CLIMPACTS - AN INTEGRATED MODEL FOR ASSESSMENT OF THE EFFECTS OF CLIMATE-CHANGE ON THE NEW-ZEALAND ENVIRONMENT

A computer-based system (CLIMPACTS) is being developed for New Zealand that combines models and datasets to enable integrated assessments of the effects of climate change on New Zealand's environment. First, it draws on a global model for providing time-dependent projections of g lobal temperature change from 1990 to 2100, as a result of emissions o f greenhouse gases. The projections are then used to scale regional pa tterns of climate change, as derived from GCMs and palaeoclimatic data , to give locally relevant scenarios of changes in primary climate var iables for New Zealand on a 0.05 degrees latitude x 0.05 degrees longi tude grid. The changes in climate are used to perturb reference (1951- 80) climate data. The perturbed climate is then used to drive a number of sectoral impact models relevant to New Zealand. Preliminary develo pment has been with derived variables. namely degree days (or thermal time) and potential evapotranspiration, which provide a first-order in dication of how ecosystems may be affected in New Zealand by climate c hange. Concurrent developments include customizing of and/or developin g models for wheat, temperate and sub-tropical grasslands, fruit crops and natural vegetation,to be integrated within the CLIMPACTS framewor k.