THIRSTY COUNTRY: CLIMATE CHANGE AND IN

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CLIMATECOUNCIL.ORG.AU Authorship: Will Steffen

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Professor Will Steffen Climate Councillor Key Findings:

1. Climate change is likely 2. have far-reaching making drought conditions impacts on health, agriculture in southwest and southeast and native species in Australia. Australia worse. ›› The relative risk of suicide can ›› Fronts from the Southern Ocean, increase by up to 15 percent for which typically bring rain across rural males aged 30-49 as the southern Australia during severity of drought increases. winter and spring, have shifted ›› Between 2002 and 2003 decreases southwards with a warming in agricultural production due to climate, leading to declines in drought resulted in a 1 percent fall rainfall in southwest and southeast in the Gross Domestic Product Australia and increasing the risk (GDP), which is equivalent to half of drought conditions in of Australia’s decline in annual these regions. GDP following the global financial ›› Since the mid-1990s, southeast crisis in 2009. Australia has experienced a 15 percent decline in the late autumn and early winter rainfall and a 25 percent decline in average rainfall in April and May. ›› Average annual stream flow into Perth’s dams has already decreased by nearly 80 percent since the mid-1970s. ›› Climate change is driving an increase in the intensity and frequency of hot days and heatwaves in Australia, in turn increasing the severity of droughts.

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3. will become 4. Droughts are likely to worsen an increasing challenge as in severity and duration the pressure on urban water in southern Australia if supplies intensifies. greenhouse gas emissions are not cut deeply and rapidly. ›› Water inflows to key dams such as Warragamba and ›› Average rainfall in southern Shoalhaven could decrease by as Australia during the cool season much as 25 percent by 2070 if is expected to decline further, greenhouse gas emissions continue and the time spent in drought on their current trajectory. conditions is projected to increase. ›› Annual water demand is projected ›› In total to outstrip supply in Perth and reductions in autumn and winter surrounding regions by as much precipitation could be potentially as 85 billion litres by 2030. That’s as high as 50 percent in the next enough water to fill 34,000 Olympic 80 years. sized swimming pools. ›› To stabilise the climate, we must ›› Average annual stream flows to rapidly reduce greenhouse gas ’s four major water emissions, increase investment harvesting storages could decrease in clean energy, and most of the by seven percent by 2020 and by world’s fossil fuel reserves – coal, 18 percent by 2050. oil and gas - must remain in the ground.

Page ii CLIMATECOUNCIL.ORG.AU Introduction

Drought has deeply affected Australia We begin this report by describing throughout its history. The Millennium what a drought is, before considering Drought from 1996-2010 serves as a its consequences for health, the recent reminder of the wide-reaching economy, ecosystems and urban water impacts that drought can have on supplies. We then outline the changing Australia’s people and environment. drought conditions and increasing drying trends in Australia and explore Australia is the driest inhabited continent recent dry conditions in various parts of on Earth and drought is an important the country. We conclude by exploring feature of Australia’s climate. Whilst how climate change is influencing Australians have always lived with drought conditions in the southeast drought and its consequences, it is likely and southwest of the continent as well that climate change is making drought as drying trends globally. worse in the southeast and southwest, some of our most populous regions.

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1. What is a drought?

Australia is the driest inhabited continent which is measured through deficits on Earth, with some of the world’s most in soil moisture, and hydrological variable rainfall and stream-flow (DFAT drought, which is based on anomalies 2014). The country has been deeply in stream flow, lake and/or groundwater affected by drought throughout history, levels (IPCC 2012). Both of these with significant droughts such as the definitions are important in terms of (1895–1903), which understanding the impacts of drought, led to the loss of millions of cattle, and and the consequences of climate the World War II drought (1939–1945), change for these impacts. which contributed to plummeting wheat As outlined by the Intergovernmental yields and disastrous bushfires (BoM Panel on Climate Change (IPCC), ‘climate 2014a; 2014b). The ‘Big Dry’ of 1996–2010 extremes, such as drought, may be the (also called the Millennium Drought) result of an accumulation of weather went down in history as one of the worst or climate events that are not extreme droughts on record for Australia, with when considered independently’ (IPCC devastating impacts (van Dijk et al. 2013). 2012, p.7). In Australia, the Bureau of Drought can be defined in a variety of Meteorology (BoM) measures drought different ways. In terms of its links to by monitoring ‘serious’ or ‘severe’ rainfall climate change, drought is best defined deficiencies that have occurred for three as meteorological drought, which is months or more. A rainfall deficiency ‘a prolonged, abnormally dry period is considered ‘serious’ when rainfall is when the amount of available water is in the lowest 5-10 percent of the full insufficient to meet our normal use’ range of rainfall amounts, from the very and is generally measured by assessing lowest to the very highest, for the period rainfall deficiencies over three or more measured, and ‘severe’ when rainfall is months (BoM 2014c). in the lowest 0-5 percent of the range. Whilst BoM tracks rainfall deficiencies, In addition to meteorological drought, it is the responsibility of the State and/or two other definitions of drought are Federal Governments to officially declare used by different economic sectors or a drought (BoM 2012). areas of research: agricultural drought,

Page 2 CLIMATECOUNCIL.ORG.AU 2. What are the consequences of drought?

