Climate change in Metropolitan Sydney

Key points

The Metropolitan Sydney region is home to about 5 million people, making it Australia’s largest city. The region is a hub of diverse economic and cultural activity, which contributes significantly to the city, state, nation and the world.
Climate change is affecting the region, particularly through sea level rise along the coast, flooding in river catchments, bushfires in forested areas and increased temperatures causing more heatwaves and urban heat islands.
Understanding the region’s vulnerability to climate change is key to adaptation and resilience. The NSW Government, along with local councils, have taken several steps to assessing and planning for climate risk and adaptation across the region.
The NSW Government’s Integrated Regional Vulnerability Assessment (IRVA) work helped identify some of the region’s key vulnerabilities to climate change. The knowledge and partnerships gained through this work will continue to build the resilience of vulnerable aspects of the region, and create a more sustainable, productive and equitable future for all Metropolitan Sydney residents.

Importance of the Metropolitan Sydney region

The Metropolitan Sydney region includes major cities, towns and regions, such as Wollondilly, Campbelltown and Sutherland to the South, Blue Mountains to the west, Hawkesbury, and Hornsby and Northern Beaches to the north. To the east the region is bordered by the Tasman Sea.

The region has a wide range of landscapes, ranging from coastal areas with popular beaches, to the rugged ranges of the Blue Mountains in the Great Dividing Range, to the Illawarra Escarpment to the south. The lower-lying Sydney basin is characterised by wide landscapes with low, undulating hills and river systems. The region includes stunning natural assets including national parks which have cultural and world heritage significance.

As Australia’s largest city, Sydney is the main gateway to Australia from the rest of the world. Metropolitan Sydney contains a culturally diverse population of about 5 million people – or around 1 in 5 Australians.

The region is a hub of diverse economic and cultural activity, which contributes significantly to the city, state, nation and the world. Hospitality and food services employ more than 20% of the population. Other significant industries include professional, scientific, and technical services. Public and private infrastructure supports the values of the region, connecting people to places and services, and supporting businesses and lifestyles.

These environmental, economic and cultural values are just some aspects of the region which have been identified as being highly vulnerable to climate change. Climate change is already affecting the Metropolitan Sydney region, particularly through increased temperatures and more extreme weather events. The impacts of these changes can be seen through the widespread bushfires of 2019–2020, increased coastal erosion and severe flood events.

How Metropolitan Sydney is affected by climate change

Metropolitan Sydney is getting warmer

The warmest year on record for both average temperature and maximum temperature in the Metropolitan Sydney region was 2019, when average temperature was 1.1°C above the 1990–2009 average.

Projected warming

Across Metropolitan Sydney, average temperatures will continue to increase throughout this century. By 2090, average temperature is projected to rise by around 1.2°C under a low emissions scenario and around 3.4°C under a high emissions scenario.

Interpreting the projections

The projections provide a summary of plausible future climate change in Metropolitan Sydney relative to a baseline of average climate from 1990–2009. Unless otherwise specified, the presentation of data on this page is averaged across a 20-year period from the NARCliM model ensemble. For example, the projections for 2050 represent averaged data for 2040–2059 and projections for 2090 represent averaged data for 2080–2099. In translating the projections, it is important to consider the previous historical changes that occurred prior to 1990-2009. For example, national temperature records indicate that NSW has warmed by 0.84°C between 1910-1930 and the 1990-2009 baseline.

Detailed information on the projected climate changes for Metropolitan Sydney can be found in the Metropolitan Sydney Climate change snapshot or explored further through the interactive climate change projections map.

Hot days

The annual number of hot days 35°C and above is projected to increase for Metropolitan Sydney by 2050. By 2090, under a high emissions scenario, the region is projected to experience more than triple the annual number of hot days, compared with the 1990–2009 average.

Increases in hot days are projected to occur across the region, with Greater Western Sydney to experience the greatest increases.

Cold nights

The annual number of cold nights below 2°C is projected to decrease for Metropolitan Sydney by 2050. By 2090, under a high emissions scenario, areas of the Blue Mountains are projected to experience an 80% reduction in the annual number of cold nights, compared with the 1990–2009 average.

