The CLIMPACTS program began in 1993, with funding from the New Zealand Government, and has continued for 14 years. The program was led by the International Global Change Institute (IGCI) at the University of Waikato and involved collaboration with other research organizations based in New Zealand.
From the outset, the focus of the program was on the development of the CLIMPACTS model system, designed to examine, in a spatial and temporal context, the sensitivity of the managed environment to climate change and variability.
In developing CLIMPACTS, the 'game plan' was to gain confidence in the ability to assess biophysical effects of climate change and variability on agriculture, and then to turn attention to other sectors and the human dimensions of change. One of the main aims of the CLIMPACTS program during the 1990s was to develop the capacity for multi-scale spatial and temporal analyses both nationally and sub-nationally, and at individual sites.
As envisioned, this capacity would extend to the functions for generating scenarios of climate change, as well as to the impact and adaptation analyses based on those scenarios. These functions provided the foundation for later models. For example, with the spatial mode, one is able to generate 'time-slice' comparisons of spatial changes in climate means (yearly, seasonally, or monthly). With the site specific mode, one is able to generate projections of changes in climate variables or perturb existing time-series data (monthly, daily, or hourly).
Through the 1990s a complementary regional-scale capacity for spatial analysis was subsequently developed within CLIMPACTS for New Zealand applications. Detailed land data and vector files (e.g., roads and property boundaries) could also be imported into the system for spatial overlays which are important for impact assessment and planning. The spatial resolution, currently at a 100 m grid, is much finer than that of the national-scale model, but the range of modeling capabilities is similar.
A site-specific modeling capacity was also developed within the early CLIMPACTS system. While non-spatial, this capacity allows for the inclusion of time-series data and more in-depth analyses, especially as regards variability and extremes, both in terms of climate itself and its present and future impacts.
An extreme event analyzer was also developed that allows the user to fit a generalized extreme value (GEV) distribution to observed (and perturbed) extreme values from daily or hourly time-series data. This function allows the user to estimate the return periods of extreme events and their exceedance probabilities. The extreme event tool is especially valuable for supporting risk-based assessments of impacts and adaptation.
Over the period 1995-2001 the CLIMPACTS model structure was "cloned" for other problems and to other geographical settings and countries.
The relatively simple, end-to-end structure was especially appealing for the purpose of developing. In the first instance, a platform for assessing the first-order, biophysical impacts of climate variability and change upon which more sophisticated tools could be added.
Some examples of these extensions include: the model OzCLIM, developed for Australia in collaboration with the CSIRO Division of Atmospheric Research; BDCLIM, developed for examining climate change and flooding in Bangladesh, with funding from the Ford Foundation; and VANDACLIM, a training tool developed initially for the United Nations Institute of Training and Research. These and some other "clones" were built on the core framework of the CLIMPACTS system.
The original CLIMPACTS model was envisaged as a tool for bridging science, policy, and planning. Evolution of the model system should thus be driven by end-user needs as well as by science, and should be created in a manner accessible to planners and policy makers.
With these principles in mind, steps were taken, beginning around the year 2002, to create the "next-generation" model. The aim was to build on the existing functionality of CLIMPACTS and to nudge it into being an active support tool for evaluating options for adapting to climate variability and change.
In order to increase the flexibility and the accessibility of the system to a wider range of users, a generic "open-framework" structure was developed. The new system was re-named SimCLIM. The open structure of SimCLIM and its interfaces allow users to define geographical boundaries and spatial resolution, enter spatial data and downscaled GCM patterns, import time series climate data for sites, and attach "SimCLIM-compatible" impact models. In effect, with the open-framework structure SimCLIM has made significant strides in providing a modifiable system that can be put in the hands of analysts, planners, educators, and decision makers, and customized to meet user needs.
Improvements were thus made to allow the incorporation of geo-referenced demographic, land-use, and infrastructural data, and to explicitly link them to biophysical impacts arising from climate and sea-level variability and change.