Drought has significant impacts on “Drought can contribute to health, the economy, ecosystems and urban water supplies. declines in human health and increases in mortality rates.” “The World Meteorological Organization has linked found that the relative risk of suicide can increase by up to 15 percent for rural drought to 680,000 deaths males aged 30–49 as the severity of globally from 1970–2012.” drought increases (Hanigan et al. 2012). 2.2 Economic 2.1 Health Drought affects agriculture, tourism, Droughts can have wide ranging effects employment and livelihoods in Australia, on health including on nutrition, with severe economic repercussions. infectious diseases, on forest fires Between 2002 and 2003 decreases in causing air pollution, and mental health agricultural production due to drought problems, such as post-traumatic resulted in a 1% reduction in the Gross stress and suicidal behaviour (Haines Domestic Product (GDP) and a 28.5% et al 2006; Climate Commission fall in the gross value added for the 2011). Droughts can also contribute to agricultural industry compared to increases in mortality rates. The World the preceding year (ABS 2004). This Meteorological Organization (WMO) has is a significant hit to the economy, linked drought to 680,000 deaths globally considering that the global financial from 1970–2012 (WMO 2014). Declines crisis caused a reduction of 2 percent in physical health are also particularly in Australia’s annual GDP from 2008 to prevalent amongst the elderly in drought 2009 (World Bank 2015). The predicted affected rural communities in Australia increase in drought frequency in the (Horton et al. 2010). Furthermore, future has been estimated to cost drought can play a role in exacerbating $5.4 billion annually, reducing GDP by mental health issues and increasing 1 percent per annum (Carroll et al 2007). suicide rates in Australian drought- Several important agricultural areas, affected rural populations, especially including southwest Western Australia, amongst male farmers (Alston 2012). parts of central and A recent study in (NSW)

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northern New South Wales, More recently the Millennium Drought and southern , and most in southeast Australia, which lasted of , received below-average from 1996 to 2010, was one of the worst annual rainfall for 2014 (BoM 2015a). on record for the region (van Dijk et al. Significantly reduced rainfall in winter 2013). Southeast Australia experienced its and spring across eastern Australia lowest 13-year rainfall record since 1865 affects the intensive cropping and (CSIRO 2012). The Millennium Drought livestock breeding that is commonly had wide-ranging repercussions. For practiced in the region, with potentially example agricultural production fell serious economic repercussions from 2.9 percent to 2.4 percent of Gross (ABARES 2012). Domestic Product (GDP) between 2002 to 2009, with drought playing a significant Particularly noteworthy droughts in role in these observed declines in GDP recent history include the period from (van Dijk et al. 2013). It is estimated that 1982–1983 when Australia experienced between 2006 and 2009 the drought one of the most intense droughts on reduced national GDP by roughly 0.75 record, with a total loss of $3 billion in percent. Between 2007-2008 regional agricultural production alone (ABARES GDP in the southern Murray-Darling 2012). The Wimmera Southern Mallee Basin fell 5.7 percent below forecast and region of Victoria experienced an was accompanied by the temporary loss 80 percent reduction in grain production of 6000 jobs (IPCC 2014). and a 40 percent reduction in livestock production (BCG 2008).

Figure 1: Cows in drought stricken fields, NSW

Page 4 CLIMATECOUNCIL.ORG.AU “By mid-2010 the Australian government had paid $4.4 billion in direct drought assistance to farmers.”

Drought can also be costly due to 2.3 Ecosystems drought relief packages provided by the federal government. By mid-2010 the Drought has significant impacts on Australian government had paid $4.4 Australia’s natural environment. For billion in direct drought assistance to example, aquatic ecosystems are often farmers (ABARES 2012). Drought also has affected by drought, with decreased economic repercussions for Australia’s water supplies reducing the availability tourism industry. In the Murray River of suitable habitat and leading to region, it is estimated that the drought reductions in the populations of many caused an estimated $70 million loss fish and invertebrate species and, because of reduced visitor days in 2008 in some cases, contributing to local (TRA 2010). A recent report by the WMO extinctions (Bond et al. 2008). During the estimated that the impacts of Australia’s Millennium Drought, there was a marked 1981 drought cost US$ 15.15 billion and decline in water bird, fish and aquatic was Australia’s most costly weather- plant populations in the Murray-Darling related event (WMO 2014). Basin (LeBlanc et al. 2012).

Figure 2: Dead trees, South Australia

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Many terrestrial ecosystems are also “Many thousands of plants affected by drought, with iconic species such as the river red gum dying over and animals could be at extensive areas in the Murray-Darling Basin (Bond et al. 2008). The factors risk if the rate of climate leading to the decline and death of these change continues” trees, many of which are several hundred years old, suggest that the circumstances 2.4 Urban water supplies that led to their decline are ‘beyond natural conditions’ (LeBlanc et al. 2012 Water scarcity in major cities, particularly p.236). Melbourne, Sydney and Perth, has been exacerbated by drought and remains Severe heatwaves and drought are also an ongoing challenge. As of 2013, one of the biggest threats to native 89 percent of Australia’s population lived eucalyptus species (Butt et al. 2013). in urban areas (World Bank 2013), placing Drought also poses risks to planted high demand on urban water supplies as forests. During the Millennium Drought, populations continue to grow. Pressure for example, 57,000 ha of planted forest on urban water supplies is projected in Australia were lost (van Dijk et al. to intensify as droughts increase in 2013). This is equivalent to the area of frequency and severity in the southwest 28,500 cricket pitches. and southeast (Collett and Henry 2011). “During the Millennium Drought can significantly reduce inflows into vital urban water catchments, as Drought 57,000 ha of planted occurred during the Millennium Drought forest in Australia were lost. (Section 3), resulting in water restrictions. For example, from 2007–2010 Melbourne This is equivalent to the area was placed on Stage 3 restrictions and in 2009 Melbourne’s water storage levels of 28,500 cricket pitches.“ fell to a record minimum of 25.6 percent (Melbourne Water 2013; Melbourne Water As the trend towards hotter, drier 2014). conditions continues in southern Australia (Section 3), native species will Industries also had to adhere to water continue to face habitat degradation, restrictions, with the agricultural sector population declines, and in some cases particularly affected by water scarcity extinction (Reisinger et al. 2014). If the and a resulting decline in crop yields rate of climate change that the continent (Grant et al. 2013; Melbourne Water is currently experiencing continues, 2014). Similarly, during the Millennium many thousands of terrestrial and Drought in southeast Queensland severe freshwater species could be at risk, such water restrictions were implemented as the green and golden bell frog, the that saw average water use in some platypus and a variety of eucalypt forests areas fall to 129 litres per person per (MacNally et al. 2009; Klamt et al. 2011; IPCC 2014; Climate Council 2014a).

