New paper finds sea level rise has decelerated 44% since 2004 to only 7 inches per century

A paper published today in Global and Planetary Change finds global sea level rise has decelerated by 44% since 2004 to a rate equivalent to only 7 inches per century. According to the authors, global mean sea level rise from 1993-2003 was at the rate of 3.2 mm/yr, but sea level rise "started decelerating since 2004 to a rate of 1.8 ± 0.9 mm/yr in 2012."

The authors also find "This deceleration is mainly due to the slowdown of ocean thermal expansion in the Pacific during last decade," which is in direct opposition to claims that the oceans "ate the global warming." This finding debunks alarmist claims that ocean heat uptake has increased over the past decade, demonstrating instead that ocean heat uptake has decreased during the global warming pause since 2004, and has gone negative since 2007, as shown by fig. 4b indicating steric sea level rise from thermal expansion has been negative since 2007. 

The paper adds to several other peer-reviewed publications finding either no acceleration or a deceleration of sea level rise during the 20th and 21st century, and thus no evidence of any human influence on sea level rise:

JM Gregory et al Journal of Climate 2012
M Beenstock et al 2013
NOAA 2005-2012 Sea Level Budget
Dean & Houston 2011 & 2013
Scafetta 2013
Holgate 2007
Boretti 2012
Morner 2004
Jevrejeva et al., 2006 & 2008
Wöppelmann et al., 2009
Roemmich et al 2013

IPCC 2007:
"no long-term acceleration of sea level has been identified using 20th-century data alone."

IPCC 2013:
"It is likely that GMSL [Global Mean Sea Level] rose between 1920 and 1950 at a rate comparable to that observed between 1993 and 2010"

Figures from the paper & abstract:

Fig. 2. 

The instantaneous rate of interannual variability of (a) the GMSL, (b) the global mean steric sea level, and (c) the global mean ocean mass, i.e. the first-order time derivative of third IMFs shown in Fig. 1.

Fig. 3. 

a. Regression of total sea level (observed by altimeters) during 1993-2012 on the third IMF of the GMSL given in Fig. 1a.

b. Same as Fig. 3a but for the steric sea level.

Fig. 4. 

a. The intrinsic trend of the GMSL, i.e. the first-order time-derivative of the trend function of the GMSL given in Fig. 1a. Thick solid black line denotes the mean intrinsic trend of all the sub-samples of the GMSL during 1993-2012. Thin solid black line gives the linear trend of the GMSL rise, and the thin dashed lines give its one standard deviation.

b. Same as Fig. 4a but for the intrinsic trend of the global mean steric sea level.

c. Same as Fig. 4a but for the intrinsic trend of the global mean ocean mass during 2003-2012.

Fig. 5. 

a. Mean trend of the total sea level rise during (top) Period 1 (1993-2003) and (bottom) Period 2 (2004-2012).

b. Same as Fig. 5a but for the steric sea level.

Fig. 1. 

a. The global mean sea level (GMSL) with the ending date changing from 1 to 24 months earlier relative to December 2012 (bottom panel, thin lines end with the color from red to yellow). The IMFs of each time series, corresponding to the high-frequency noise, the annual cycle, the interannual variability, and the trend function (see text), are given as the colored lines in the panels from top to bottom, respectively. The ensemble mean of the IMFs on the different time scales during 1993-2010 are given as the thick black solid line in each panel. The colored bar in the third panel is the normalized Nino 3.4 index with arbitrary amplitude. The statistical confidence interval of the trend function is given by gray shadow in the bottom panel. The data is in units of cm.

b. Same as Fig. 1a but for the global mean steric sea level.

c. Same as Fig. 1a but for the global mean ocean mass during the period from January 2003 to December 2012.

Global Sea Level Trend during 1993-2012

• Xianyao Chen^a, b, , , 


• Ying Feng^a, b, 


• Norden E. Huang^a, b

• ^a Key Laboratory of Data Analysis and Applications, State Oceanic Administration, China


• ^b The First Institute of Oceanography, State Oceanic Administration, China

Highlights

•

The global mean sea level started decelerated rising since 2004 with the rising rate 1.8 ± 0.9 mm/yr in 2012.

•

Deceleration is due to slowdown of ocean thermal expansion during last decade.

•

Recent ENSO events introduce large uncertainty of long-term trend estimation.

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Abstract

Projection of future sea level change relies on the understanding of present sea-level trend and how it has varied in the past. Here we investigate the global-mean sea level (GMSL) change during 1993-2012 using Empirical Mode Decomposition, in an attempt to distinguish the trend over this period from the internannual variability. It is found that the GMSL [Global Mean Sea Level] rises with the rate of 3.2 ± 0.4 mm/yr during 1993-2003 and started decelerating since 2004 to a rate of 1.8 ± 0.9 mm/yr in 2012. This deceleration is mainly due to the slowdown of ocean thermal expansion in the Pacific during last decade, as a part of the Pacific decadal-scale variability, while the land-ice melting is accelerating the rise of the global ocean mass-equivalent sea level. Recent rapid recovery of the rising GMSL from its dramatic drop during the 2011 La Niña introduced a large uncertainty in the estimation of the sea level trend, but the decelerated rise of the GMSL [Global Mean Sea Level]  appears to be intact.