A Reconciled Estimate of Glacier Contributions to Sea Level Rise: 2003 to 2009

Abstract

A reconciled estimate of glacier contributions to sea level rise: 2003 to 2009Gardner, Alex S; Bolch, Tobias; et al Abstract: Glaciers distinct from the Greenland and Antarctic Ice Sheets are losing large amounts of water to the world's oceans. However, estimates of their contribution to sea level rise disagree. We provide a consensus estimate by standardizing existing, and creating new, mass-budget estimates from satellite gravimetry and altimetry and from local glaciological records. In many regions, local measurements are more negative than satellite-based estimates. All regions lost mass during [2003][2004][2005][2006][2007][2008][2009], with the largest losses from Arctic Canada, Alaska, coastal Greenland, the southern Andes, and high-mountain Asia, but there was little loss from glaciers in Antarctica. Over this period, the global mass budget was -259 T 28 gigatons per year, equivalent to the combined loss from both ice sheets and accounting for 29 T 13% of the observed sea level rise.

Spatiotemporal patterns of High Mountain Asia's snowmelt season identified with an automated snowmelt detection algorithm, 1987–2016

“…This important water reserve is certain to be impacted by, and reflect changes in, the snowmelt regime of HMA, as the timing of precipitation has been shown to be an important factor in the response of glaciers to climate change (Maussion et al, 2014;Wang et al, 2017). While many regions have seen rapid glacier retreat (Bolch et al, 2012;Kääb et al, 2012Kääb et al, , 2015Scherler et al, 2011), there exist regions of glacier stability and even growth, such as the Karakoram (Hewitt, 2005;Gardelle et al, 2012) and Kunlun Shan (Gardner et al, 2013;Yao et al, 2012). Our results (see Fig.…”

“…1, inset). The interaction of these climatic regimes with the complex topography of HMA -particularly the vast elevation gradients -creates a diverse set of snowfall regimes (Cannon et al, 2014;Kääb et al, 2012;Immerzeel and Bierkens, 2012;Gardner et al, 2013;Kapnick et al, 2014;Barnett et al, 2005;Dahe et al, 2006;Takala et al, 2011;Cannon et al, 2017).…”

Glacier changes on the Tibetan Plateau derived from Landsat imagery: mid-1970s – 2000–13

“…Nearly all mountain glaciers have been melting rapidly in recent decades (Gardner and others, 2013; Zemp and others, 2015) and this has been documented, especially in High Mountain Asia (HMA hereafter), in surveys of the whole ( Li and others, 2008;Cogley, 2016) or large parts (Bolch and others, 2012;Yao and others, 2012) of the region as well as in basin-scale and single-glacier studies (Fujita and Nuimura, 2011;Wang and others, 2013;Yang and others, 2013). As reported in these earlier studies, most HMA glaciers showed obvious shrinkage (area loss) and thinning (implying mass loss) except in the west, for example in the Karakoram ( Gardelle and others, 2012) and western Kunlun (Neckel and others, 2014; Kääb and others, 2015; Ke and others, 2015).…”

Observation-Based Estimates of Global Glacier Mass Change and Its Contribution to Sea-Level Change

“…Some glacier parts are below sea level and, because of the ice/water density Table 2 Comparison of mass change estimates during common periods, in mm SLE year -1 and the 90% confidence interval, where given in the source (2002/2005-2013/2015) and adding the estimate for Greenland peripheral glaciers from Gardner et al (2013) difference, even cause a slight lowering of the sea level when replaced by water. Meltwater from glaciers on land may be held back in lakes, which form in over-deepened parts of glacier beds when becoming exposed.…”

“…The most recent global estimates of glacier mass changes include Jacob et al (2012) with 0.41 ± 0.08 mm SLE year -1 (2003-2010 time period) and Schrama et al (2014) with 0.45 ± 0.03 mm SLE year -1 (2003-2013) using the mascon-based approach, Chen et al (2013) with 0.54 ± 0.10 mm SLE year -1 (2005)(2006)(2007)(2008)(2009)(2010)(2011) and Yi et al (2015) with 0.58 ± 0.04 mm SLE year -1 (2005-2014) using the forward modeling-based method, and the four following studies which combined GRACE-based estimates with other datasets (e.g., altimetry, literature assessment, sea-level budget approach): Gardner et al (2013) with 0.60 ± 0.08 mm SLE year -1 (2003-2009), Dieng et al (2015) with 0.58 ± 0.1 mm SLE year -1 (2003-2013), Reager et al (2016), an update of Gardner et al (2013), with 0.53 ± 0.09 mm SLE year -1 (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014) and Rietbroek et al (2016) with 0.38 ± 0.07 mm SLE year -1 (2002)(2003)(2004)(2005)(2006)(2007)(2008)(2009)(2010)(2011)(2012)(2013)(2014). See Fig.…”