The natural greenhouse effect warms the planet to an optimum temperature for life on Earth. For millions of years, water vapour, carbon dioxide, methane and other greenhouse gases have occurred naturally, heating the atmosphere and making Earth liveable.
However, human activities - mainly from the burning of fossil fuels, intensive agriculture and land clearing - have tipped the balance and are causing greenhouse gas concentrations to rise above natural levels. The enhanced greenhouse effect has resulted in the planet warming beyond optimum conditions.
As global temperatures rise, weather patterns worldwide have changed and will continue to change, affecting the long-term climate. The enhanced greenhouse effect is often called global warming or climate change.
What are the impacts?
Australia is very vulnerable to the effects of climate change. It is the driest inhabited continent on earth, heavily exposed to the dangers of extreme heat, drought and other extreme weather events.
The impacts of climate change are already being felt locally and worldwide, and will increase into the future. Much of Victoria, including Hume, has recently experienced drought conditions lasting more than a decade and severe local weather events. Hume is particularly vulnerable to climate change impacts due to the demographic make-up (people on low incomes and from diverse cultures are more at risk of climate impacts), biodiversity values and the large proportion of the municipality that is rural – with agricultural activities already threatened by low rainfall. Due to Hume’s status as a growth area, there are also opportunities to plan and influence new development to be well suited to future climate conditions.
Some of the direct climate change impacts for south eastern Australia will include:
- Hotter, drier conditions
- Reduced overall rainfall
- More extreme weather events including storms, strong winds, hail and heavy downpours
- Rising sea levels.
These impacts will give rise to a greater number of and more intense extreme events including:
- Heat waves
There are also secondary impacts of climate change (impacts arising from direct climate impacts) such as:
- Spread of diseases, e.g. spread of mosquito borne diseases such as Dengue Fever and Ross River virus
- Health and wellbeing, e.g. heat stress, mental health issues
- Food and agriculture, e.g. land no longer suitable for agriculture, damage to crops
- Biological cycles, including a reduction in the fertilisation of food crops
- Energy cost increases
- Insurance cost increases and/or difficulty in securing insurance cover
- Climate refugees - people relocating due to climate impacts in their home countries.