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Frank Stadler, Research Coordinator, National Climate Change Adaptation Research Facility, Griffith University QLD

The climate is changing and all of Australia will be affected by these changes. The Tweed is no exception. It is expected that over the next fifty years and beyond, sea levels will rise, the region will get drier, summers will get hotter and winters will have fewer frosts. Weather overall will become more variable. There is also a greater likelihood for the region to experience more natural disasters such as fires, severe storms, floods and tropical cyclones. The question is how will the Tweed cope with these changes?

Frank Stadler, Tweed resident and Research Coordinator at the National Climate Change Adaptation Research Facility (NCCARF), gave a public presentation at the Tweed Climate Action Now group’s annual general meeting last week where he introduced some of the major climate change impacts the region can expect and explained which adaptation options could be employed to cope with this change.

Adaptation is the adjustment in natural or human systems in response to climate change impacts. These adjustments aim to reduce harm but adaptation measures can also exploit beneficial opportunities that climate change may bring.

Regardless whether one accepts climate change or not, there is no denying that carefully planned and implemented adaptation has many co-benefits that extend far beyond climate change.

Careful adaptation measures can increase the sustainability of human activities, make social and natural systems more resilient, contribute to food security, provide for livable cities and enhance our quality of life.

The elderly are a particularly vulnerable group when it comes to climate change. During heatwaves overseas and in Australia the elderly make up a significant portion of hospital admissions and during the 2003 European heat wave, thousands of elderly passed away as a consequence of heat-related stress. Older people have difficulty controlling their body temperature. Often, social isolation, immobility, dementia, frailty and other medical conditions make them particularly vulnerable. Lack of financial resources can make matters worse. Installation of airconditioning, for example, may not be affordable or is not used when necessary in order to save money.

Summer days are likely to get hotter with climate change and it is highly likely that we will see more heatwaves in the future. There are, however, adaptation options. Most obvious, the homes of elderly residents should be well insulated and equipped with airconditioning to cope with hot spells.

Community health and hospital services will need to plan and prepare for more admissions of elderly residents during hot weather. However, it is the wider community that can make the biggest contribution.

Every Tweed resident can help by maintaining contact with the elderly. Regular daily visits or phone calls during hot summer days can provide much needed support and security. Elderly residents may also need to be reminded of simple coping strategies such as drinking lots of water, the wetting of the skin and cool baths.

With climate change, coastal northern NSW and south-east Queensland are likely to experience more extreme storms more often. Projections also suggest that tropical cyclones will reach further south with the potential to cause much destruction in our region.

Severe storm systems, known as East Coast Lows, have caused significant destruction in the past. The latest hit the region in May 2009. East Coast Lows mainly occur during autumn and winter and bring gale force winds, heavy rainfall and flooding. They also cause heavy swells and severe coastline damage.

Sea level rise is making matters worse. Severe storms, such as East Coast Lows, usually increase sea surface height. This higher than usual sea level adds to the tidal level and the phenomenon is known as a storm tide. The narrow continental shelf off the coast means that these storms also produce large waves with devastating consequences fort the sandy coast line. Sea level rise will add further to the overall height of the storm tide, with major consequences.

A recent CSIRO study of coastal inundation in south-east Queensland suggests that a 20 centimeter sea level rise will mean a catastrophic 1 in a 100 year storm tide of 2.5 m at Moreton Bay, is likely to recurr about every 61 years, and recurr every 38 years if sea levels rise 40 centimeters.

Sea levels are predicted to rise 20 centimeters by 2030 and 40 centimeters by 2050 which means that very soon, even low intensity storms could cause significant erosion.

According to an NCCARF and Griffith University Center for Coastal Management study on storm tides, we could see in the not too distant future “… a series of dramatic inundation and erosion events along sandy sections of the coast, which will move the beach inland”.

Because there is a high residential turnover along the coast the majority of coastal residents may never have experienced a severe storm event with coastal inundation and dramatic beach erosion.

While storm events can not be prevented, it is possible to prepare for their impact. More frequent and more severe inland and coastal flooding and coastal erosion will challenge the way we plan, develop, and protect our infrastructure and natural assets.

Conventional flood defence infrastructure such as the levy along the Tweed River in Murwillumbah is effective, but it is also costly to establish and to upgrade. It would be cheaper to avoid exposure to damage in the first place.

Options include zoning and planning measures that limit or prevent development in flood prone areas, building codes and design standards for new infrastructure and housing stock to ensure that it can handle inundation for short periods of time and clean-up is facilitated. Existing vulnerable housing and infrastructure might also need to be altered.

In order to cope with the consequences of sea level rise and greater coastal erosion all adaptation options need to be considered. This includes traditional approaches such as temporary sand bagging, longer term beach nourishment and permanent sea walls and dune protection infrastructure. However, planned retreat strategies for such properties that are simply too costly or too difficult to defend may also be considered.

The Tweed’s natural environment is also likely to be affected by climate change. Dominated by the calderra, the Tweed abounds with spectacular biodiversity and rare natural beauty. Significant habitats include rocky shore sections, mangroves, coastal wetlands and many types of forests from sclerophyll to rainforest including the ancient world heritage listed Gondwana forest remnants.

It is expected that plant growth and productivity may change. This is likely to vary between plants, some will grow better and some will do worse. The same is true for animals. Some will benefit from climate changes and others will be pushed well outside their comfort zone. This means that the composition of organisms living in any particular ecosystem in the Tweed may change with consequences to the way these ecosystems will function.

Of critical importance will be weeds, pests and diseases. Already, weeds are a major problem and bushregenerators and reserve managers spend considerable effort on weed control. This situation is unlikely to change. Weeds, pests and diseases are set to capitalise on climate change as its impacts affect native flora and fauna.

What can be done about it? Most important, reducing existing stresses on the environment will increase the resilience of the Tweed’s natural environment to climate change impacts.

This would include pest and weed management and feral animal control. Animals and plants need to be able to move to new and better suited locations. Tweed landowners can make an important contribution by providing habitat corridors for species that have to move. Critically important will be habitats that can provide refuge from climate change. They need to be identified and protected.

Traditional attitudes and approaches to nature conservation will need to change. Conservation and land management efforts will need to conserve overall biodiversity, ecosystem functions and services instead of focussing on individual species in particular places.