Understanding Climate Change

To understand Climate Change, it is important to first understand the differences between the terms 'weather' and 'climate'. Weather describes what is happening in the atmosphere at a specific time or on a day-to-day scale. Weather summarises if it is hot or cold, wet or dry, sunny or cloudy, windy or calm.

In contrast, climate can be defined as average weather. As such, climate change and weather are intertwined. Observations show that there have been changes in weather over time and such statistical change in weather identifies climate change.

While weather and climate are closely related, there are important differences. The fluctuating nature of weather makes it unpredictable beyond a few days. However, projecting changes in climate (i.e. long-term average weather) due to changes in atmospheric composition is easier. Climate science can now project changes in climate many decades into the future.

One common mistake people make is considering unusually cold weather as ‘evidence’ against climate change. Our variable weather always delivers extremes of hot and cold. The frequency and intensity of individual weather events is changing as the climate changes. But when weather is averaged over space and time, the fact that the globe is warming emerges clearly from the data.

Climate Change is caused by the acceleration of the Earth's Greenhouse Effect. Carbon dioxide (CO₂), methane (CH₄), nitrous oxide (N₂O) and water vapour (H₂O) (often called ‘greenhouse gases’) naturally trap heat within the atmosphere to act as a blanket necessary for life on Earth. However, since industrialisation and increased burning of fossil fuels, the concentration of atmospheric gases, particularly CO₂ and CH₄ has increased significantly.

Naturally produced greenhouse gas concentrations in the atmosphere fluctuate over time, but they are now much higher than at any time in the past 800,000 years. Before the Industrial Revolution began in about 1760, CO₂ levels in Earth’s atmosphere averaged around 280 parts per million (ppm). Scientists know this from their analysis of air bubbles in ice cores. In May 2022, Tasmanian levels were 414 ppm and they continue to increase.

We know that current levels of heat-trapping CO₂ in the Earth’s atmosphere are caused by human activity and are not natural because the steep increase in atmospheric concentration of CO₂ corresponds closely with increased anthropogenic burning of fossil fuels. No other physical processes are consistent with these levels of heat trapping greenhouse gases.

The City of Launceston completed a detailed greenhouse gas desktop audit (also known as a carbon footprint) for Council operations for the 2018/19 financial year. Council's emissions reporting boundary was established following the approach of the Australian Government’s Climate Active standard which is based on the GHG Protocol and the National Greenhouse and Energy Reporting (NGER) Measurement Determination.

Rising Temperatures

Mean annual temperature has risen by approximately 0.4°C in recent decades. This increase has been consistent for all parts of the Launceston region. Mean annual temperature is projected to continue to increase in the future.

Very little change in mean Excess Heat Factor (EHF) (i.e. during a heatwave) has occurred in recent years in Launceston (comparing 1997-2017 to the baseline period 1961-1990). Excess Heat Factor will increase in future decades:

• although, extreme heat is not expected to be a major risk for Launceston in the future
• the temperature thresholds of 35°C and higher will only rarely be exceeded and only 5 days per year are expected to pose a severe risk to humans working outside

The mean number of frost risk days (any day when daily minimum temperature is <2°C) across the Launceston region have slightly decreased by 0.5 days per year for lower altitudes, and up to 5 days per year for higher altitudes (comparing 1997-2017 to the baseline period of 1961-1990).

Frost risk will continue to decline into the future:

• in some areas the number of frost risk days will halve and in other areas, there will be no frost risk days
• along with increased bushfire risk, the reduction in frost days is likely to be one of the most distinct climate impacts in the Launceston region, with important implications for fruit growers in the future

What does this mean for Launceston?

Potential impacts of rising temperatures to residents, visitors and businesses in Launceston could include:

• negative health impacts due to higher temperatures or heatwaves, particularly for vulnerable community members
• impacts of higher temperatures, heatwaves or the reduced occurrence of frost on the economy and businesses, particularly fruit growers that rely on frost

A slight drying trend is predicted across the region in future decades, although rainfall will continue to be variable, with some wet years and some dry years. 

If the global temperature is kept in the 1, 2, 3 and 4°C thresholds projections indicate that there is little change projected for monthly rainfall for the Launceston region.

