Annual report 2005-06.indd - Antarctic Climate and Ecosystems ...

sea-level riseProgram LeaderDr John ChurchCSIRO Marine & AtmosphericResearchSea-level rise as a result of climatechange may affect millions of peopleworldwide in coming years. Acombination of higher sea level, possiblycombined with stronger winds, could alsocause more frequent flooding in coastallowlands and put billions of dollars ofcoastal development at risk.Scientists in the ACE CRC Sea-level RiseProgram are helping Australia preparefor these possibilities by improving ourability to project and respond to futurechanges based on better understandingof historical sea-level change and thefactors that contributed to it.Program Objectives• To narrow estimates of the range of 20 thcentury global-averaged and regionalsea level rise. Through analyses of historicaland new data, including tide-gauge recordsand satellite-altimeter measurements, ACECRC researchers are significantly enhancingour knowledge of sea-level rise over the pastcentury. This knowledge is improving ourability to test models that project future sealevels and increasing our confidence in thoseprojections.• To improve estimates of the differentcontributions to 20 th century sea-levelrise. ACE CRC scientists are using in situ andsatellite observations and measurements,combined with computer modelling, toimprove our understanding of how differentprocesses interacted to affect sea-level riseand its regional distribution during the 20 thcentury. This will help reduce uncertainties infuture projections, especially at regional andlocal scales.• To significantly reduce the range of 21 stcentury projections of sea-level rise.ACE CRC research results are helpingincrease the precision of projections forglobal average and regional sea levels inthe 21 st century to enable society to developappropriate responses to projected changes.• To forecast change in extreme eventsduring the 21 st century for strategiclocations. ACE CRC researchers areassessing how climate change will affect thefrequency and intensity of natural extremeevents around Australia and selected SouthPacific locations. This will help coastalplanners assess the vulnerability of differentparts of the coastline and provide guidancefor adaptation and mitigation strategies toprotect coastal communities and assets.• To address key uncertainties in thelonger-term projections of sea level rise.Sea level will continue to rise after 2100,potentially by several metres, because ofongoing warming and resultant expansion ofthe ocean, as well as changes in the Antarcticand Greenland Ice Sheets. The rate andamount of rise are uncertain, however, andreducing that uncertainty is another focus forACE CRC research.42 Antarctic Climate & Ecosystems CRC - Annual Report 2005-06