Chapter 2
The impacts of climate change for the Australian agricultural sector
Introduction
2.1
The committee received many submissions and substantial evidence on the
implications of climate change for the Australian agricultural sector. The
potential impacts of climate change are diverse. Some impacts are direct, such
as climatic changes to agricultural land, and others are indirect, such as the
implications of government policy related to climate change.
2.2
This chapter begins with an overview of the Australian agricultural
sector. The chapter then provides a brief discussion on the limitations of
predicting the impacts of climate change. The chapter then discusses the implications
for the Australian agricultural sector of specific climatic impacts of climate
change. The discussion then moves to some of the broader implications of
climate change, such as the impact on rural communities, the impact on
biodiversity and how consumer expectations in relation to climate change issues
will impact on the agricultural sector.
2.3
The opportunities and challenges that climate change impacts have on
current and future farm enterprises are discussed in detail in Chapter 3 of the
report. The committee received a substantial number of submissions and evidence
outlining the impacts of an emissions trading scheme on the Australian
agricultural and forestry sector. The committee considers these issues in
detail in Chapter 4 of the report.
The Australian agricultural sector
Composition of the sector
2.4
The National Farmers' Federation (NFF) provided the following summary of
the Australian agricultural sector's contribution to the Australian economy:
The agricultural sector, at farm-gate, contributes approximately
3% of Australia's total Gross Domestic Product (GDP). However, when factoring
in the value-adding activities that occur to farm outputs post farm-gate, and
the value of all the economic activities supporting farm production in the
farm-input sector, agriculture has averaged a contribution of 12.1% of GDP
(approximately $103 billion in 2004-05 dollar terms) in the six years ending
2003-04. Australian agricultural exports are valued at approximately $30
billion annually, accounting for around one fifth of Australian merchandise
exports.
In addition, there are currently 308,000 people directly employed
in Australian agriculture. However, the complete agricultural supply chain,
including affiliated industries, provides over 1.6 million jobs to the
Australian economy (1-in-6 of all jobs).[1]
2.5
The Australian Bureau of Statistics summarised the main industries
comprising the agricultural sector for the period 2006-07 as follows:
... the number of agricultural businesses at 30 June 2007 had fallen by 3% to 150,403 [since 1 July 2006].
The beef cattle farming industry was the largest, with around 30%
of all agricultural businesses. The mixed farming sector (grain-sheep/beef
cattle) was the next largest with around 9%, followed by sheep farming with 8%.[2]
2.6
In terms of the gross dollar value, the NFF's website states that the
top three agricultural commodities produced nationally are: cattle and calves;
milk; and wheat.[3]
Vulnerability of the Australian
agricultural sector to climate change
2.7
A number of submissions highlighted the vulnerability of the Australian
agricultural sector to climate change. For example, Mr Ian Bowie's submission
cited work by the Australian Bureau of Agricultural and Resource Economics
which indicated that while agricultural production would decline globally, some
of Australia's major competitors may not be as challenged by this as Australia.[4]
Similarly, the submission of Meat and Livestock Australia highlighted the
vulnerability of the Australian agricultural sector to climate change:
Projections indicate that relative to other developed countries,
Australia is exceptionally sensitive to climate change and agriculture is one
of the most vulnerable sectors due to the impacts on productivity of changes in
water availability, water quality, temperature, and pests and diseases.[5]
2.8
The committee also notes the assessment of the Garnaut Climate Change
Review of the vulnerability of various subsectors of the agricultural sector to
climate change, particularly the irrigated sheep, dairy and cattle industries
with a very high vulnerability to climate change.[6]
The limitations of predicting the impacts of climate change
2.9
The committee's Interim Report summarises regional climate change
projections from Climate Change in Australia, a joint project of the Commonwealth
Scientific and Industrial Research Organisation (CSIRO) and the Bureau of
Meteorology (BoM).[7]
The committee noted in its Interim Report that there is some uncertainty in making
climate projections, and that there is ongoing work to produce long-term
climate projections on a global and national scale. The committee also noted
the need for further work to be done to downscale climate change projections to
a local level to be of greater use to farmers in decision-making.[8]
2.10
The CSIRO made the following qualification in its submission about how
this uncertainty in projections impacts on the reliability of predicting the
impacts of climate change:
While there are some general principles about how impacts of
climate change will vary geographically, regional indications of climate change
impacts are highly uncertain ... regional climate change projections are
currently more useful for describing the wide range of uncertainty and for
probabilistic risk assessment than serving as reliable predictors for planning
and decision making.
The comments [in the CSIRO's submission] should therefore be
used as an indication of the likely range of impacts for which primary
industries will have to prepare, and NOT as a reliable predictions of exactly
where specific impacts will occur.[9]
2.11
In its Interim Report the committee acknowledged the frustration that
this type of uncertainty can cause for those in the agricultural sector.[10]
However, with these limitations of current climate projections in mind, the
committee is of the view that the information available on future climate is sufficient,
in any case, to provide the foundation for discussion about the potential implications
of climate change on the Australian agricultural sector.