Page 6 CLIMATECOUNCIL.ORG.AU day, in comparison to a regional urban A study by Melbourne Water projects consumption of 375 litres under normal that under ‘medium’ climate change operating conditions (Queensland Water scenarios a potential seven percent Commission 2010). decrease in average annual stream flows to Melbourne’s four major water Assessments of future impacts of harvesting storages could be expected drought on both water supply and urban by 2020 and 18 percent by 2050 (Howe water demand at the regional and/ et al. 2005). or catchment level suggest that water scarcity could increase across Australia. In NSW, under a high emissions scenario “Water scarcity could along with high population growth and increase across Australia” less rapid technological change (IPCC 2000), water inflows to key Sydney dams The projected increase in duration such as Warragamba and Shoalhaven and intensity of droughts in southeast could decrease by as much as 25 Queensland (CSIRO and BoM 2015; percent by 2070 (NSW Office of Water Section 3) is expected to increase the 2010). These declines, coupled with a length of time it takes to refill key water continued rise in annual demand for storages in the region. An assessment drinking water in the residential and of climate change impacts on water commercial sectors, could increase the availability in Moreton catchment has imposition of water restrictions in the found a decline in inflow into water state (NSW Office of Water 2010).

Figure 3: Recycling water in Melbourne

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storages when it rains, and longer breaks this into context, Western Australia’s between significant ‘storage filling Integrated Water Supply Scheme (IWSS) events’ (UWSRA 2011). currently delivers 289 billion litres of water to over 2 million people in the Finally, the pronounced drying trend region each year. A deficit of 85 billion over southwest Australia, which is litres is equivalent to approximately projected to continue throughout the 30% of current water supply (WA Water 21st century (Section 3), has significant Corporation 2014). That’s enough water implications for urban water supplies to fill 34,000 Olympic sized swimming in Perth (Collett and Henry 2011). The pools. Desalination plants, which Western Australia Department of Water have been built in all mainland states (2009) predicts a supply-demand annual in Australia, can potentially assist in deficit that is potentially as large as easing declines in urban water supplies, 85 billion litres by 2030 for the Perth, although they have significantly varied goldfields and agricultural regions and water-producing capacity (Hoang et al. some parts of the southwest. To put 2012).

Figure 4: Lake Hume during drought in 2007, Victoria

Page 8 CLIMATECOUNCIL.ORG.AU 3. What changes have been observed in drought conditions in Australia?

Whilst some parts of Australia are getting wetter, particularly the northwest of the continent, some of the most populous and agriculturally productive regions in the south are becoming drier (CSIRO and BoM 2014; Figure 5).

Southern wet season (April-November) rainfall deciles since 1996. A decile map shows the extent that rainfall is above average, average, or below average from the specified time period, in comparison with the entire national rainfall record from 1900. The southern wet season is defined as April to November by the Bureau of Meteorology

Northern wet season (October-August) rainfall deciles since 1995–6. A decile map shows the extent that rainfall is above average, average, or below average from the specified time period, in comparison with the entire national rainfall record from 1900. The northern wet season is defined as October to April by the Bureau of Meteorology

Figure 5: Long term changes in rainfall across Australia. Source: (CSIRO and BoM 2014)

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A long-term drying trend is particularly need to increase the capacity of the state’s evident in the southwest and southeast desalination plants, or find alternate of Australia, with rainfall deficiencies sources of water in order to sustain the and declines in soil moisture indicative population of the city (The Guardian 2014). of dry conditions that have persisted in The drying trend in the southeast of recent decades (CSIRO and BoM 2015). In Australia is evidenced by declines in the southwest, rainfall has declined since rainfall combined with increases in the mid-1970s. This drying trend has temperature. Since the mid-1990s, been particularly severe in the southwest southeast Australia has experienced a corner of Western Australia, which has 15 percent decline in late autumn and experienced a 15 percent drop in rainfall early winter rainfall and a 25 percent since the mid‑1970s (WC 2012; Climate decline in average rainfall in April Commission 2013). and May (CSIRO and BoM 2014). The Future drying trends in Australia are region has also experienced significant projected to be most pronounced over warming during the last 50 years southwest Western Australia, with (Timbal et al. 2010). The warming trend total reductions in autumn and winter was especially prominent in 2013 with precipitation potentially as high as 50 two intense and prolonged heatwaves percent by the late 21st century (Delworth affecting the southeast in early January and Zeng 2014; CSIRO and BoM 2015). and March 2013 (BoM 2013). This could have significant implications for the city of Perth, which has already The combination of dry and hot experienced a reduction of nearly 80% conditions was particularly severe in total annual inflow into its dams since in Australia during the Millennium the mid-1970s (Figure 6). The city may Drought, which was concentrated in

900 Annual Total 800 1911-1974 av (338 GL) 700 1975-2000 av (177 GL) 2001-05 av (92.7 GL) 600 2006-12 av (65.8 GL)

500

400

300

2012 Total Annual ‘Inflow to Perth Dams’ (GL) Dams’ Perth to ‘Inflow Annual Total 200 (18.3 GL)

100 1951 1911 1913 1915 1917 1919 1921 1923 1925 1927 1929 1931 1933 1935 1937 1939 1941 1943 1945 1947 1949 1953 1955 1957 1959 1961 1963 1965 1967 1969 1971 1973 1975 1977 1979 1981 1983 1985 1987 1989 1991 1993 1995 1997 1999 2001 2003 2005 2007 2009 2011

!"#$%&FigureFigure 6: 20: Trend Trend in in totaltotal annualannual stream stream flow flow into intoPerth Perthdams 1911-2012dams 1911–2012. Source: (Climate ! " '$()*+%*#(,$-*(%*.('*#"*/0)+1*(-2*1(3$11$2*'$()*+%*%#()#*45+-#$)6*"7*'$() 1(#$%#*:02(#$*H#<*!"I$93$)*=>?= !!Commission" Source:8- "5*+%*%+9:1(#$2*3(%$2*"-*;$)#<*2(9%*+-*=>>?*+@$@*$AB1:2+-C*D#+)1+-CE*D(9%"- WC, 20122013) G*",(1:0F* D":)B$&*G /E*=>?=

