Today the Intergovernmental Panel on Climate Change (IPCC) Working Group II released its Fifth Assessment Report, which focuses on the vulnerability of natural systems to climate change, the impacts, and adaptation options. While some of the consequences of a warming climate are unavoidable, adaptation strategies can help to manage some of the impacts. CSIRO is involved with the IPCC in a range of capacities. Five CSIRO lead authors of the IPCC report share some practical ways Australians can adapt.
What is adaptation?
“The external environment in which we are operating has changed. The average temperatures and rainfalls have changed, and in some circumstances that warrants a change in our goals and also the way we achieve those goals,” says CSIRO scientist and IPCC report veteran Dr Mark Howden.
“It’s changing what we do to get what we want.”
Adaptation is the process of adjusting those goals and developing strategies to help reduce the impacts of climate change on ecosystems and communities.
“In most cases, there is still a range of options that people can pursue,” he says.
Helping farmers adapt to drier conditions
Dr Howden is a lead author on the food security chapter, a contributing author on the Australasian chapter, and part of the IPCC Synthesis Report core writing team. As an expert on climate change and agriculture, he works with rural industries to help them adapt to Australia’s changing climate.
“There’s evidence that the changes we’ve already seen in terms of climate change are having impacts on food production and food security, and that these changes are likely to increase very significantly over the next decade,” he says.
Adaptation strategies can take place in different forms. Incremental adaptation involves minor adjustments, such as changes to crop variety for hotter conditions. Then there are a series of systemic changes. For instance, reductions in rainfall make conditions more marginal for cropping but more appropriate for grazing. So integrating grazing with cropping is another strategy.
More transformational change involves swapping from a cropping system entirely to a grazing system, or moving to a different environment to continue cropping. Dr Howden says an example of this could be a farmer in Murrumbidgee in south-east Australia moving to the Northern Territory to grow rice.
Farmers have a history of adapting to change. And with climate variability, more flexible farming systems are likely to be an advantage.
Managing water supplies
Dr Francis Chiew is a CSIRO scientist and water expert, and lead author on the Australasian chapter.
“One of the biggest things we need to respond to is the drying trend in Australia,” he says. “The drying trend that we’ve seen in the far south-west and south-eastern Australia is associated mainly with a drier winter, when most of the runoff in southern Australia occurs.”
Dr Chiew says freshwater resources in far south-eastern and south-west Australia are projected to decline by up to 40 per cent and between 20 per cent and 70 per cent respectively, because of a decline in winter rainfall. The range is large mainly because of uncertainties in future rainfall projections.
The CSIRO is providing water agencies with sophisticated climate and water modelling, to help them develop water management options.
Adaptation in cities focuses on securing new supplies that are more resilient to climate shocks, increasing the use of alternative sources like sewerage recycling and storm water for non-potable water, and incentives to reduce water use.
In rural areas, water reforms include purchasing water entitlements for environmental use, upgrading water infrastructure, improving water use efficiency, allocation and trading, and developing flexible water sharing and management plans.
“Although these adaptation measures are driven by climate change, they are also driven by other factors like population growth in cities and equitable sharing of water between irrigation and the environment in regional areas” Dr Chiew says.
Preserving the ocean and ecosystems
CSIRO scientist Dr Elvira Poloczanska is a lead author on the ocean chapter. She says the ocean is very important for human welfare, through the provision and transportation of food and other resources, and providing cultural and economic benefits. The ocean also provides vital services such as regulation of atmospheric gases and the distribution of heat across the planet. But more than 90 per cent of the extra energy from the enhanced greenhouse effect and 30 per cent of anthropogenic carbon dioxide has been absorbed by the ocean, resulting in warming and ocean acidification. This will have significant impacts on ecosystems and coastal communities.
Dr Poloczanska says the CSIRO has partnerships with various organisations and industries, to explore adaptation activities – such as building ecological resilience, as well as providing vulnerability and risk assessments. “We’re actually providing a range of tools across ecology, social and economic systems, so we can fully explore the outcomes of different activities,” she says.
Dr Penny Whetton, a CSIRO scientist who was another lead author on the report’s Australasian chapter, says natural ecosystems have already had to adapt to changing climates. As the climate warms, plants and animals find that their preferred climatic conditions may no longer occur where they are living. So they have to migrate to find conditions they are more accustomed to.
Adaptive responses for ecosystems can be difficult. For instance, Dr Whetton says, a warming of one and a half degrees in the next 30 to 40 years poses a risk to coral reefs that could significantly change their structure.
The changing climate will likely affect fishing, too. “People wanting to catch fish may not find them in locations where they previously occurred,” Dr Poloczanska says. “So if they want to maintain fisheries in that region they may need to change what they fish for.”
Dr Howden adds that in the oceans off south-east Australia, many species from further north are appearing in Tasmanian waters. This is anticipated to increase in the future. One adaptation option, he says, is to ensure that fishery jurisdictions and catch quotas migrate with the fish.
Protecting coastal communities
CSIRO scientist Dr Kathleen McInnes is a lead author of the chapter on coastal systems and low lying areas, and a contributing author to the Australasian chapter. Her work is on the impacts of rising sea levels, ocean warming and ocean acidity.
Dr McInnes says despite efforts to mitigate future greenhouse emissions, sea levels will continue rising for centuries because of warming from previous emissions.
“Protective sea walls may be necessary in the long run if certain sea level rise thresholds are exceeded,” she says.
Until that point is reached, more environmentally-friendly and less costly adaptation measures may include land-use planning to increase and/or maintain a vegetated coastal margin, which serves as a buffer zone against extreme sea levels.
Dr McInnes and her team have been modelling extreme sea levels around the Australian coastline to better understand how changes to weather patterns may alter extreme sea level risk in the future.
“We are finding that for most regions, it is the sea level rise that will be the dominant factor for worsening the impact of storm surges in the future. However changing weather patterns will also play a role in some places” she says.
Previously, her team has used modelling to develop inundation maps, which can be used to identify areas that are most vulnerable to rising sea levels. Such maps provide information about where adaption planning in the coastal zone is most needed.
What’s coming up?
The CSIRO has played a leading role in providing Australian climate change projections for 20 years, to help with adaptation planning. Dr Whetton is part of a team now using the latest global climate model experiments from all the modelling centres around the world to provide updated climate change projections for Australia. This work is expected to be completed this year.
The climate projections aim to help support the needs of natural resource management, at regional level.
The projections will take into account multiple variables including temperature, precipitation, humidity, radiation and sea level. Extremes like very hot days and extreme rainfall will be assessed.
“As well as being updated with the latest science, expect these projections to be the most comprehensive yet produced for Australia, and very well-tailored for application in a broad range of impact areas,” Dr Whetton says.