Effects of Climate Change on Storms and Flooding

Various factors contribute to the occurrence of storms and floods throughout New South Wales (NSW).

Common types of storms include:

• Thunderstorms, prevalent from October to March due to warmer weather.
• Tornadoes, characterized by high wind funnels often accompanying thunderstorms.
• Tropical cyclones, bringing strong winds, heavy rainfall, and flooding to northeastern parts of NSW.
• Low-pressure systems and troughs, including east coast lows.

East coast lows, particularly significant in coastal areas of NSW, emerge when an intense low-pressure system forms off the eastern coast of Australia. These systems frequently bring gale-force winds, heavy rainfall, and hazardous surf conditions. Occurring approximately ten times annually, particularly during autumn and winter, these storms can escalate rapidly, posing significant dangers.

Furthermore, east coast lows contribute essential rainfall for replenishing catchments and water reservoirs along the NSW coast and adjacent ranges.

Natural climate phenomena, such as the El Niño Southern Oscillation (ENSO), can trigger severe flooding across NSW. ENSO, which cycles every 3 to 7 years, transports moist air from the Pacific Ocean over NSW, resulting in either above-average rainfall and flooding or reduced precipitation.

Impacts of Storms and Floods in NSW

While storms and floods play a crucial role in providing essential rainfall, they also pose significant risks to communities, businesses, and environments. Annually, flooding costs the NSW economy an estimated $250 million, causing property damage, infrastructure disruption, and adverse health effects.

East coast lows, with their heavy rainfall and hazardous surf, lead to coastal erosion, affecting beaches, infrastructure, and coastal habitats. A notable event occurred in June 2016, resulting in widespread damage, flood rescues, and loss of life.

Climate Change’s Influence on Storms and Floods in NSW

Long-term climate change, marked by rising temperatures since 1910, heightens the likelihood of extreme weather events, including heavy rainfall and coastal storm surges.

Increased temperatures may amplify the frequency of thunderstorms during warmer months, while altering natural climate processes like ENSO could disrupt rainfall patterns and flood occurrences.

Climate projections suggest more extreme low-pressure systems during warmer months, potentially intensifying east coast lows. Sea level rise exacerbates coastal storms and floods, impacting shoreline erosion and flooding.

Adapting to Storms and Floods in NSW

To mitigate storm and flood risks, proactive measures are essential. Local councils, supported by the NSW Government, manage flood risks, considering land development, flood mitigation structures, and community education.

The NSW Government facilitates community resilience, emergency planning, policy development, and rural floodplain management. Furthermore, local flood studies and research on east coast lows contribute to planning efforts, aiding in understanding and preparing for future events.