Page 10 CLIMATECOUNCIL.ORG.AU Australia’s south and was exceptional for It will likely be increasingly difficult to both its length and its severity (CSIRO erase such rainfall deficits in future, 2012; CSIRO and BoM 2015). During this with further declines in average rainfall drought, average annual rainfall was projected for southern Australia in the 12 percent below the long‑term (1990– cool season (winter and spring), mainly 2010) average of 582 mm, the lowest ever driven by the southward movement 13-year rainfall period was recorded, of winter storm systems. There are no and there was an absence of ‘wet years’ reliable predictions yet for the direction and ‘very wet months’ (CSIRO 2012). of change in rainfall in summer and The decreases in cumulative rainfall autumn (CSIRO and BoM 2015). during therainfall Millennium to erase Droughtthe deficit (Figure created by long droughts. It will likely be increasingly 7) showdifficult that it takes to erase several such years rainfall of deficits in future, with below average rainfall projected above-averageto persist rainfall across to south eraseeastern the deficit Australia towards the end of autumn and into the winter created monby longths eachdroughts. year (CSIRO 2012).

FigureFigure 7: 7:Cumulative Cumulative rainfall rainfall variation variation (in (inmm) mm) from from the thelong-term long-term average average for forsoutheast southeast AustraliaAustralia for for the the period period January January 1997 1997 to Decemberto December 2011. 2011. Individual Individual monthly monthly variations variations are shownare shown in the in columns. the columns. Source: Source: (Climate (Climate Commission Commission 2013, 2013a,adapted adapted from BoM) from BoM).

Whilst rainfall deficiencies are a key measure for meteorological drought, soil moisture is also an insightful indicator, with the physical impacts of severe droughts continuing long after the rainfall has returned as soil moisture can remain severely depleted (ABARES 2012). Some studies that use soil moisture rather than rainfall CLIMATECOUNCIL.ORG.AUdeficiency to assess dryness across Australia have also identified a potential dryingPage 11 pattern in some regions of the country. This is particularly evident in the more populous eastern half of the continent, although some other areas have also experienced decreases in drying, such as central Australia (IPCC 2012). Long-term trends in soil moisture across the soil profile also point to a possible drying trend in some regions (CSIRO 2014).

In Australia, drought has currently been declared in parts of Queensland, with serious to severe rainfall deficiencies for the 24-month period in northern NSW, parts of the , South Australia, much of inland western Victoria and Queensland (BoM 2014b). Looking to the medium term, serious or severe rainfall deficiencies for

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Whilst rainfall deficiencies are a key deficiencies in Queensland can largely be measure for meteorological drought, attributed to below-average rainfall over soil moisture is also an insightful the 2013–14 and 2012–13 ‘summer’ wet indicator, with the physical impacts of seasons (the northern wet season spans severe droughts continuing long after October–April) (BoM 2015b). Drought the rainfall has returned because soil conditions are expected to persist, moisture can remain severely depleted particularly in Queensland and western (ABARES 2012). Some studies that use soil Victoria (BoM 2015c). moisture rather than rainfall deficiency to assess dryness across Australia “In March 2014, 75% of have also identified a potential drying pattern in some regions of the country. Queensland was declared This is particularly evident in the more in drought” populous eastern half of the continent, although some other areas have also In March 2014, 50 local government experienced decreases in drying, such areas in Queensland (75 percent of the as central Australia (IPCC 2012). Long- state) were declared in drought, making term trends in soil moisture down the it the largest area of Queensland to ever soil profile also point to a possible drying be declared in drought (DAFF 2014; ABC trend in some regions (CSIRO 2014). 2014a; ABC 2014b). In February 2015, In Australia, between October 2012 the number of drought-declared local and February 2015, rainfall deficiencies government areas decreased slightly to increased across central northern 44, which remains a significant portion Queensland south of the Cape York of the state (DAFF 2015). Peninsula, extending through inland Whilst the NSW state government no southern Queensland to northern New longer issues drought declarations, South Wales inland of the Great Dividing the NSW government’s February 2015 Range, and in the area covering western seasonal condition report indicates Victoria and adjacent southeastern South that portions of the state have been Australia. impacted by severe rainfall deficiencies. Severe and serious deficiencies are For example, severe rainfall deficiencies happening in these areas and in small occurred across the northwest and areas of southwestern Queensland during the last and adjacent parts of the southeastern 24 months and drier than normal Northern Territory and northeastern conditions are expected to continue South Australia, pockets to the east of between February and April 2015 (DPI in southern New South Wales 2015). and around the northeast of Melbourne The long-term drying trend in the in Victoria, and in small parts of coastal southeast is exacerbated from time to western Tasmania. Long-term rainfall time by the occurrence of El Niño events,

Page 12 CLIMATECOUNCIL.ORG.AU a feature of natural climate variability The Millennium Drought, one of the that recurs about every three to eight most severe droughts on record, was years (BoM 2005). El Niño events in exacerbated by two separate El Niño Australia are often associated with below events (ABARES 2012). At present, while average rainfall in winter and spring, the tropical Pacific Ocean is in neutral particularly across eastern Australia conditions, the likelihood of an El Niño (BoM 2010; ABARES 2012) and above developing in 2015 has increased. average temperatures (Arblaster and Therefore, the ENSO Tracker status has Alexander 2012). recently been raised to El Niño ‘WATCH’ (BoM 2015d).

Figure 8: Dry paddocks near Junee, NSW

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Trends in heat also play a role in the impacts of Australia’s Millennium exacerbating the severity of drought. Drought were exacerbated by extreme The relationship between drought heat, with temperatures 0.3–0.6°C above and heat is often one of mutual the long-term average (Head et al. 2013). reinforcement; the reduced soil moisture Australia’s climate has continued to associated with drought contributes warm over the last century and 2013 to rises in air temperature, and in turn was Australia’s warmest year on record these hotter conditions further increase (BoM and CSIRO 2013). In addition, hot loss of soil moisture (Climate Council extremes are becoming more frequent 2014b). For example, it is likely that and intense (IPCC 2014).