Climatic impacts of climate change
2.12
The CSIRO's submission provided an extensive description of the likely
range of impacts of climate change, by region and by agricultural industry.[11]
The Queensland Government and the Victorian Department of Primary Industries
also provided the committee with detailed information on the impacts of climate
change on the specific agricultural industries in those states.[12]
Industry organisations also made submissions to the committee setting out the
potential impacts of climate change on their specific industry.[13]
2.13
This section of the report discusses some of the common biophysical
impacts that were raised in submissions and evidence:
-
competition for water resources and reduced water availability;
-
increases in temperature;
-
increasing frequency of extreme climatic events;
-
elevated levels of carbon dioxide in the atmosphere; and
-
pest and disease distribution and pathogenicity, and weed
distribution and management.
2.14
Although issues are discussed individually, it is important to recognise
that there is extensive interplay between impacts.
Water resources
2.15
One of the well-recognised implications of climate change on the agricultural
industry, particularly in southern Australia, is reduced water availability in
a hotter, drier climate.[14]
This was highlighted in the Intergovernmental Panel on Climate Change Fourth
Assessment Report:
As a result of reduced precipitation and increased evaporation,
water security problems are projected to intensify by 2030 in southern and
eastern Australia and, in New Zealand, in Northland and some eastern regions...[15]
2.16
As the CSIRO noted in its submission, there are multiple factors which interact
to threaten water resources: significant development of surface and groundwater
resources; declining rainfall in recent decades; and projected reductions in
future rainfall and runoff.[16]
2.17
The New South Wales Irrigators' Council submission clearly sets out the
implication of reduced water availability - competition for water resources
amongst all users:
We have recognised that there are multiple users of water –
human needs, stock needs, the environment and irrigated agriculture.
We have recognised that those users must share the available
water resources – and that some needs are more critical than others.
We have recognised that water must be distributed based on
sustainable yields over the longer term.[17]
Implications of reduced water
availability
2.18
Reduced water availability affects all areas of the agricultural sector,
and many submissions emphasised this point. The NSW Irrigators' Council noted:
Irrigation sits at the very forefront of climate change policy.
The availability and reliability of water is clearly at the heart of
irrigation. It is also at the heart of climate change.[18]
2.19
The Western Australian Department of Water highlighted the importance of
reliable on-farm water supplies in the dryland agricultural areas of Western
Australia:
... seasonal fluctuations in rainfall necessitate the design of
reliable on-farm water supplies so that farming enterprises can continue to
function in years with low rainfall. When failure occurs, carting water
generates high costs to the farmer in terms of both dollars and time.[19]
2.20
Apple and Pear Australia Limited (APAL) outlined the value of water for its
industry:
In a hotter, potentially drier climate, evaporation and
transpiration will be increased leading to increased demands for irrigation and
increased water use per hectare. Water has become a valuable resource and is
often not available when required. This increased requirement for water, if
water is expensive or not available, would lead to reduced orchard viability.[20]
2.21
The CSIRO in its coverage of the impacts of climate change on the
Australian agriculture sector, highlighted a number of industries as vulnerable
to reduced rainfall and water availability. For the sugarcane industry the
projected change in the amount, frequency and intensity of future rainfall will
be '[p]robably the greatest impact (and adaptation challenge)':
In many regions the amount of effective rainfall available to
the crop will be reduced, whilst water demand is likely to increase due to
greater rates of evapotranspiration linked to atmospheric warming.[21]
2.22
In relation to viticulture, the CSIRO said the 'water demand of
winegrape vines will increase in a warmer climate while rainfall and, more
importantly, runoff to water storages is projected to decrease'.[22]
The CSIRO also highlighted the vulnerability of cropping in current 'dry
margins', but did note that there may be an expansion into areas that are
currently too wet for regular cropping.[23]
The CSIRO also indicated that the irrigated dairy industry would be impacted by
reduced water availability and concluded that there should be an assessment of the
vulnerability of irrigated dairy to reduced water supply.[24]
The relationship between rainfall
and run-off
2.23
The committee's Interim Report highlighted the disparity in rainfall
projections by different climate models and the difficulty this creates in
making definitive statements about changes in precipitation.[25]
Dr Mark Howden of the CSIRO noted that for southern Australia there is 'a
fair bit of congruence in terms of predictions of lower rainfall', however there
still remains uncertainty as to whether there will be a large or small amount
of reduction.[26]
2.24
In addition to the uncertainty of predicting changes in rainfall is the further
complexity in determining how reduced rainfall will impact on run-off. eWater Cooperative
Research Centre (eWater CRC) explained the nature of the relationship in its
submission:
A decrease in catchment precipitation of 10% may lead to a
decrease in catchment runoff in the order of 20% to 30%, due to complicated
non-linear relationships between the factors.[27]
2.25
Dr Michael Coughlan of the Bureau of Meteorology explained to the
committee the difficulties in accurately measuring reductions in run-off:
...measuring rainfall is a lot simpler than measuring run-off. In measuring
rainfall we put a bucket out there and measure how much rain falls into it.
