2.67 New regional warming and rainfall change scenarios have recently
been provided for the IPCC by an international group of authors for
the Special Report on Emissions Scenarios (SRES). [1]
Based on recent projections with seven different coupled ocean-atmosphere
global climate models (AOGCMs), these scenarios suggest warmings over
Australia by the 2050s, relative to mid-20th century conditions, of
between 1ºC and 4oC depending on location and scenario, with most
warming in inland areas. Warmings in the 2080s are estimated to be in
a range of approximately 2ºC to 5.5oC. [2]
2.68 Corresponding rainfall change estimates are for rainfall decreases
in the 2050s and 2080s in excess of one standard deviation (i.e. tens
of per cent) compared with long term (30-year average) natural variability
over much of southern, and especially south-western Australia, possibly
as far north as southern Queensland. According to these results, only
Tasmania will receive any substantial increase in rainfall. [3]
2.69 These conclusions have been supported by a recently released study
by the Government of Western Australia, which endeavoured to examine
the impacts of climate change on that State at a finer scale than had
previously been undertaken. The Committee was told that the report:
2.70 In his submission to the inquiry, Dr Barrie Pittock stated that
the new IPCC regional warming and rainfall change scenarios suggest
a more negative rainfall outlook than was presented by the CSIRO in
its 1996 scenarios. His submission then proceeds to outline the implications
of what he describes as `the new global consensus on regional change
over Australia'. [5]
2.71 Dr Pittock cites a number of examples from the AOGCMs which illustrate
the likely consequences of the generally drier scenarios facing Australia,
including:
2.72 The issue of climate change impacts on Australian fauna and flora
was also brought to the attention of the Committee by the World Wide
Fund for Nature. The Committee was told that:
2.73 The CSIRO admitted that there was `less consistency when attempting
to describe future climate at a regional scale' and told the Committee
that their research, `as well as examining changes on temperature and
rainfall… is focusing on a limited number of issues that we regard
as key to making more reliable our projections of climate in Australia'.
These include:
2.74 CSIRO emphasised that `Australia's climate is subject to large
year-to-year variations in rainfall':
2.75 Dr Robert Watson concurred with CSIRO's assessment that the interaction
of global warming with ENSO patterns (El Nino and La Nina), was of great
importance to understanding the potential impact of climate change on
Australasia:
2.76 In regard to current knowledge of ENSO patterns, CSIRO explained
that:
Changes associated with the ENSO are still far from clear. There
is some indication from a number of climate model experiments that
global warming will lead to an `average' climate that resembles an
El Nino-like state. This suggests that regions that currently experience
droughts during El Nino years would experience these conditions more
often, and areas where rainfall increases during El Nino years would
become wetter. Year-to-year changes associated with ENSO variability
will continue under climate change, but there is little consensus
about the nature of this change. [11]
2.77 Dr Hans Schellnhuber, of the Potsdam Institute for Climate Impacts
Research, said that El Nino could be affected, but that more time was
needed for greater certainty about its impact:
There is very definitely not a clear consensus of what will happen
to El Nino in the course of global warming. There seems to be…
a slight tendency to be seen in the model that there is a trend towards
more El Nino like states, in general, in Australia… in this area
we generally will need another decade to be definite about that…
. [12]
2.78 Tropical cyclones could also increase in number and intensity:
Several global climate model experiments have shown an increase in
the maximum intensity of tropical cyclones (as measured by minimum
central pressure or maximum wind speed) under enhanced greenhouse
warming. Similar results are found in diagnostic studies, so an increase
in intensity is considered likely. The number of extreme tropical
cyclones would consequently increase. Other measures of changes in
cyclone behaviour (e.g. total cyclone numbers, formation regions and
tracks) exhibit variable results between models. [13]
2.79 CSIRO also informed the Committee that they had been commissioned
to investigate possible climate change within particular states and
territories. To do so, they `used a regional climate model `nested'
within the global climate model to produce simulations of climate change
with a spectral resolution of about 60 km':
The major finding from this work is that within a relatively small
average change, there exists the potential for significant
changes in the frequency of extreme climatic events. Figure 2.3 illustrates
this finding by showing modelled temperature changes in NSW. The left
hand side of the Figure shows the number of summer days in the north-west
of the State that exceeds a 35ºC maximum. The right hand side
of the Figure shows a decline in the number of nights where the temperature
falls below 0ºC. By the year 2050, hot days occur 20% more often,
and frosty nights occur 40% less often, but the average temperature
has risen by only 1.7ºC. Note the significant inter-annual variability.
[14]
Figure 2.3
| Number of hot summer days in north-west NSW |
Number of frosty winter days in south-central NSW |
Figures not available in Htm Version
(As simulated by the CSIRO regional climate model in which greenhouse
gas concentrations were increased according to the IS92a emissions scenario.)
