NARCliM2.0 climate projections

<strong>What is NARCliM?</strong>

The New South Wales and Australian Regional Climate Modelling (NARCliM) project develops high-resolution regional climate projections that cover NSW and South-eastern Australia at a higher resolution and the Australasian continent and beyond at another resolution (named the NARCliM and CORDEX domains, respectively).
Computer modelled climate projections are the best information we have available on our future climate. NARCliM has been designed to help government, industry and community in NSW and Australia plan for our future with robust regional and local scale data.
The NARCliM project uses currently available global climate models (GCM) and greenhouse gas (GHG) emissions scenarios from the latest Coupled Model Intercomparison Project Phase 6 (CMIP6) used in the IPCC reports and applies regional dynamical downscaling using the latest Weather Research and Forecasting model (WRF). NARCliM generates critical climate indices for a broad range of applications and climate change adaptation and risk analysis.
The NARCliM project is led by the NSW Government with support from the ACT, South Australian, Victorian, and Western Australian governments, National Computational Infrastructure, Murdoch University and the University of New South Wales.

<strong>NARCliM2.0</strong>

NARCliM2.0 was released in the second half 2024. It is the most detailed regional climate projections available in Australia to date at 4km grid resolution for South-eastern Australia and 20km for Australasia. NARCliM2.0 simulates the climate using five CMIP6 GCMs and two RCMs with continuous data from 1950 to 2100. Rigorous and peer-reviewed analysis of CMIP6 GCMs was undertaken to identify the best-performing models for NARCliM2.0 over eastern Australia’s geographically complex and heavily populated regions. These five GCMs were chosen because they performed well in simulating various aspects of daily climate, were independent models, and showed diverse signals of climate change. This made them the most suitable group for downscaling to represent a wide range of future climates.

In 2024, two GHG scenarios, SSP1-2.6 (low emissions) and SSP3-7.0 (high emissions), for the years 2015-2100, were released. Historical simulations for the years 1950-2014 were also released. In 2025 a third scenario, SSP2-4.5 (middle of the road emissions) and 30 climate indices for all three scenarios and the historical period were released. Shared Socioeconomic Pathways do not estimate the relative likelihood of any scenario. Since any future scenario is plausible, it is best to consider multiple scenarios and the full suite of 10 models where possible. NARCliM2.0 has been designed to WRCP-CORDEX (https://cordex.org/) standards. Additionally, the 4km grid resolution over South-eastern Australia, covering an area that includes 5 capital cities, is considered 'convection permitting' in that it more reliably captures convective processes like strong winds, extreme rainfall, storms and coastal atmospheric dynamics. NARCliM provides users with state of the art climate projections for Australia at the finest resolution currently available.

Each generation of NARCliM is based on best available climate modelling and scenarios at the time of release. Consequently, there are expected differences between projections/results of the modelling but there are mostly similarities in trends (across NSW and over time).

<strong>Model output</strong>

NARCliM2.0 contains approximately 150 climate variables defined by CORDEX guidelines. The most commonly used variables (CORDEX CORE) at daily and monthly frequencies in regular grid are now available on the NSW Climate Data Portal (https://www.climatechange.environment.nsw.gov.au/climate-data-portal). This includes 15 post-processed variables, 3 static variables and 3 bias-adjusted variables. Additionallly, the Portal serves 30 climate indices (ET-SCI) at mostly monthly and yearly frequencies. Additional variables and frequencies/time steps are available on the National Computational Infrastructure at ANU (https://dx.doi.org/10.25914/ysxb-rt43).  For more information, visit the AdaptNSW website, or contact us through the NARCliM Mailbox, narclim@environment.nsw.gov.au. 

<strong>Related links</strong>

New South Wales Climate Data Portal (https://www.climatechange.environment.nsw.gov.au/climate-data-portal)

Discover how climate change will affect your region at <a href="https://www.climatechange.environment.nsw.gov.au/projections-map">AdaptNSW</a>

Tags: CLIMATE-AND-WEATHER, CLIMATE-AND-WEATHER-Climate-change, projections
Organization: NSW Department of Climate Change, Energy, the Environment and Water