What happens to the rain after it falls is a pretty complex process. You cannot
– or it is difficult – to measure it directly, except what then ultimately ends
up in the rivers. So that generally has to be done through some modelling
process and if that modelling process is 'uncertain'...often what we ultimately
observe will differ from what we actually model. Getting the modelling right is
a difficult process. It often depends very much on the particular catchment for
which you are doing your modelling. So what you might observe as effective
run-off in, say, Western Australia might differ quite markedly from, say, in
south-eastern Australia.[28]
2.26
Professor Michael Young of the Wentworth Group of Concerned Scientists, acknowledged
that there was much more 'sophisticated' science behind such predictions, but provided
the committee with a 'rule of thumb' estimation for reduction of run-off
resulting from a reduction in rainfall:
The reality is...that for every one per cent reduction in mean
rainfall, inflows into dams dropped by about three per cent. As you get to
really dry steps, it becomes more like four per cent and even five per cent. That
really matters and it happens because you have to wet a landscape before you
get run-off.[29]
2.27
The evidence of a representative of the Murray-Darling Basin Commission,
in describing the impact of successive dry seasons on run-off in the Murray-Darling
Basin, provided a prime example of the phenomena described by Professor Young:
What we have at the moment with the current situation is the 10 lowest
rainfall years on record, and so average inflows into the Murray system have
dropped dramatically. The year 2006-07 was the driest on record. But perhaps
more importantly there has never been a period of regularly dry seasons one
after the other...
The pattern we have been seeing is that rainfall has been
reduced during the autumn. The effect of this is that the catchments do not wet
up in the same way as they did previously and so there is a much greater
decline in run-off than in rainfall.[30]
2.28
The committee also questioned representatives of the Murray-Darling
Basin Commission on how reduced inflows into the Murray-Darling Basin would
impact on the water available for irrigation and the environment:
There was work done by the Victorian Department of
Sustainability and Environment as part of the northern region water strategy...that
looks at the reduction of inflows under a range of scenarios and then how that
would play out in terms of reductions to irrigation and to environmental flows...For
example, for the Murray, under the medium impact of climate change scenario,
they have modelled a 25 per cent reduction in inflows, a six per cent reduction
to irrigation and a 33 per cent reduction to the environment. So that is
assuming that, if you like, the rules are not changed and you will get that
disproportionate impact for the environmental water.[31]
2.29
The representative for the Murray-Darling Basin Commission agreed that
such a disproportionate impact would not be sustainable.[32]
Sustainable Water Policies
2.30
The Gwydir Valley Irrigators Association stated in its submission that
one of the challenges of government is to decide how to share what may be
decreased, or increased, levels of water availability.[33]
2.31
The committee received submissions giving examples of water policies
which enabled sustainable water distribution to agriculture. The Western
Australian Department of Water noted that 'a well planned, well organised and
integrated' approach to water supply development was required in the dryland
areas of the agricultural regions of Western Australia:
The Rural Water Plan was developed as a strategic tool to
encourage rural farming communities to be involved in water supply projects;
accept an element of responsibility; take ownership of local water supply
assets; and engage in an ongoing planning and improvement process. By employing
an integrated planning approach, it is possible to develop reliable on-farm
water supplies that meet all domestic, crop spraying and livestock needs in
most agricultural areas. An ad hoc approach to water supply development
can result in inadequate or ineffective supplies that fail during extended dry
periods which are predicted to be the norm in the future.[34]
2.32
Both the NSW Irrigators' Council and the Gwydir Valley Irrigators
Association made submissions to the effect that the current water sharing plans
in NSW are robust enough to deal with climate variability and climate change.
In its submission the NSW Irrigators' Council described how, in NSW, Water
Sharing Plans (WSPs) have been documented and agreed which recognise the
multiple demands on water resources:
An Available Water Determination (AWD) pursuant to the WSP is
made on a regular basis stating the total amount of water that can be used in a
delineated time period by all users. In the event that climate variability or
change result in less water being available, the AWD method set out in the WSP
will distribute that water which is available in a pre-determined method.[35]
2.33
However, the Murray-Darling Basin Commission noted in their evidence
that current systems for water distribution only cover part of the extraction
cycle:
What we are really seeing is – under scarcity of water – that
there is increasing demand. There are a whole lot of ways of accessing that
available water resource, and the systems we have for allocating water have
only developed to deal with part of the extraction cycle.[36]
Higher temperatures
2.34
Higher temperatures are projected to have significant impacts on the
Australian agriculture sector. Dr Mark Howden of the CSIRO noted in his
evidence to the committee that there is a 'strong degree of congruence in the
forecasts about increases in temperature' and these can be slated back to
regional implications.[37]
2.35
The CSIRO's submission stated that there is an increased likelihood that
heat stress on livestock and crops is likely to occur in certain areas of
Australia, for example the 'Mediterranean' south-west of Western Australia, the
south-east of South Australia, and the south-west of Victoria; and the
'subtropical moist' areas of the south-east coast.[38]
The Queensland Government also stated in its submission that heat stress would
constrain beef production and that heat shock will decrease the dough making
qualities of grain.[39]
2.36
The CSIRO noted the intensive livestock industry in south-west Tasmania
may benefit from 'warming and drying' and there may be reduced energy demands
for heating production sheds.[40]
2.37
Growcom provided the committee with details of a grower workshop on
horticulture and climate change it hosted in January 2008. Participants at the
workshop indicated that increased temperatures were an important issue for
consideration in the horticultural industry:
increased temperature is likely to present a more critical issue
than reduced rainfall due to the sensitivity of crops to temperature change and
the intensive / irrigated nature of horticulture production.[41]
2.38
APAL outlined in its submission that increasing temperatures will be an
important factor for the pome fruit industry:
The most obvious impact for pome fruit such as apples and pears
will be the expected continued rise in temperatures and hence a reduction in
chilling hours.
