Weerwoord | Re : wat het WWF zegt en de bronnen

Het WWF schrijft:

The Arctic Ocean is losing sea ice 30 or more years ahead of the projections presented in the Fourth Assessment Report (Stroeve et al, 2007). There is near consensus in the Arctic scientific community that significant aspects of this hastened loss of sea ice are caused by feedback mechanisms, the effects of which had been severely underestimated in the report. For example, a reduction in sea ice has meant that ocean waters have been warmed more by the sun, making it even more difficult to form and to retain sea ice the next winter. Indeed prominent scientists are now saying that we are at – or have already passed – the tipping point for the Arctic sea ice system. This means that the Arctic Ocean could very soon be ice-free during the summer. It is currently forecast that summer sea ice could completely disappear somewhere between 2013 and 2040 – a state not seen on planet Earth for more than a million years. An ice-free Arctic Ocean during summer is expected to amplify global warming through the absorption of more heat by a dark ocean surface (instead of the white surface of sea ice) and changes in ocean circulation. This is likely to open the gates to climate change that is even more rapid and abrupt than has been forecast up to now (WWF 2008, SEARCH 2008).

Floating tide-water glaciers in the Antarctic Peninsula are losing ice faster and are making a greater contribution to global sea level rise than reported in the Fourth Assessment Report (Pritchard and Vaughan 2007).

Since 1990, global sea level has been rising one and a half times faster than forecast in the IPCC’s Third Assessment Report (published in 2001) (Rahmstorf et al 2007). In addition to this, new studies have projected global sea level rise by the end of the century to reach up to more than double the maximum estimate of 0.59m presented in the Fourth Assessment Report (Rahmstorf 2007, Rohling et al 2008). More than 1.2m sea level rise would put vast coastal areas at risk, in Europe and around the world.''

De referenties:

- Stroeve, J., Holland, M., Meir, W., Scambon, T. and Serreze, M. 2007. Arctic sea ice decline: faster than forecast. Geophysical Research Letters, 34, L09501, doi:10.1029/2007GL029703, download hier
- Pritchard, H.D. and Vaughan, D.G. 2007. Widespread acceleration of tidewater glaciers on the Antarctic Peninsula. Journal of Geophysical Research, 112, F03S29, doi:10.1029/2006JF000597, abstract hier
- Rahmstorf, S. 2007. A semi-empirical approach to projecting future sea-level rise. Science, 315(5810), 368-370, download hier
- Rohling, E.J., Grant, K., Hemleben, C., Siddall, M., Hoogakker, B.A.A., Bolshaw, M. and Kucera, M. 2008. High rates of sea-level rise during the last interglacial period. Nature Geoscience, 1, 38-42, download hier

Gr. Ben