Figure 9: A sheep grazes in a dry paddock in Victoria, 2008

Page 14 CLIMATECOUNCIL.ORG.AU 4. How is Climate Change Influencing Drought?

Climate change is exacerbating drought have increased as a result of increasing conditions in Australia through changes greenhouse gas concentrations (Timbal in rainfall patterns and increasing and Drosdowsky 2012; CSIRO 2012). The heat. In the future severe droughts are intensification of the STR is estimated expected to happen more often. to account for roughly 80 percent of the recent rainfall decline in southeast The evidence for the influence of climate Australia (Murphy and Timbal 2008; change on observed drought patterns Climate Commission 2013). is strongest for southwest Western Australia and the far southeast of the The observed drying trends during the continent - Victoria and southern parts cooler months in the southwest and of South Australia (CSIRO 2012). The southeast of the continent, which are link is related to the southward shift of likely influenced by climate change the fronts from the Southern Ocean that already, are expected to continue. bring rain across southern Australia Average rainfall in southern Australia during the cool months of the year during the cool season is expected to (winter and spring) (CSIRO and BoM decline further, and the time spent in 2015). This shift, which is consistent with drought conditions is projected to the changes in patterns of atmospheric increase with a greater frequency of circulation expected in a warming severe droughts in the region (CSIRO climate system, has led to the observed and BoM 2015). declines in rainfall in the southwest The ongoing drying trend and projected and southeast of the continent and the increase in severe droughts could lead resulting drought conditions (Timbal and to decreases in production in Australia’s Drowdowsky 2012; Climate Commission most important agricultural regions, 2013). including the largest catchment and As part of the changes in atmospheric most productive agricultural area in the circulation, the subtropical ridge (STR), country, the Murray-Darling basin, and an area of high pressure that commonly southwest wheat belt (IPCC 2014). The lies over the Australian continent, has projected drying trend across southern intensified as global air temperatures Australia could also threaten urban water

“In parts of Southern Australia severe droughts are expected to continue. ”

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supplies, as nearly 13 million of Australia’s (IPCC 2013; IPCC 2014; CSIRO and BoM population is concentrated in the southern 2015), which in turn contributes to an cities of Perth, Adelaide, Melbourne, increase in the severity of droughts Canberra and Sydney (ABS 2014). (Climate Commission 2013). Since 2001, the number of extreme heat records Climate change is also contributing to an in Australia has outnumbered extreme increase in the intensity and frequency cool records by almost 3 to 1 for daytime of hot days and heatwaves in Australia

Change in consecutive dry days (CDD) Soil moisture anomalies (SMA) 2046 - 2065 2046 - 2065

2081 - 2100 2081 - 2100

− Dryness + + Dryness −

-0.6 -0.4 -0.2 0 0.2 0.4 0.6 -0.75 -0.50 -0.25 0 0.25 0.50 0.75 Standard Deviation Standard Deviation

Figure 10: Projected annual changes assessed from two indices. Left column: Change in annual maximum number of consecutive dry days (CDD: days with precipitation <1 mm). Right column: Changes in soil moisture (soil moisture anomalies, SMA). Increased dryness is indicated with yellow to red colours; decreased dryness with green to blue. Projected changes are expressed in units of standard deviation of the interannual variability in the three 20-year periods 1980–1999, 2046–2065, and 2081–2100. The figures show changes for two time horizons, 2046–2065 and 2081–2100, as compared to late 20th-century values (1980–1999), based on GCM simulations under emissions scenario SRES A2 relative to corresponding sumulations for late 20th century. Results are based on 17 (CDD) and 15 (SMA) GCMs contributing to the CMIP3. Coloured shading is applied for areas where at least 66% (12 our of 17 for CDD, 10 out of 15 for SMA) of the models agree on the sign of the change; stippling is added for regions where at least 90% (16 out of 17 for CDD, 14 our of 15 for SMA) of all models agree on the sign of the change. Grey shading indicates where there is insufficient model agreement (<66%). (IPCC 2012)

Page 16 CLIMATECOUNCIL.ORG.AU maximum temperatures and almost 5 to Finally, on a global scale, whilst it is 1 for night-time minimum temperatures likely that some regions of the planet (CSIRO and BoM 2015). Australia’s capital will become increasingly wetter, others cities have experienced hotter, longer or are likely to experience drier conditions more frequent heatwaves. For example, as measured by consecutive dry days the average intensity of heatwaves in and decreases in soil moisture (Figure Melbourne is now 1.5 °C hotter and they 10). Consistent with the CSIRO and BoM occur on average 17 days earlier than analysis (2015), southern Australia is one between 1950 and 1980. Whilst in Sydney, of the regions that is likely to become heatwaves now start 19 days earlier drier through the century, with some and the number of heatwave days has other regions, such as the Mediterranean increased by 50% (Perkins and Alexander and southern Africa, expected to 2013). The IPCC warns that it is very experience particularly severe likely (over 90 percent probability) that drying trends (IPCC 2012). warm days will increase and cold days will decrease in Australia (IPCC 2012). In addition, it is likely that more frequent and/or longer heatwaves and warm spells will occur across the continent (IPCC 2012). These projected increases in heat will compound existing drought conditions in Australia.

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5. This is the Critical Decade

The impacts of climate change are Societies will have to adapt to even more already being observed. Sea levels are serious impacts as the temperature rises. rising, heatwaves are increasing in For Australia, these impacts include length and intensity, and southern increases in the severity of drought in Australia is experiencing a long-term the south, with implications for human drying trend. health, agriculture, urban water supplies and the environment. Ensuring that the We are now more confident than ever 2°C guardrail is not exceeded will prevent that the emission of greenhouse gases even worse impacts in the second half of by human activities, mainly carbon the century. dioxide from the combustion of fossil fuels, is the primary cause for many of The evidence is clear and compelling. the changes in climate that have been To stabilise the climate, the trend of observed over the past half-century increasing global emissions must be (IPCC 2013; 2014). Projections of future halted within the next few years and climate change and its impacts have emissions must be trending downwards convinced nations that the global by 2020. Investment in renewable, clean average temperature, now at 0.85°C energy must therefore increase rapidly. above the pre-industrial level (IPCC And, importantly, most of the known 2013), must not be allowed to rise above fossil fuel reserves - coal, oil and gas - 2°C, the so-called ‘2°C guardrail’. must remain in the ground. This is the critical decade to get on with the job.