...Another impact of warming, particularly rising minimum
temperatures, is expected to be a decreased incidence of frost. As apples
require frost-free conditions once the buds begin to open there may be some
benefits in this. However, the situation is likely to be more complex. For
example, if rising minimums are accompanied by greater variability there may be
an increased risk of unexpected frost at critical times.[42]
2.39
Evidence to the committee also demonstrated the important interplay
between higher temperatures and reduced water availability:
...just a one per cent increase in average temperature is deemed
to have a significant impact, because it means that the longer, warmer period
of active plant growth – those forested catchments – will use more water and,
therefore, less will go as run-off.[43]
2.40
Increasing temperatures are also expected to have impacts on pest and
disease distributions across Australia, and this is discussed below in the
section 'Pests, disease and weeds'.
Extreme climatic events
2.41
The committee's Interim Report briefly discussed Climate Change in Australia's
projections in relation to extreme climatic events such as droughts,
bushfires and storms. Climate Change in Australia projected
that there would be:
-
increases in agricultural droughts (periods of extremely low soil
moisture);
-
a substantial increase in fire weather risk in south-eastern Australia;
and
-
the potential for significant increases in inundations from storm
surges, resulting in flooding and erosion, due to higher mean sea level and
more intense weather systems.[44]
2.42
The Intergovernmental Panel on Climate Change also highlighted the
effect of drought and fire on agricultural and forestry production in Australia:
By 2030, production from agriculture and forestry is projected to
decline over much of southern and eastern Australia, and over parts of eastern New
Zealand, due to increased drought and fire.[45]
2.43
The committee received some submissions and evidence on the impact that
these extreme climatic events would have on the Australian agricultural sector.
The Victorian Department of Primary Industries stated in its submission that
these increases in extreme climatic events were a greater threat to agriculture
and forestry than anticipated changes in temperature:
Increased climate variability, which implies an increased
frequency and intensity of extreme climatic events, is likely to pose a greater
threat to many agriculture and forestry businesses than anticipated changes in
average temperatures. This is due to its combination of greater
unpredictability coupled with increased intensity of natural disasters e.g.
fire, flood, drought and disease. An important issue for farmers is their
capacity to recover from extreme climate-related events such as droughts,
floods and fires.[46]
2.44
Similarly, the BoM stated that the impact of climate change on
agriculture will result in the interaction of climate variability and long-term
trends, leading in particular to more frequent extreme events:
Such outcomes might be characterised by
events such as the recent droughts, which have seen record high temperatures
compounding the rainfall deficiencies.
This interaction means that climate change is likely to occur as
a series of shocks during which systems experience new combinations of
stressors.[47]
2.45
The evidence to the committee on the impacts of drought demonstrated
that the impacts went beyond reduced precipitation and water availability. Ms Nicolette
Boele of the Agricultural Alliance on Climate Change (AACC) described the
ongoing pressure of droughts as a 'cancer', which will only be exacerbated by
climate change.[48]
The Queensland Government's submission noted that more frequent and severe
drought events would mean that the state's stock route network, which is used
for moving stock and short term drought relief, would become increasingly
important to the pastoral industry.[49]
The CSIRO also noted that the cost of horticultural crops tend to rise during
droughts, and that this would be expected to occur more often if there was an
increased frequency of droughts.[50]
2.46
A number of submissions highlighted the potential risks faced by the
forestry industry from a projected increase in frequency and severity of
bushfires.[51]
Rising carbon dioxide (CO2)
levels
2.47
Another of the biophysical changes that may have an effect on
agricultural production is the increasing concentration of carbon dioxide in
the atmosphere. As the eWater CRC explained in its submission:
The effect of rising atmospheric CO2
concentrations on vegetation growth in agricultural zones, generally, is to
increase vegetation productivity for a given amount of available water (i.e.
