Antarctica represents one of the most serious potential threats from rapid cryosphere warming at the global level. Along with northern hemisphere permafrost melt, the instability of the West Antarctic Ice Sheet (WAIS) may represent the largest risk of all to the human community and global environment – the IPCC Fifth Assessment could not rule out its collapse already during this century, and some studies of past climate change indicate a large risk of such an event occurring, even within (though barely) current temperature levels.
This could entail several additional decimeters of sea level rise already in this century, and 3-6 meters in the centuries after that. Or, the sheet could prove more stable and survive intact a global 2 degree peak in temperature – because of the nature of ice sheet collapse, we are unlikely to know the answer ahead of time. Although much research currently is focused on this issue, more intense observation of this region is badly needed.
That risk of collapse however is one reason to attempt to constrain temperature rise in West Antarctica as much as possible. Methane emissions present a clear target for doing so – as with the Arctic and most land areas, the climate benefits of cuts in methane emissions are somewhat larger on Antarctica than the global mean (see figure below). Can black carbon reductions however provide similar benefits?
Many scientists think not – that the strength of the Antarctica gyre is simply too strong to allow much ingress of pollutants originating elsewhere. Emissions from sources within and around the continent, even the burgeoning cruise tourism industry, are assumed too small to have much significance. At the same time, there are some reports of black carbon deposits in the region. Where might these originate, and are they at all similar in magnitude to deposits on Greenland or Arctic sea ice? Is the Antarctic Peninsula – the single place on earth with the most rapid rise in temperature – different in this regard, given its relative nearness to Patagonia, with its frequent forest fires; and the grassland fires of the pampas region? What research exists on this issue – including in Spanish and Russian, as well as by other major research stations and the 48 Antarctic Treaty nations with some scientific presence in the region?
The recently-completed “On Thin Ice” modeling contains some intriguing indications that black carbon sources may hold some promise for slowing warming over Antarctica. Surprisingly, the models showed a fair degree of impact from two black carbon sources in particular: cookstoves emissions (greater impact even than over the Arctic) and diesel emissions. In one of the models used, diesel impacts over the Antarctic Peninsula seemed related especially to the southern portion of the Andes and Patagonia, where diesel impacts were also large (see figure below).
Long-range Transport? (Diesel off-road, ECHAM model)
ICCI has joined the Antarctic and Southern Oceans Coalition (ASOC), the umbrella organization for civil society representation at meetings of the Antarctic Treaty system. In May 2013, ICCI participated in the Antarctic Treaty Consultative Meetings in Brussels, and presented an Information Paper on the issue of short-lived forcers, for the first time in ATCM history (click here for a copy). We have begun looking at potential local sources of black carbon emissions such as research stations, shipping and tourism; and are seeking support to engage a dedicated Antarctic Director, to intensify ICCI work with the research and policy community and clarify this and other keystone issues surrounding rapid climate change in Antarctica.