Page 18 CLIMATECOUNCIL.ORG.AU References

ABC (Australian Broadcasting Corporation) BoM (2012) Climate Glossary: Drought. Bureau of (2014a) Queensland farmers told to expect ‘tough Meteorology. Accessed at http://www.bom.gov.au/ times’ as drought conditions expected to worsen. climate/glossary/drought.shtml. 11 July 2014. Accessed at http://www.abc.net.au/ BoM (2013) Annual Climate Report 2013. Bureau news/2014-07-11/qld-farmers-told-to-brace-for- of Meteorology. Accessed at http://www.bom.gov. tough-times/5589468. au/climate/annual_sum/2013/AnClimSum2013_ ABC (2014b) How severe is the drought in LR1.0.pdf. Queensland and New South Wales? 18 March 2014. BoM (2014a) The Federation Drought 1895–1902. Accessed at http://www.abc.net.au/news/ Bureau of Meteorology. Accessed at http://www. 2014-03-12/tony-abbott-drought-severity- bom.gov.au/lam/climate/levelthree/c20thc/ claim-checks-out/5295232. drought1.htm. ABARES (Australian Bureau of Agricultural and BoM (2014b) The World War II Droughts. Bureau of Resource Economics and Sciences) (2012) Drought Meteorology. Accessed at http://www.bom.gov.au/ in Australia: context, policy and management. lam/climate/levelthree/c20thc/drought3.htm. Canberra: ABARES report to client. Accessed at http://www.daff.gov.au/SiteCollectionDocuments/ BoM (2014c) Rainfall Deficiencies: what is a abares/publications/clientreports/Drought_in_ drought? Bureau of Meteorology. Accessed at Australia_2012.pdf. http://www.bom.gov.au/climate/drought/. ABARES (2014) Australian Crop Report: BoM (2014d) Drought Statement: rainfall September 2014. Canberra. Accessed at: deficiencies worsen in Victoria and Tasmania. http://data.daff.gov.au/data/warehouse/ Bureau of Meteorology. Accessed at http://www. aucrpd9abcc003/aucrpd9abcc201409/ bom.gov.au/climate/drought/#tabs=Drought- AustCropRrt20140909_v1.0.0.pdf. Statement. ABS (Australian Bureau of Statistics) (2004) Yearbook BoM (2014e) Climate outlook for October to Australia 2004—Economic Impact of Drought in December: 25 September 2014. Bureau of 2002-03. Canberra, Australia: Australian Bureau of Meteorology. Accessed at http://www.bom.gov.au/ Statistics; 2004. Accessed at http://www.abs.gov.au/ climate/ahead/archive/outlooks/latest-outlook.shtml. ausstats/[email protected]/0/81A2E2F13AA7994BCA256DEA 00053932?opendocument. BoM (2015a) National Climate and Water Briefing, 29 January 2015. ABS (2014) Regional Population Growth, Australia, 2012–13. The Australian Bureau of Statistics. BoM (2015b) Drought Statement updated on 4 Accessed at http://www.abs.gov.au/ausstats/abs@. March 2015. Accessed at http://www.bom.gov.au/ nsf/Products/3218.0~2012-13~Main+Features~ climate/drought/. Australian+Capital+Territory?OpenDocument. BoM (2015c) Climate Outlooks issued 26 February Alston M (2012) Rural male suicide in Australia. 2015. Accessed at http://www.bom.gov.au/climate/ Social Science & Medicine 74:515–522. outlooks/#/overview/summary. Arblaster JM and Alexander LV (2012) The BoM (2015d) ENSO Tracker: Official status of the El Impact of the El Niño-Southern Oscillation Niño–Southern Oscillation. Issued 17 March 2015. on Maximum Temperature Extremes. Accessed at http://www.bom.gov.au/climate/enso/ Geophysical Research Letters 39(20). tracker/. BCG (Birchip Cropping Group) (2008). Critical Bond RN, Lake SP and Arthington HA (2008). The breaking point? The effects of drought and other Impacts of Drought on Freshwater Ecosystems: an pressures on farming families. Final report of the Australian perspective. Hydrobiologia (600): 3–16. twelve month study. Accessed at http://www. Butt N, Pollock L and McAlpine AC (2013) Eucalypts daff.gov.au/__data/assets/pdf_file/0008/842246/ face increasing climate stress. Ecology and Birchip_Cropping_Group.pdf. Evolution (15): 5011–5022. BoM (Bureau of Meteorology) (2005) El Niño, Carroll N, Fritjers P and Shields MA (2007) La Niña and Australia’s Climate. Bureau of Quantifying the costs of drought: new evidence Meteorology. Accessed at http://www.bom.gov.au/ from life satisfaction data. Journal of Population info/leaflets/nino-nina.pdf. Economics 20:445-461. BoM (2010) Australian Rainfall Patterns During Climate Commission (2011) The Critical El Niño Events. Bureau of Meteorology. Accessed Decade: Climate Change and Health. Hughes at http://www.bom.gov.au/climate/enso/nino L and McMichael M. Accessed at https://www. comp.shtml. climatecouncil.org.au/commission-climate- change-and-health.