precipitation). This 'CO2-fertilisation' effect will go some way to
counteracting decreases in productivity if precipitation decreases over time.[52]
2.48
The eWater CRC submission goes on to state that there is some evidence
already that there have been increases in vegetation cover over the past 2-3
decades, even in places where precipitation has declined. However, the eWater
CRC cautions:
There are no simple, generic rules about how vegetation will
change. There is some evidence indicating that enhanced CO2 concentration
will increase the productivity of long-lived, deep-rooted species (e.g.,
perennial vegetation) more than short-lived species (e.g., annual grasses and
crops).[53]
2.49
According to the eWater CRC, the implications of this are that
tree-based cropping systems may become relatively more productive than those
systems are currently.[54]
On this point, the CSIRO note that grazing in some regions of Australia may be
impacted by rising carbon dioxide levels favouring trees over pasture
production, and that pasture quality may decline.[55]
2.50
The Queensland Government submission also noted that a rise in carbon
dioxide concentration in the atmosphere may increase pasture growth,
particularly in water-limited environments. However, the Queensland Government
referred to studies which indicated that this increase in plant productivity
may be offset by a 10% reduction in rainfall:
A rise in CO2 concentration is likely to increase
pasture growth, particularly in the water-limited environments in Australia and
specifically Queensland. However, if rainfall is reduced by 10%, this CO2
benefit is likely to be offset. A 20% reduction in rainfall is likely to reduce
pasture productivity by an average of 15% and live weight gain in cattle by
12%, substantially increasing variability in stocking rates and reducing farm
income.[56]
2.51
The Queensland Government submission also outlined the impact of increased
levels of carbon dioxide in the atmosphere on the nitrogen content of plants:
Elevated concentrations of CO2 significantly decrease
leaf nitrogen content and increase non-structural carbohydrate, but cause
little changes in digestibility. In farming systems with high nitrogen forage
(e.g., temperate pastures), these effects are likely to increase energy
availability, nitrogen processing in the rumen and productivity. In contrast,
where nitrogen is deficient (e.g., Queensland's extensive rangelands), higher
temperatures are likely to exacerbate existing problems by decreasing
non-structural carbohydrate concentrations and digestibility, particularly in
tropical C4 grasses.[57]
2.52
eWater CRC also noted that with increasing levels of carbon dioxide, and
the possibility of increased productivity to some types of vegetation, woody
weed control may become increasingly important.[58]
The CRC for National Plant Biosecurity stated that elevated carbon dioxide
levels in the atmosphere may also affect plant pest pathogens.[59]
The issue of weed management and pests is discussed further in the section 'Pests,
disease and weeds'.
2.53
A number of submissions highlighted the impact changing climate could
have on the distribution and pathogenicity of pests and diseases, and weed distribution
and management. These impacts are generally secondary impacts, resulting from
changes in temperature, rainfall or atmospheric carbon levels.[60]
Distribution and pathogenicity of pests
and diseases
2.54
The CRC for National Plant Biosecurity stated in its submission that
changes are already occurring in the distribution of pests and pathogens:
A poleward shift in the geographical range of some pests and
pathogens has been observed during the last century ... Rising temperatures
associated with climate change are predicted to be associated with the future
poleward movement of other Emergency Plant Pests (EPPs) ...[61]
2.55
The CRC for National Plant Biosecurity used the example of citrus canker
to demonstrate how these changes could impact the Australian agricultural
sector:
A recent modelling analysis indicated that if citrus canker had
become established in Queensland, the geographical range of the pathogen, Xanthomonas
axonopodis pv.citri, was predicted to extend further south to major
Australian citrus growing regions with a 1-5ºC temperature increase ...[62]
2.56
APAL indicated that increased pesticide applications, one of the
potential flow on effects of changed plant pest distributions, could impact on
the export market for orchard fruits:
Warmer conditions will have significant effects on the orchard
ecosystem including many orchard pests and potentially their predators. There
will be movement of warm climate pests, notably fruit flies, from warmer
production areas to areas that are currently free of these pests. This would
necessitate additional pesticide applications targeting this pest and
potentially affects market access for fruit to export countries such as Japan.
For other pests such as codling moth and light brown apple moth,
it is anticipated there would be an increase in the number of breeding cycles
per year ... As the number of insects in an orchard increases with each breeding
cycle an extra cycle will lead to a substantial increase in insect pressure.
