Revisiting the Earth's sea-level and energy budgets from 1961 to 2008

Abstract

[1] We review the sea-level and energy budgets together from 1961, using recent and updated estimates of all terms. From 1972 to 2008, the observed sea-level rise (1.8 ± 0.2 mm yr −1 from tide gauges alone and 2.1 ± 0.2 mm yr −1 from a combination of tide gauges and altimeter observations) agrees well with the sum of contributions (1.8 ± 0.4 mm yr −1 ) in magnitude and with both having similar increases in the rate of rise during the period. The largest contributions come from ocean thermal expansion (0.8 mm yr −1 ) and the melting of glaciers and ice caps (0.7 mm yr −1 ), with Greenland and Antarctica contributing about 0.4 mm yr −1 . The cryospheric contributions increase through the period (particularly in the 1990s) but the thermosteric contribution increases less rapidly. We include an improved estimate of aquifer depletion (0.3 mm yr −1 ), partially offsetting the retention of water in dams and giving a total terrestrial storage contribution of −0.1 mm yr −1 . Ocean warming (90% of the total of the Earth's energy increase) continues through to the end of the record, in agreement with continued greenhouse gas forcing. The aerosol forcing, inferred as a residual in the atmospheric energy balance, is estimated as −0.8 ± 0.4 W m −2 for the 1980s and early 1990s. It increases in the late 1990s, as is required for consistency with little surface warming over the last decade. This increase is likely at least partially related to substantial increases in aerosol emissions from developing nations and moderate volcanic activity. Citation: Church, J. A.,

Bidecadal Thermal Changes in the Abyssal Ocean

“…If the heating were confined to the upper 700 m, then based on a mean ocean depth of about 3700 m the temperature change is increased to about 0.28C, and if all were confined to the region below that depth, the temperature change would be about 0.058C (see Table 1). Recent observationally based estimates (Church et al 2011) produce estimates closer to 0.5 W m 22 , exacerbating the detection problem. (That the atmospheric radiation budget includes such poorly determined elements as changes in aerosols and cloud distributions is a major impetus to determining actual ocean heat storage changes.)…”

Recent Progress in Understanding and Projecting Regional and Global Mean Sea Level Change

“…[40]), but not all (e.g., [41,42]), reported a sharp spike in ocean heat uptake in the early 2000s followed by a slowing of the rate of heat uptake (and thus ocean thermal expansion). Since then, Abraham et al [43] published a major review on the evolving observing system, the reduction of XBT biases, and estimates of heat content and thermosteric sea level trends over different periods, generally confirming the AR5 assessment of trends since 1971 and 1993.…”

Global and regional surface cooling in a warming climate: a multi-model analysis

“…As discussed in the previous section, the ocean is the prime candidate for temporary uptake and storage of heat (e.g., Levitus et al 2005;Church et al 2011;Katsman and van Oldenborgh 2011;Meehl et al 2011Meehl et al , 2013Trenberth and Fasullo 2013;Kosaka and Xie 2013;England et al 2014). Table 2 shows that decadal trends in the upper ocean heat content (0-700m) coincide with decadal trends in the global surface temperature in all of the scenarios investigated, where the correlations between the two variables range between 0.31 and 0.56 for the different scenarios.…”

“…Note the different range in (a) compared to the other panels or, alternatively, a net gain of heat at TOA, conservation of heat implies that periods with non-positive trends in surface temperature can only occur in tandem with redistribution of heat within the atmosphere-cryosphere-land-ocean system. Of these components, the ocean is by far the largest, dynamically active reservoir of heat (e.g., Charney et al 1979;Levitus et al 2005;Church et al 2011;Katsman and van Oldenborgh 2011).…”