eastern half of the country for a few days. A 3 or 4 day period to erode the A/B ridge as the wave approaches the islands-making a track into the Caribbean less likely?
All speculation-but at least some support from the GFS for this scenario.
Taz, I think 96E is already a depression, and should be classified at 11:00. Did you see tiny Carlos is a hurricane again?
000
WHXX01 KMIA 141256
CHGE77
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1256 UTC TUE JUL 14 2009
DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.
EAST PACIFIC OBJECTIVE AIDS FOR
TROPICAL CYCLONE CARLOS (EP042009) 20090714 1200 UTC
...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090714 1200 090715 0000 090715 1200 090716 0000
LAT LON LAT LON LAT LON LAT LON
BAMS 9.9N 127.3W 10.0N 129.3W 10.2N 131.5W 10.5N 133.8W
BAMD 9.9N 127.3W 10.0N 128.9W 10.1N 130.4W 10.2N 132.0W
BAMM 9.9N 127.3W 10.0N 128.9W 10.2N 130.6W 10.4N 132.4W
LBAR 9.9N 127.3W 10.0N 128.6W 10.5N 130.0W 11.0N 131.5W
SHIP 75KTS 79KTS 77KTS 73KTS
DSHP 75KTS 79KTS 77KTS 73KTS
...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090716 1200 090717 1200 090718 1200 090719 1200
LAT LON LAT LON LAT LON LAT LON
BAMS 10.8N 136.3W 10.8N 142.1W 10.8N 149.5W 11.0N 157.5W
BAMD 10.2N 133.8W 9.8N 138.1W 9.1N 143.1W 8.1N 148.8W
BAMM 10.5N 134.3W 10.4N 138.8W 10.0N 144.1W 9.5N 150.2W
LBAR 11.4N 132.9W 11.7N 136.6W 12.1N 141.5W 11.5N 147.2W
SHIP 69KTS 59KTS 53KTS 43KTS
DSHP 69KTS 59KTS 53KTS 43KTS
...INITIAL CONDITIONS...
LATCUR = 9.9N LONCUR = 127.3W DIRCUR = 280DEG SPDCUR = 6KT
LATM12 = 9.6N LONM12 = 126.2W DIRM12 = 275DEG SPDM12 = 6KT
LATM24 = 9.7N LONM24 = 124.7W
WNDCUR = 75KT RMAXWD = 10NM WNDM12 = 55KT
CENPRS = 981MB OUTPRS = 1007MB OUTRAD = 125NM SDEPTH = D
RD34NE = 40NM RD34SE = 30NM RD34SW = 30NM RD34NW = 40NM
$$
yup what you think about per 97E that i showed you looks like it has a good shot at it has well
Carlos continues to strengthen. They are going to up the winds from 75 mph to 85 mph at next advisory. Now it would not shock me if Carlos got to Category 2 strength
THE CENTER...AND TROPICAL STORM FORCE WINDS EXTEND OUTWARD UP TO 35
MILES...55 KM.
Talk about small. That is tiny!
That is actually a great comment; in spite of the excitement and awe associated with watching/tracking these storms, a "great" season is one with very few landfalling hurricanes......A slow season is the best case scenario for everyone concerned in the Caribbean/Central America/US.
"In the last century, sea level rose 5 - 6 inches (13 - 15 cm) more than the global average of 7 inches (18 cm) along the U.S. Mid-Atlantic and Gulf Coasts, because coastal lands there are sinking. "
First...How does sea level rise more in one place on the planet than another? Answer...It doesn't.
Second...Is this the sad level to which climatology has descended that a land mass sinking equates to sea level rise?
Third...Is it so important to support man-made global warming that it is okay to stoop so low? Absolutely not!!
Man-made global warming is nothing more than a poorly veiled grab for huge amounts of money.
How else could a person accept the premise that a land mass sinking into the sea and the water naturally moving into those lowered areas...equates with a rise in sea level.
Sounds like the flat earthers of centuries ago. Sans circumnavigating the world, scientists concluded the earth was flat and those with differing opinions were labeled as heretics. Those scientists had an excuse for their ignorance. How could they possibly know if a land mass had sunk into the sea of if the sea level was rising. With their frame of reference, they couldn't.
Time to turn off our TV's and i-Pods and computers...time to wake up. Man-made global warming is not about the weather...it is about huge taxation.
Can we please just talk about the weather that is happening today and how it will affect our immediate plans. Can we please just talk about the weather a few days from now and leave the political hysterics of global warming outside where it belongs.
BTW...Anyone care to guess the author of the opening quote?
Jeff Masters
may be
"First...How does sea level rise more in one place on the planet than another? Answer...It doesn't."
Read the statement before you make a comment.
The previous comment you made proves that you did not.. or at least you did not understand it.
"In the last century, sea level rose 5 - 6 inches (13 - 15 cm) more than the global average of 7 inches (18 cm) along the U.S. Mid-Atlantic and Gulf Coasts, because coastal lands there are sinking. "
Great update.
Double trouble?
G'morning, all.
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