This has a compounding effect in that the extra cycle also leads to an increase
in the number of insects that over winter and hence to an increase in the number
of insects present in the first breeding cycle in the following spring. As many
of the chemicals used to control these pests are banned in export countries, as
are the presence of live insects in consignments, this would have a negative
impact on the export of fruit out of Australia.[63]
2.57
APAL also stated that warmer weather would also increase the incidence
of plant diseases:
...plant diseases grow, multiply and infect at faster rates in
warmer weather. Hence with global warming there would be an increase in the
incidence, severity and spread of orchard diseases that will need to be
controlled. This would have a very negative impact on the growing organic
industry, which lacks good disease control chemicals. In addition, as for
insecticides, many of the chemicals used to control these diseases are banned
in export countries, as are the presence of the diseases in consignments.[64]
2.58
The Queensland Government, while highlighting the many ways climate
change could impact on the distribution of pests, also noted that there may be
some benefits of climate change in terms of controlling some pests:
Climate change will reduce the impacts and/or range of some pest
species and there is likely to be increased opportunities to better manage some
species due to less favourable climatic conditions (e.g. reduced rainfall,
drought).[65]
2.59
While predictions can be made about the changing distribution of plant
pests, the CRC for National Plant Biosecurity expressed the concern that other
impacts of plant pests required further investigation:
While future spatial distribution can be predicted under climate
change scenarios using models and examining historical trends, there appears to
be limited knowledge of how climate change will impact on the biology of the
EPPs (e.g. pathogenicity) and how the interaction with their host responds to
potentially many climatic factors. Major climate change factors identified that
affect plant pest infestation and diseases include increased atmospheric CO2,
frost, heavy and unseasonal rains, increased humidity, drought, cyclones and
hurricanes, and warmer temperatures.[66]
2.60
Of particular concern is the impact of increased levels of carbon
dioxide in the atmosphere which, according to the CRC for National Plant
Biosecurity, may modify pathogen aggressiveness and/or host susceptibility and
affect the initial establishment of the pathogen.[67]
2.61
The Queensland Government submission also addressed the impact of
climate change on the distribution and pathogenicity of animal diseases:
The world is facing an unprecedented impact from emerging and
re-emerging animal diseases that have a major impact on production and trade
(e.g. nipah virus, foot and mouth disease, tuberculosis). Climate change can
affect many processes that influence animal diseases including the pathogen or
parasite, the host, the vector and the behaviour of the disease (epidemiology).
Warmer temperatures and more extreme rainfall events will produce conditions
that are more favourable to many livestock diseases. Insect vectors of disease
such as mosquitoes and midges are likely to expand their range increasing the
risk of disease spread to new areas.[68]
Weed distribution and management
2.62
The committee received a limited number of submissions that highlighted
the importance of weed distribution and management as one the impacts arising
from climate change.
2.63
In its submission, the CRC for Australian Weed Management summarised the
potential that climate change presented for weed invasion:
Overall, climatic changes place existing vegetation, whether
native, pasture or crops, under stress. This creates spaces for new species to
move into, and species with efficient dispersal mechanisms, whether by bird,
wind, water or by human activities, are the best equipped to take advantage of
the spaces created. Invasive plants generally have excellent seed transport
mechanisms, often by human activity or by birds, and are likely to spread
rapidly into new areas, quickly exploiting changing climatic conditions that
favour their establishment. Climate change can therefore be expected to favour
invasive plants over established vegetation including crops, especially if
accompanied by an increase in extreme conditions such as droughts alternating
with very wet years.[69]
2.64
The CRC for Australian Weed Management outlined in its submission how
specific changes in climate may impact weed distribution, for example: as a
result of higher temperatures all invasive plants can be expected to shift
southward in range, with tropical and subtropical species moving south, and
temperate species being displaced southward; many weeds have a carbon
metabolism which will benefit greatly from increased atmospheric carbon
dioxide; reduced rainfall may limit or reduce the distribution of weeks in some
localities. However, the CRC for Australian Weed Management stated that there
was a 'real need for an independent scientific review of currently-available
modelling tools used to predict how plants, in particular current and potential
weedy species, will respond to changing climate scenarios'.[70]
2.65
In evidence to the committee, Associate Professor Christopher Preston of
the CRC for Australian Weed Management stated that, in his opinion, the biggest
issue for weed distribution in the context of climate change is the reduced
availability of water:
One of the issues that arise is the inability to have good
pasture coverage because of lower rainfall patterns at various times, and that
allows weed invasion into pastures. The second one that is quite important in
the grains industry has been the change in rainfall pattern from one almost
entirely dominated by winter rainfall to having increasing amounts of summer
rainfall. Farmers are needing to spend more time, effort and money controlling
summer weeds because they need that moisture to grow a crop. Severe weather
conditions can also be a major issue because they create gaps in the
environment for weeds to invade.[71]
2.66
Associate Professor Preston also identified the abandoning of farms,
arising from reduced water availability, as another potential means of weed
invasion:
The majority of farmers in Australia have most of their equity
in land and their land is only as valuable as the water that they can get. So
with declining water resources, whether that is declining irrigation or declining
rainfall, there is the chance that for many of these farmers their land will
become less and less valuable. That makes it more and more difficult for them
to move out of the industry or move into different industries and it creates
the issue where, instead of changing industries, the land is just abandoned and
