© CSIR 2007 www.csir.co.za

Quasi-uniform C48

grid with resolution

about 210 km

Climate Modelling at the CSIR NRE

• NWP and RCM capacity build around the conformal-cubic atmospheric model (CCAM) of the CSIRO

• A cube-based global model; semi-Lagrangian semi-implicit solution of the hydrostatic primitive equations

• Includes a wide range of physical parameterizations• Developed by the CSIRO Marine and Atmospheric

Research (McGregor, 2005) • Runs in quasi-uniform or in stretched grid mode• Multiscale forecasting...

© CSIR 2007 www.csir.co.za

CRU 3.1 linear temperature trend 1961-2009

Strong warming have occurred over the central parts of southern Africa, including the central interior of South Africa

Warming more moderate along the coastal areas

This analysis to be improved upon by using carefully designed homogeneous time series

© CSIR 2007 www.csir.co.za

CCAM-GFDL20 simulated linear temperature trend 1961-2009

Pattern correlation = 0.504

© CSIR 2007 www.csir.co.za

CCAM-MIROC simulated linear temperature trend 1961-2009

Pattern correlation = 0.555

© CSIR 2007 www.csir.co.za

CCAM ens-ave projected change in summer half-year average maximum temperature for 2071-2100 vs 1961-1990

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CCAM ensemble: projected change in annual rainfall (%) for 2071-2100 vs 1961-1990

Most models project a generally drier southern Africa, but wetter East Africa

Cloud band (TTT) related rainfall signal over central South Africa

Impacts : water resourcesProjected streamflow change with climate change

Increase

No change/decrease

Increase

No change/decrease

Streamflow

Variability of streamflow

~ 2050 ~2100

What does this all mean for the Namakwa District?

• Rainfall variability very important over short term (next 10 to 20 years) – scientific advances relevant to Namakwa district are currently being made

• Medium term (up to 50 years) – temperature and rainfall trends are likely to adversely affect water, agriculture, health, human settlement sectors (but probably not tourism)

• Long term (> 50 years) – drier and warmer future will very likely have severe adverse effects on all the above, and on fisheries and biodiversity

What does this all mean for the Namakwa District?

• Short term responses (adaptation): – Water supply security assessed and measures to optimise

water use, especially ground water– Strengthen disaster risk responses (esp. drought)

• Medium and long term response: – Urban planning to account for climatic trends– Renewable energy opportunities– Ecosystem based adaptation opportunities– Water supply enhancement opportunities– Assess high end risks and lobby for safe global temperature

goal