CLIMATECOUNCIL.ORG.AU Page 19 PARCHED COUNTRY: CLIMATE CHANGE AND DROUGHT IN AUSTRALIA

Climate Commission (2013) The Critical Decade Grant BS, Fletcher DT, Feldman D, Saphores JD, 2013: extreme weather by Will Steffen, Lesley Cook LM, Stewardson M, Low K, Burry K and Hughes and David Karoly. Accessed at https:// Hamilton JA (2013) Adapting Urban Water www.climatecouncil.org.au/extreme-weather- Systems to a Changing Climate: Lessons from report. the Millennium Drought in Southeast Australia. Environmental science & technology 47(19): 10727- Climate Council (2014a) Unpacking the Fifth 10734. Assessment Report: impacts, adaptation and vulnerability by Lesley Hughes. Accessed at Hanigan IC, Butler CD, Kokic PN and Hutchinson https://www.climatecouncil.org.au/ipcc. MF (2012) Suicide and drought in New South Wales, Australia, 1970–2007. Proceedings of the National Climate Council (2014b) Heatwaves: hotter, Academy of Sciences 109:13950–13955. longer, more often by Will Steffen, Lesley Hughes and Sarah Perkins. Accessed at https://www. Haines A, Kovats RS, Campbell-Lendrum D and climatecouncil.org.au/heatwaves-report. Corvalán C (2006) Climate change and human health: Impacts, vulnerability and public health. Collett B and Henry N (2011) Urban Water Supply Public health, 120(7), 585-596. Use. The Australian Collaboration. Accessed at http://www.australiancollaboration.com.au/pdf/ Head L, Adams M, McGregor VH and Toole S FactSheets/Urban-water-FactSheet.pdf. (2013) Climate Change and Australia. WIREs Climate Change, 5: 175–197. CSIRO (The Commonwealth Scientific and Industrial Research Organisation) (2012) Climate and water Hoang M, Bolto B, Haskard C, Barron O, Gray S availability in south-eastern Australia: A synthesis and Greg L (2012) Desalination in Australia Report. of findings from Phase 2 of the South Eastern CSIRO. Accessed at http://www.csiro.au/Portals/ Australian Climate Initiative (SEACI) CSIRO, 41 pp. Publications/Research--Reports/Desalination-In- Australia-Report.aspx. CSIRO (2014) Australian Water Availability Project. CSIRO. Accessed at http://www.eoc.csiro.au/awap/. Horton G, Hanna L and Kelly B (2010) Drought, drying and climate change: Emerging health issues CSIRO and BoM (2014) State of the Climate 2014. for ageing Australians in rural areas. Australasian CSIRO and Bureau of Meteorology, Melbourne. Journal on Ageing 29:2–7. CSIRO and BoM (2015) Climate change in Australia: Howe C, Jones RN, Maheepala S and Rohdes B Projections for Australia’s NRM regions. Technical (2005) Implications of Potential Climate Change Report, 216pp. for Melbourne’s Water Resources. Melbourne DAFF (Department of Agriculture, Fisheries Water. Accessed at http://www.melbournewater. and Forestry) (2014) Drought and Natural com.au/whatwedo/Liveability-and-environment/ Disaster Declaration: 12 September. Queensland Documents/Climate_Change_Study.pdf. Government. Accessed at https://www.long IPCC (Intergovernmental Panel on Climate paddock.qld.gov.au/queenslanddroughtmonitor/ Change) (2000) IPCC Special Report Emissions queenslanddroughtreport/. Scenarios: summary for policy makers. Accessed DAFF (2015) Drought Declared Areas in Queensland. at https://www.ipcc.ch/pdf/special-reports/spm/ Queensland State Government. Accessed at https:// sres-en.pdf. www.longpaddock.qld.gov.au/queenslanddrought IPCC (2012) Field C, Barros V, Stocker T, Qin monitor/queenslanddroughtreport/index.php. D, Dokken D, Ebi K, Mastrandrea M, Mach K, Delworth TL and Zeng F (2014) Regional rainfall Plattner G, Allen S, Tignor M and Midgley P decline in Australia attributed to anthropogenic (2012) Managing the Risks of Extreme Events and greenhouse gases and ozone levels. Nature Disasters to Advance Climate Change Adaptation. Geoscience. Accessed at http://www.nature.com/ In: A Special Report of Working Groups I and II of ngeo/journal/vaop/ncurrent/full/ngeo2201.html. the Intergovernmental Panel on Climate Change. Cambridge UK and New York NY USA. Department of Foreign Affairs and Trade (DFAT) (2014) Australia’s Environment at a Glance. IPCC (2013) Summary for Policymakers. In: Australia Government. Accessed at Climate Change 2013: The Physical Science Basis. http://www.dfat.gov.au/facts/env_glance.html. Contribution of Working Group I to the Fifth Assessment Report of the Intergovernmental Panel DPI (Department of Primary Industries NSW) (2014) on Climate Change [Stocker TF, Qin D, Plattner NSW Seasonal Conditions Report: September 2014. G-K, Tignor M, Allen SK, Boschung J, Nauels A, Xia NSW State Government. Accessed at http://www. Y, Bex V and Midgley PM (eds.)]. dpi.nsw.gov.au/__data/assets/pdf_file/0009/529380/ nsw-seasonal-conditions-report-sept-2014.pdf. IPCC (2014) Impacts, Adaptation, and Vulnerability. Contribution of Working Group II to the Fifth DPI (2015) NSW Seasonal Conditions Report: Assessment Report of the Intergovernmental February 2015. NSW State Government. Accessed at Panel on Climate change [Field C, Barros V, http://www.dpi.nsw.gov.au/agriculture/emergency/ Mach K and Mastrandrea M (eds)]. Cambridge seasonal-conditions/regional-seasonal-conditions- University Press, Cambridge, United Kingdom reports/seasonal-conditions/feb-2015. and New York, NY USA.