allowed to go to waste. Again, that is an opportunity for weed invasion.[72]
2.67
The CRC for Australian Weed Management also indicated that there is a
need to modify existing weed risk assessment systems to take into account
possible 'sleeper' weeds that may be favoured by a changing climate.[73]
2.68
In evidence to the committee, Associate Professor Preston raised a
further issue in relation to weed management, specifically the introduction of
species for biofuel production:
The Australian environment is littered with examples of
industries which seemed like a good idea at the time but which, for one reason
or another, never really made it. In many of those situations we have plant
species that have become weeds and animal species that have become feral. Rubber
vine is probably a good example of this; olives are another example that I am
very familiar with, coming from South Australia – these sorts of boom and bust
industries. I think we need to be very careful about how we go forward with the
biofuels sector. Many of the species that have been touted as prominent
biofuels species, like jatropha, are well known worldwide for being weedy, and
if the industries do not take off we could well be left with a legacy of weeds
on our hands.[74]
2.69
The committee followed up the issue of the management of new species
with Mr Kevin Goss of the Future Farm Industries CRC:
We have a weeds protocol that the [Future Farm Industries] CRC
has adopted and that we implement. The weeds protocol has being worked out in a
joint project with the CRC for Australian Weed Management ... We apply that to
all that we do. That, importantly, is not simply about bringing plants into the
country, which is a matter for Biosecurity Australia and [the Australian
Quarantine and Inspection Service]; that protocol extends to how we manage the
sites internally and to our ongoing observation of those sites and dealing with
any issues that arise.[75]
2.70
The committee also received a submission from the Council of Australasian
Weed Societies Inc which stated that 'weeds are widely recognised as one of
Australia's most pressing natural resource management issues' and that farmers
have recently ranked weeds as their greatest national resource management
issue. The Council of Australian Weed Societies submission also noted the
social costs that weed management impose on farmers:
These include health risks through toxins in livestock products
and allergenic pollens, loss of access and amenity in national parks and
waterways, and increased fire risks in peri-urban areas from dense thickets of
invasive grasses and shrubs. The major social impact of weeds is the
time-demanding nature of weed control – a loss of productive and recreational
time borne by many Australians.[76]
Non-climatic impacts of climate change
2.71
The range of impacts of climate change on the Australian agricultural
sector is not limited to climatic impacts. The next section of the report
discusses the potential flow-on effects from climate change on three areas to
demonstrate the breadth of climate change implications on the Australian
agricultural sector, specifically:
Rural communities
2.72
The impacts of climate change on the Australian agricultural sector will
have immediate consequences for rural communities. The Agricultural Alliance on
Climate Change (AACC) painted a bleak picture in its submission of the impact
of climate change on rural communities, particularly where farmers are
struggling to adapt to changing their farming practices to new climatic
conditions:
...as is happening still in some areas of Australia gripped in
drought, some farming families and communities will experience financial
hardship and chronic social pressures, especially mental health issues.
The recently established NSW Rural Mental Health Network identified
climatic change impacts, such as drought, as a key external driver of mental
health problems in rural Australia...the NSW Farmers' Association highlighted
that deaths from suicide of male farmers and farm workers are now double that
of any other group in the male population.[77]
2.73
The AACC submission went on:
If adapting to climate change proves too difficult in some
areas, populations will decline and the abandonment of rural towns and farming
areas could follow, with the consequent loss of local history, culture and dire
natural resource implications. The advent of weeds, pests, disease and erosion
could be considerable resulting from the exodus from certain rural and remote
areas.[78]
2.74
The Australian Landcare Council submitted that the social impacts of
climate change for these communities is largely being ignored:
Should climatic variability increase significantly, the social
impacts may be considerable, especially among rural communities, although it
should be said that not all social impacts will be negative. Studies by rural
social scientists of this topic should be encouraged and supported.[79]
2.75
The committee's inquiries on this issue found that there is little evidence
of work being done on the impacts of climate change on rural communities. Mr Andrew
Dolling of the Victorian Department of Primary Industries indicated to the
committee that the department is 'cognisant' of the social impacts of climate
change:
...we do take into consideration the social impacts of the various
climate change and policy scenarios. We do have an area which is specifically undertaking
social research related to a number of challenges that farming communities
face, of which climate change is one. There are, of course, others.[80]
2.76
Ms Boele of the AACC informed the committee that the AACC has not done
much work investigating the flow-on effects of climate change on rural
communities, however, the AACC is 'very committed' to better understanding
those impacts.[81]
Biodiversity in the Australian
landscape
2.77
The submission from Hawkesbury Harvest explained the important role that
the agricultural sector has in maintaining biodiversity in the Australian
landscape:
Agriculture has an important role in providing for biodiversity
at a landscape scale. Agricultural landscapes are where soils are produced,
nutrients recycled, water infiltrates through crops/grasslands. These
landscapes are also useful for maintaining remnant vegetation that can act as
fauna links through vegetative corridors and buffer the edge of urban
development from natural areas.[82]
2.78
Representatives of the forestry industry also gave evidence to the
committee about the important role that sector plays in maintaining
biodiversity.[83]
2.79
Given the important role that agriculture has in this area, the
committee was interested to hear about the impacts that climate change would
have on biodiversity. The committee was told by a number of organisations how
they assessed the biodiversity impacts of climate change and adaptative
options.
