One of the major reasons for the large range in the projections of sea level rise (i.e., about 9 to 89 cm by 2100) that was included in IPCC’s Third Assessment Report was due to the uncertainty in the term related to terrestrial water storage, so just the subject of this letter. It was because this range was so large and got up near 1 m/century that the chapter went forward as there was significant criticism by US reviewers about the importance of having left out the potential contribution from the dynamic movement of ice sheets.
In the Fourth Assessment Report, I don’t think they included this term due to its significant uncertainty—and again they were not able to specifically include the effects of the dynamic movement of the ice sheets, and so they came out with a narrower and smaller numerical projection for sea level rise. So, interesting letter and estimate—I wonder how long it could continue (that is, how much water could be depleted from groundwater, etc.)? Mike On 5/26/12 4:20 AM, "Andrew Lockley" <[email protected]> wrote: > This interesting letter from nature geoscience shows that control of a > substantial fraction of sea level rise is beyond the control of > geoengineering, as it's anthropogenic in origin. > > We may therefore have to hit the SRM brakes harder and earlier than expected, > if we want to save the coastal cities > > I find SLR interesting, as we will have to wind back the climate clock to > control it. Stopping temperatures increasing won't stop glaciers melting. I > fear that's often overlooked by current estimates of the scale of intervention > needed. > > A > > Nature Geoscience | Letter > Model estimates of sea-level change due to anthropogenic impacts on > terrestrial water storage > Yadu N. Pokhrel, Naota Hanasaki, Pat J-F. Yeh, Tomohito J. Yamada, Shinjiro > Kanae & Taikan Oki > Affiliations > Contributions > Corresponding author > Nature Geoscience (2012) doi:10.1038/ngeo1476 > Received 25 October 2011 Accepted 17 April 2012 Published online 20 May 2012 > Article tools > Print > Email > Download citation > Order reprints > Rights and permissions > Share/bookmark > > Global sea level has been rising over the past half century, according to > tide-gauge data1, 2. Thermal expansion of oceans, melting of glaciers and loss > of the ice masses in Greenland and Antarctica are commonly considered as the > largest contributors, but these contributions do not entirely explain the > observed sea-level rise1. Changes in terrestrial water storage are also likely > to affect sea level3, 4, 5, 6, but comprehensive and reliable estimates of > this contribution, particularly through human water use, are scarce1. Here, we > estimate sea-level change in response to human impacts on terrestrial water > storage by using an integrated model that simulates global terrestrial water > stocks and flows (exclusive to Greenland and Antarctica) and especially > accounts for human activities such as reservoir operation and irrigation. We > find that, together, unsustainable groundwater use, artificial reservoir water > impoundment, climate-driven changes in terrestrial water storage and the loss > of water from closed basins have contributed a sea-level rise of about > 0.77 mm yr−1 between 1961 and 2003, about 42% of the observed sea-level rise. > We note that, of these components, the unsustainable use of groundwater > represents the largest contribution. -- You received this message because you are subscribed to the Google Groups "geoengineering" group. To post to this group, send email to [email protected]. To unsubscribe from this group, send email to [email protected]. For more options, visit this group at http://groups.google.com/group/geoengineering?hl=en.