Page 20 CLIMATECOUNCIL.ORG.AU Klamt M, Thompson R and Davis J (2011) Early Timbal B, Arblaster J, Braganza K, Fernandez E, response of the platypus to climate warming. Global Hendon H, Murphy B, Raupach M, Rakich C, Smith Change Biology. 17(10): 3011-3018. I, Whan K and Wheeler M (2010). Understanding the Anthropogenic Nature of the Observed Rainfall LeBlanc M, Tweed S, Van Dijk A and Timbal B Decline Across South-Eastern Australia. The Centre (2012) A review of historic and future hydrological for Australian Weather and Climate Research. changes in the Murray Darling Basin. Global Accessed at http://www.cawcr.gov.au/publications/ Planetary Change (80–81): 226–246. technicalreports/CTR_026.pdf. MacNally R, Horrocks G, Lada H, Lake PS, Thomson Timbal B and Drosdowsky W (2012). The relationship JR and Taylor AC. (2009) Distribution of anuran between the decline of south eastern Australia amphibians in massively altered landscapes in rainfall and the strengthening of the sub tropical southeastern Australia: effects of climate change ridge. International Journal of Climatology 33(4): in an aridifying region. Global Ecology and 1021–1034. Biogeography. 18(5): 575-585. TRA (Tourism Research Australia) (2010) Impact of Melbourne Water (2013) Annual Report 2012–13. the Drought on Tourism in the Murray River Region: Accessed at http://www.melbournewater.com.au/ Summary of Results. Tourism Research Australia aboutus/reportsandpublications/Annual-Report/ (TRA), Department of Resources, Energy and Documents/2013_Annual_Report.pdf. Tourism, Canberra, ACT, Australia, 3 pp. Melbourne Water (2014) Melbourne Water Use. Urban Water Security Research Alliance (UWSRA) The Victorian Government. Accessed at http:// (2011) Impact of Climate Change on Urban www.melbournewater.com.au/waterdata/wateruse/ Water Security in SEQ. Accessed at http://www. Pages/default.aspx. urbanwateralliance.org.au/publications/factsheets/ Murphy B and Timbal B (2008) A review of UWSRA_Fact_Sheet_2.pdf. recent climate variability and climate change in van Dijk AIJM, Beck HE, Crosbie RS, de Jeu RAM, southeastern Australia. International Journal of Liu YY, Podger GM, Timbal B and Viney NR (2013) Climatology 28(7): 859–879. The Millennium Drought in southeast Australia NSW Office of Water (2010) Climate Change and its (2001–2009): Natural and human causes and Impacts on Water Supply and Demand in Sydney. implications for water resources, ecosystems, The Department of Environment, Climate Change economy, and society. Water Resources Research and Water. Accessed at http://www.metrowater.nsw. 49:1040–1057. gov.au/sites/default/files/publication-documents/ WC (Water Corporation (Western Australia)) (2012). climatechange_impact_watersupply_summary.pdf. Yearly stream flow for major surface water sources. Perkins S and Alexander L (2013) On the Accessed at http://www.watercorporation.com. measurement of heatwaves. Journal of Climate. 26: au/d/dams_streamflow.cfm. 4500-4517. Western Australia Department of Water (2009) Queensland Water Commission (2010) South Climate change, water demand and water East Queensland Water Strategy. Queensland availability scenarios to 2030. Government of Government. Accessed at http://www.dews.qld.gov. Western Australia. Accessed at http://www.water. au/__data/assets/pdf_file/0019/32734/seqws.pdf. wa.gov.au/PublicationStore/first/88706.pdf. Reisinger A, Kitching RL, Chiew F, Hughes L, Western Australia Water Corporation (2014) What Newton PCD, Schuster SS, Tait A and Whetton is the Integrated Water Supply Scheme. Accessed P (2014) Australasia. In: Climate Change 2014: at http://www.watercorporation.com.au/home/ Impacts, Adaptation, and Vulnerability. Part faqs/water-supply-and-services/what-is-the- B: Regional Aspects. Contribution of Working integrated-water-supply-scheme Group II to the Fifth Assessment Report of the Wittwer G and Griffith M (2011) Modelling drought Intergovernmental Panel on Climate Change and recovery in the southern Murray-Darling basin. [Barros VR, Field CB, Dokken DJ, Mastrandrea MD, Australian Journal of Agricultural and Resource Mach KJ, Bilir TE, Chatterjee M, Ebi KL, Estrada Economics, 55(3): 342-359. YO, Genova RC, Girma B, Kissel ES, Levy AN, MacCracken S, Mastrandrea PR and White LL (eds.)] World Bank (2013) Urban Population (% of total). Cambridge University Press, Cambridge, United Accessed at http://data.worldbank.org/indicator/ Kingdom and New York, NY, USA, pp. 1371-1438. SP.URB.TOTL.IN.ZS. The Guardian (2014). Southern Australia faces World Bank (2015) GDP growth (annual %). Accessed water crisis by end of century due to climate at http://data.worldbank.org/indicator/NY.GDP. change. 14 July 2014. Oliver Millman. Accessed at MKTP.KD.ZG?page=1. http://www.theguardian.com/science/2014/jul/14/ World Meteorological Organization (WMO) (2014) southern-australia-faces-water-crisis-by-end- Atlas of Mortality and Economic Losses from of-century-due-to-climate-change. Weather, Climate and Water Extremes (1970–2012). World Meteorological Organisation no. 1123. Accessed at http://www.wmo.int/pages/prog/drr/ transfer/2014.06.12-WMO1123_Atlas_120614.pdf.

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Cover image: “It can break innumerable times” by Flickr user Lotus Carroll licensed under CC by -NC-SA 2.0 Page 4: Figure 1 “Cows in drought stricken fields, Wagga Wagga NSW” by Flickr user John Shilling licensed under CC by –NC-ND 2.0 Page 5: Figure 2 “Dead trees, South Australia” by Flickr user Gary Sauer- Thompson licensed under CC by –NC 2.0 Page 7: Figure 3 “Recycling water in Melbourne” by Flickr user Louisa Billeter licensed under CC by –NC-SA 2.0 Page 8: Figure 4 “Lake Hume during drought in 2007, Victoria” by Flickr user Tim J Keegan licensed under CC by –SA 2.0 Page 13: Figure 8 “Dry paddocks near Junee, NSW” by Flickr user Tim J Keegan licensed under CC by –SA 2.0 Page 14: Figure 9 “A sheep grazes in dry pasture” by Flickr user Jo Morcom licensed under CC by –NC-SA 2.0.