Issues Magazine

Climate Change: Adapt Now for the Future

By CSIRO Climate Adaptation National Research Flagship

For Australia, climate change is emerging as one of the most profound challenges of the coming decades. The choices and plans we make as a society to address this challenge will affect our future social, economic and environmental resources.

Times Are Changing
The globe is at its hottest in 12,000 years, having already warmed by 0.7ºC since pre-industrial times. We are now confident that the world will see 2ºC global warming within the lifetime of the current generation. Without firm and rapid action to reduce CO2 emissions, there is a serious risk that this warming could be as much as 4ºC by later this century. Notably, 4ºC warming across the globe means at least 5ºC warming over continental Australia.

Climate change is the physical expression of complex global changes. Most of us understand that more greenhouse gases in the atmosphere leads to warmer air, land and water temperatures. These result in melting ice, higher energy storms and shifts in patterns of rainfall, runoff and evaporation. Increased CO2 also contributes to changed chemistry of the environment.

Changes in the environment affect humans and the systems on which they depend. The changing climate affects food production, disturbs coastal margins, displaces species, and changes economies as it affects our trading partners differently to ourselves. In some places new extremes in temperature and sea level will exceed the habitable limit for some species, including humans. Shifting population patterns of plants, animals and people will bring more changes.

Australia Is at Risk
We know that Australia is particularly vulnerable to many of the climatic changes projected by CSIRO and other international scientists. Our water supplies, coastal settlements, agriculture and natural ecosystems are particularly affected by climate change. In fact, we have been assessed as one of the developed nations that are most vulnerable to climate change.

From the first Australians to farmers and urban planners, our people have been constantly adapting to a highly variable and sometimes surprising climate. But if drought and heatwaves get longer and more severe, sea level increases, bushfires get more intense and water tables drop then we have to rethink our ways of coping. This is adaptation to climate change.

Adaptation Has Already Started
Adapting Brings New Challenges
Adaptation is not new. Australians adapt to changes in their environment, the price of fuel, the availability of different foods, changing building regulations, water restrictions and varying exchange rates all the time. We need to begin to incorporate climate change into all these considerations, and that does bring some new challenges. Adapting to changing futures needs to begin today.

Some changes are more certain and more immediate. Some changes are quite certain: we know temperatures are rising on average; we know sea level is rising almost everywhere; in some regions such as south-western Western Australia we know average annual rainfall has declined. For these sorts of changes, new incremental adaptations will often follow on from current strategies.

Australian agriculture has always had to deal with our highly variable weather patterns in the past. Already, to determine planting times and choose the right crop cultivars, many Australian farmers track online climate indicators, commodity forecasts and input costs. Australian farmers are now building on these climate considerations to plan for the future in a more variable climate system.

Extremes Will Test Us
No one actually experiences average temperature – we feel the highs and lows of each day and each season. It is these extremes that will test us. By 2030 Australian capital cities will probably experience a doubling of days above 35°C and of heat waves. In Canberra, for example, the present annual average of five days over 35ºC may rise to 10 days by 2030 and 26 days by 2070.

Engineers can adapt their designs to allow for new extremes – higher heat tolerances in power transmission lines, concrete sleepers to reduce the risk of railway lines buckling, higher bridges to allow for more severe storms on top of sea level rise, and stronger buildings to cope with increased wind speeds. Adaptation also means that building codes and specifications for new infrastructure investments will have to be updated over time instead of relying on the fixed values of the past.

Some Changes Will Require Transformation
At some point the changes needed will be too big for regular small adaptations to be sufficient – sea level may rise too high, and high temperatures and lack of water may make farming in some regions uneconomic. Bigger adaptations may be needed – relocating houses or moving farm systems elsewhere, often with the assistance of the wider community or the nation. For example, changes in bushfire regimes and an increased number of fires that cannot be fought may require these transformative adaptations. In some areas, new building designs, hazard reduction and exit strategies will be effective incremental adaptations. In others, people may choose transformation and change their residence, their business and even their location.

The Long-Term Future Is More Uncertain
What the climate will look like in 2100 is very uncertain. About half the uncertainty is because we don’t know what CO2 emissions trajectory the global society will choose to follow. The other half is scientific uncertainty about how the earth will respond to these emissions. For short-term decisions, like which crop to plant next year, long-range uncertainties don’t matter – farmers can adjust these decisions incrementally as time goes by.

But there are some decisions, like planning a new suburb or farming area, that have very long-term implications. Where these decisions could be affected by sea level or water supplies in 2100, the uncertainty must be dealt with by adaptation that takes into account well-known principles of risk management.

Fostering Adaptation Practices
Successful adaptation to climate change requires both strategic preparation and tactical responses. Current “best practice” to cope with adverse conditions, including drought, extreme temperatures and coastal inundation, will form the foundation of new adaptations. The costs of adapting new infrastructure to changing climates can be included in the planning and design stage.

Renewing and adapting infrastructure once it is constructed can be much more difficult and costly. To implement these new practices, we need to have:
• confidence that the climate really is changing;
• motivation to change in order to avoid risks or seize opportunities;
• demonstrated benefits of new adaptation options;
• support during transitions to new management or new land use;
• capacity for communities to develop and implement adaptation strategies;
• altered transport and market infrastructure; and
• an effective system to monitor, evaluate and adjust policy and management decisions over time.

Adapted with permission from Change: Adapt Now for the Future and Adaptation Science: Opportunities and Responses to Climate Change Impacts