Coastal areas are projected to experience limited changes, as they do not typically experience cold nights.

Rainfall

Annual average rainfall in the region is projected to remain variable throughout this century. On average, winter rainfall is projected to decrease by 20-35% by 2090.

Severe fire weather

On average, the annual number of severe fire weather days is projected to increase for Metropolitan Sydney by 2050. By 2090, under a high emissions scenario, the annual number of severe fire weather days are projected to more than double for the region, with the largest increase in spring.

Greater Western Sydney is projected to experience the greatest increases.

Sea level rise

A sea level rise of 3.7mm/year has already led to increases in inundation of streets in some NSW coastal communities.

Sea level for Metropolitan Sydney is projected to continue rising under all emissions scenarios. At Fort Denison, sea level is projected to rise by 12–25cm under a low-emissions scenario and by 16–29cm under a high-emissions scenario by 2050. Later in the century, sea-level rise is projected to accelerate under both emissions scenarios, with significantly faster acceleration under a high-emissions scenario. Sea-level rise by 2100 is projected to be 25–58cm under a low-emissions scenario and 51–92cm under a high-emissions scenario.

These projections are relative to a baseline period of 1995–2014. For more detail on the methodology, please access the Metropolitan Sydney Climate Change Snapshot.

Communities, infrastructure and natural ecosystems are expected to be increasingly vulnerable to the impacts of sea level rise in the future, particularly under a high emissions scenario. Find out more about the impacts of sea level rise.

Adapting to changes in the Metropolitan Sydney region

To help the Metropolitan Sydney region adapt to the impacts of climate change, state and local government stakeholders were brought together in 2014 as part of the NSW Government’s Towards a Resilient Sydney (TARS) project.

The project aimed to:

develop improved information of climate risks for the Metropolitan Sydney region
assess vulnerability to climate risks
identify responses and opportunities to help local communities to improve resilience and reduce impacts.

This work also included an assessment of some of the regions key values which have been identified as being vulnerable to climate change. These vulnerabilities will be reviewed and updated to ensure they continue to reflect climate trends, key vulnerabilities and community values. Full details are provided in the Integrated Regional Vulnerability Assessment: Metropolitan Sydney – Volume 1: Regional vulnerabilities report.

With the knowledge and partnerships gained through the Towards a Resilient Sydney project, there is an opportunity for council, government and communities to show leadership and consider this work in the plans to respond to climate change.

How we’ve been adapting so far

Some actions are already being taken by government, community, households and business, to help the Metropolitan Sydney region adapt to the impacts of climate change and build a sustainable, productive and equitable future.

Examples of action include the Resilient Sydney project and the Western Sydney IPC Program.

The Resilient Sydney project – a partnership between all councils in the Metropolitan Sydney region. The project outlined 5 directions for the city to take to make it more resilient in the future. The project was hosted by City of Sydney 100 resilient cities network.
The Western Sydney PIC Program, led by the Greater Sydney Commission. The program is focused on planning and assessing climate risk assessment for all of Western Sydney.

The Increasing Resilience to Climate Change community grants program provided $600,000 in the first round of grants. Projects for Sydney included:

Building Responsiveness to Climate Change in Migrant and Refugee Settlement Communities Metro Assist. The project delivered resources in different languages to help people understand the impacts of climate change.
Cool River City. This project taught Western Sydney’s culturally diverse population ways to respond to climate change.
Western Sydney Heat and Social Housing. This project focused on improving people’s resilience to heat and heatwave events by developing resources in plain English and other languages.
Learn, Prepare, Prevent: Action for a Resilient Hawkesbury. This was a community education, engagement and empowerment initiative to help households, villages and the Hawkesbury region to respond to climate change impacts.

The Towards a Resilient Sydney work has helped inform the development District Plans for the Metropolitan Sydney region. These 20-year plans help connect regional and local planning to inform local environmental plans, community strategic plans and the assessment of planning proposals. District Plans also help councils to plan and deliver for growth and change, including increasing resilience to climate change impacts.

If you have an example of how a community group, business or local government is adapting to climate change, email AdaptNSW so we can share your story.