Australian utilities and agriculture are among the most exposed sectors if the El Nino climate phenomenon emerges, while thermal coal producers could be one of the few clear beneficiaries, Fitch Ratings said in a report on Thursday.

Hotter and drier conditions associated with El Nino would increase water stress, weaken agricultural output, raise peak electricity demand and heighten bushfire risk, although impacts would vary by region, Fitch noted.

The drier conditions can reduce water storage levels and inflows, which may weaken revenue and increase water utilities' operating expenditure through greater use of desalination plants and chemical treatment, the credit ratings agency added.

Hotter weather could also increase electricity demand, putting pressure on spot prices and grid stability while raising bushfire-related risks for transmission and distribution assets, Fitch said. However, for regulated utilities, regulatory frameworks in place will limit most of the credit impact through revenue cost recovery in subsequent years.

El Nino typically brings lower rainfall, weaker pasture growth, lower crop yields and irrigation stress. Farm output could fall, pressuring food supply chains and increasing food price volatility. Australian wheat and barley production volumes fell by an average 28% and 18%, respectively, in El Nino years, according to Australian Bureau of Agricultural and Resource Economics and Sciences and BOM

Thermal coal producers could be one of the few clear beneficiaries. Drier conditions generally lower the risk of weather-related disruptions and could lead to higher supply volumes. Hotter weather across Asia and lower hydropower availability could also support seaborne thermal coal demand and lift prices, benefiting Australian exporters.

Credit effects are likely to be limited for sectors with contractual protections or strong operational resilience, Fitch said.