The Aridity index is expected to increase across the region, indicating a drying trend across the region, with more change towards the eastern part of the Launceston region.

However in the western and northern parts of the Launceston region, drying has occurred, with the aridity index increasing by up to 10% in some areas. Towards the east, the aridity index has decreased by ~4%. This regional difference reflects the observed differences in temperature.

This allows us to understand Launceston’s possible future temperature under a range of global warming scenarios.

How does this affect us?

As temperature increases, evaporation increases, so even when large rainfall declines are not projected, the landscape becomes drier. Therefore, potential impacts could include:

• impacts of reduced water availability on residents, the economy and businesses including stress and resources required for maintaining vegetation and agriculture

Fire risk across the year is predicted to change, with the fire season lasting longer into the future. Forest Fire Danger (FFDI) risk is expected to increase particularly in spring. This means there will be a narrower window of suitable conditions for prescribed burning in the future.

This will significantly impact the ability to carry out hazard reduction burning, which is used to reduce the risk posed by high fuel loads across the landscape.

Projections of bushfire danger under future climate conditions suggest that fire danger will increase across Tasmania over the next decades.

The frequency of low-moderate fire danger days will decrease, with an increase seen in the number of days per year of High, Very High, Severe and Extreme fire danger days in the Launceston area also. 

Potential impacts of bushfires to residents, visitors and businesses in Launceston could include:

• reduced capacity for hazard reduction burning
• negative health impacts due to an increased presence of smoke, particularly for vulnerable community members
• increased fire threat to public and private properties and assets
• increased fire threat to the general public

Flood risk in Launceston is caused by the combination of flooding from the North and South Esk Rivers and high-water levels as storm tides move upstream along the kanamaluka/Tamar estuary.

City of Launceston acknowledges the flood risk under current climate conditions. However as sea level rises and extreme weather events are predicted to increase in the future due to climate change, flooding is expected to change in the Launceston area resulting in a potentially unpredictable climate.

In recent years it has been projected that the levee system that is currently in place has the capacity to handle a significant increase in intensity for most extreme weather events.

Further research is undertaken to monitor the flood risk in Launceston.

This unpredictable signifies the importance of reducing environmental impact in relation to climate change and how it could affect the region.

Climate Change Targets and Progress

• Achieve carbon neutrality for all operations by 2025
• Source 100% renewable energy for all Council owned buildings by 2025

Additionally, Council became a member of the Cities Power Partnership (CPP) and committed to five pledges:

• Power council operations by renewable energy, and set targets to increase the level of renewable power for council operations over time
• Encourage sustainable transport use such as public transport, walking and cycling through council transport planning and design
• Support cycling through provision of adequate cycle lanes, bike parking and end-of-ride facilities
• Lobby state and federal governments to increase sustainable transport options
• Achieve 100% divestment from fossil fuel aligned investments at the earliest possible date

If this discussion raises issues for you, or if you’re concerned about someone you know, call Lifeline on 13 11 14.

Given the magnitude of the impacts from climate change globally, many people have emotional responses to our changing climate. The mental health impacts of climate change are real, and they are on the rise. People feel anger, powerlessness, outrage, fear, grief and anxiety in relation to climate change. These are justifiable emotions given the projected global impacts, and the losses already underway. In addition, people who have directly experienced climate-related disasters like bushfires and floods, may report symptoms consistent with post-traumatic stress disorder (PTSD). 

The field of research known as environmental psychology is interested in better understanding how to deal with the ways that the impacts of climate change affect mental health. Environmental psychology research tells us that talking about how we feel about climate change is the first step towards dealing with climate change-related mental health issues. It also tells us that engaging in pro-environmental behaviour like acting to mitigate and adapt to climate change is the best way to protect against the mental health impacts of climate change. Put simply, the best solution to climate anxiety is action. See the sections on community responses on this website to help you think through how you can best take action, and get involved with other like-minded people taking action on climate change.

It’s also important to remember that those who feel worried about climate change in Australia and want to see action are a large majority, as polls have increasingly shown. 79% of Australians are concerned about climate change and 84% say they want to see some action on climate change. 83% of Australians say that they deal with their own climate anxiety by taking action.