2.80
In evidence to the committee Dr Mark Howden of the CSIRO noted that 'one
of the three delivery themes that the Climate Adaptation Flagship focuses on is
biodiversity and ecosystem services'. Further, Dr Howden stated that 'clearly'
this issue is in the CSIRO's sights in its work on investigating adaptation by
the agriculture sector.[84]
2.81
Mr Goss of the Future Farm Industries CRC also gave evidence about how
that organisation's research aims to look at the impacts of biodiversity:
...we are selecting among native plants for potential productive
plants on farms. Some of these are known but some are very new. We have people
who have been out plant collecting and looking afresh at a whole suite of
Australian native plants and then putting them through an assessment. We have
got this down to, let's say, tens of plants that we think are worth a closer
look, and some of them are planted out already. Some are leguminous; some are
not. They are all perennial and they are selected because they are very well
adapted to what we see as the climate they are going to face in the future. You
could conclude that that is a good thing from a biodiversity viewpoint, but—and
I think this is behind your question—our job is not to assume that. Our job is,
when it is in these potential productive systems, to actually observe that and
then build some capacity to predict what the biodiversity benefits might be.[85]
2.82
The Sydney Centre for International Law outlined international
obligations that the Australian Government has under the Convention on
Biological Diversity (1992), as implemented in the Environment
Protection and Biodiversity Protection Act 1999 (Cth). The Sydney Centre
for International Law noted that such obligations may, in some cases, require Australia
to abandon farming in areas where serious harm to biodiversity results:
In such cases, it may be appropriate to return some areas
currently used for pasture to protected areas such as national parks. There may
be economic opportunities arising from increased tourism in new national park
areas. Of course it should be noted that protected areas themselves will be
subject to climate change pressures which will require responses.[86]
2.83
The committee heard evidence from Dr Christine Jones giving a very
positive example of how changes to farm management practices were improving the
biodiversity of some agricultural lands.
Birds have also started to come back onto their farms. People
have got thousands of little grass-feeding birds like cisticolas – which,
honestly, I had never heard of – on their farms. Apparently they were very
common at one time. And now that we are providing this habitat, little
ground-foraging native animals like bettongs, which are like little rat
kangaroos and live in grasslands, are coming back onto farms that at one time
were sprayed from one end to the other and had no ground cover. So we are
getting this whole biodiversity thing.[87]
Consumer expectations
2.84
The committee also received evidence on how climate change would impact
on consumer expectations. For example, the Food Industry Council of Tasmania
(FICT) highlighted the impact that climate change would have on the
agricultural sector from a marketing perspective because consumers are becoming
more discerning in their purchasing habits:
Food miles and carbon footprinting are two areas of focus for
FICT due to Tasmania's relatively high value of agricultural products and our
distance from consumer markets...
In some cases, these factors are already affecting Tasmanian
food and beverage products' access to markets both nationally and internationally.[88]
2.85
The FICT also noted a growing international movement to introduce 'carbon'
labels, showing greenhouse gas emissions created in the production,
transportation and eventual disposal of all products. The FICT noted that these
carbon labels would allow consumers to make choices about their consumption
based on the carbon footprint of the product.[89]
2.86
Mr Charles McElhone of the National Farmers Federation provided to the
committee an example of one study demonstrating how food miles may be
misrepresentative of the real impact of food production on the environment:
...there are some studies out of Lincoln University in New Zealand
which demonstrate that food from production systems in New Zealand shipped to Europe
has a lower carbon footprint than the same food produced in a UK heated
greenhouse and delivered to those same consumers. So to just look at the
transportation element within the carbon footprint is very misleading.[90]
2.87
Mr McElhone went on to state that food miles may in fact be an
opportunity for Australian agriculture:
We are saying that it is widely
acknowledged that Australian agriculture production systems are low
intensity in terms of their emissions per unit of production output and
therefore there may be an opportunity from a global marketplace perspective if
we get the science right in understanding the life cycle of agriculture
emissions in our production systems more effectively.[91]
2.88
Dr Michael Robinson of Land & Water Australia indicated that food
miles is definitely an area requiring further research:
We have received a very clear, very strong message that we need
to do full life cycle analysis on agricultural products so that we do not get
inappropriate, I guess, or the wrong answers out, and so that we do not get
perverse outcomes.[92]
2.89
Meat and Livestock Australia also highlighted the impacts of changing
consumer demands in the light of climate change:
...The increased media focus on greenhouse implications of
products, including food is creating an expectation of environmental 'ethics'
that is subject to manipulation by advocates of particular views, e.g. the
anti-meat lobby. A shift away from meat-based diets towards vegetable-based
diets will have important ramifications for the economic viability of livestock
producers and processing industries. It will also have impacts on landscape
health if more fragile lands are cropped rather than grazed, especially under
irrigation.[93]
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