Preparing for climate impacts

To understand what our future climate will be like, the Antarctic Climate and Ecosystems Cooperative Research Centre modelled potential climate impacts across Tasmania in the Climate Futures Project and developed Local Government Area Climate Profiles.

From this we prepared more detailed information accounting for a range of climate variables across 30-year time intervals to 2100 in Hobart climate change information for decision making(PDF, 714KB). You can also view a summary document with climate projections in the Hobart Climate Snapshot(PDF, 489KB).

The key findings are detailed below. 

Current climate and recent trends

• Hobart has a temperate, maritime climate with relatively mild winters. Long-term average temperatures have risen in the decades since the 1950s, at a rate of up to 0.1^oC per decade.
• Despite covering a small geographic area Hobart experiences a marked rainfall difference in average annual rainfall from about 1100 mm on the slopes of kunanyi/Mount Wellington to 615 mm in the city.
• There has been a decline in average annual rainfall since the mid 1970s, and this decline has been strongest in Autumn.

Projected change in conditions by 2100

Table 1: Projected changes for Hobart by 2090–99 relative to the baseline period (1980–99)

Climate change variable	Change	Relative change
Temperature (annual average)	+2.6–3.3oC
Summer days (>25oC)	+22 days	+120%
Warm spells (days)	2–6 days longer	+50–150%
Hottest day of the year	+3oC
Frost risk days/year	-9 days	-90%
Rainfall (annual average)	Increase in all seasons
Rainfall (wettest day of the year)		+25%
Rainfall extreme (ARI – 200)	+30–40 mm	+30–40%
Evaporation		+19%
Runoff	Increase in all seasons
Coastal inundation	100-year event becomes a 2–6 year event

Extreme events

Potential impacts on Hobart by 2100:

• The temperatures of very hot days are projected to increase by up to 3^oC.
• Warm spells (days in a row where temperatures are in their top 5%) currently last around 4 days and will increase by days.
• Extended heat waves and more extreme temperatures are likely to enhance the occurrence and intensity of bushfires.
• Rainfall will be heavier but there will be longer dry periods.
• High daily runoff events are likely to increase, which may lead to erosion or flooding. Rainfall volume in a 200-year average recurrence interval event will increase by up to 30–40%.
• Inundation along Derwent Estuary frontage will increase.
• The current 100-year storm tide event is around 0.9–1.4 m above average sea level. Accounting for sea level rise (0.82 m), the current 100-year coastal inundation event may become a 50-year event by 2030, and a 2–6 year event by 2090.