2.80 CSIRO also modelled potential changes in rainfall. They said that:
Figure 2.4 illustrates the way in which natural variations can obscure
a small overall trend, which in turn masks substantial changes in
the number of extremes. As described in the caption, the panel on
the right indicates that from the middle of this century there is
an increased chance that south-western NSW will receive an amount
of spring rainfall that was regarded as `dry' in the latter part of
the twentieth century. [15]
Figure 2.4
| Simulated spring rainfall over south-western New
South Wales |
The number of dry spring seasons experienced per
20 years. |
Figures not available in Htm Version
(`Dry' is defined as a spring season where rainfall is below that
of the 4th driest year in the period 1961-2000.)
2.81 However, in presenting their results for this modelling, CSIRO
made an important qualification: `The problem for policymakers is that
while these results are plausible, they are from a single experiment
from a regional climate model. Different models are likely to show quantitatively
different changes over the same regions'. [16]
2.82 Making exact predictions for climate change in the Australasian
region is obviously subject to continuing uncertainties, caused by the
difficulty in obtaining regional level resolutions from global climate
models, uncertainty about ENSO patterns, and wide predicted ranges of
rainfall change. However, scientists have been able to isolate probable
changes including: dramatic changes in rainfall levels and intensities,
with a strengthening view that large parts of Australia could become
much drier; damage to the Great Barrier Reef; changes to river flows
and flood frequencies; damage to biodiversity; worsening dryland salination
problems; and resultant damage to important industries such as tourism
and agriculture, and possible damage to built infrastructure through
cyclones.
2.83 The lack of information about the potential costs of climate change
impacts in Australia at both a national and regional level was of serious
concern to the Committee during its inquiry. Although there are some
uncertainties regarding impacts, there has been no attempt by the Government
to translate these impacts into economic and social costs. The Committee
acknowledges that making a better assessment will require progress on
the resolution of regional climate models, and it urges the Commonwealth
Government to devote adequate resources into such research, and into
developing assessments of the possible environmental, social, and economic
impacts of climate change within Australasia. In the Committee's view,
such costs ought to be as much a part of current debates about national
abatement action as the costs associated with reducing emissions.
Stabilising the Global Climate System: The World Abatement Task
2.84 A particularly important issue presented to the Committee was
that of the level at which the global climate system could be realistically
stabilised, and how great a reduction in emissions would be required
to do so. The IPCC has, in the Second Assessment Report modelled a range
of pathways to a stabilisation of global greenhouse gas concentrations
in the atmosphere at various levels: at 450 parts per million (ppmv),
550, 650, 750 and 1000 ppmv. They state that `the steeper the increase
in emissions (hence concentrations) in these scenarios, the more quickly
is the climate expected to change… for a given stabilisation concentration
value, higher emissions in early decades require lower emissions later
on'. [17] A diagram showing possible pathways
to stabilisation is included overleaf.
Figure 2.5
Co-operative Research Centre for Southern Hemisphere Meteorology,
Monash University
Figures not available in Htm Version
2.85 The IPCC lists the temperature increases that would result from
a stabilisation of the climate system at various levels:
- stabilisation at 450 ppmv would see a temperature increase of about
1ºC (a range of between 0.5ºC and 1.5ºC);
- at 650 ppmv, an increase of about 2ºC (between 1.5ºC to
4ºC); and
- at 1000 ppmv, of about 3.5ºC (between 2ºC to 7ºC).
[18]
2.86 These temperature increases would be the result of increasing
concentrations of CO2 alone (which accounts for 60 per cent of
current concentrations, and will increase to 75 per cent by 2100), excluding
other greenhouse gases with much higher forcings, and also excluding
the effects of aerosols (which can cause a counteractive cooling). However,
given the IPCC's statement that the greenhouse forcings of methane and
nitrous oxide would also increase in absolute terms by a factor of between
2 and 3, such temperature estimates may be slightly conservative. [19]
2.87 As discussed earlier, even if the global concentration of emissions
was stabilised at a level of 550 ppmv, sea levels would continue to
rise for many centuries, potentially causing massive social and economic
impacts and presenting enormous challenges for political stability and
adaptation. The IPCC Second Assessment Report states that:
The stabilization of greenhouse gas concentrations does not imply
that there will be no further climate change. After stabilization
is achieved, global mean surface temperature would continue to rise
for some centuries and sea level for many centuries. [20]
2.88 The IPCC's Second Assessment Report discusses the task of stabilisation
separately for the three major greenhouse gases, carbon dioxide, methane
and nitrous oxide. The Committee also heard evidence about the level
of abatement required to stabilise CO2 concentrations.
Methane
2.89 Methane has a high greenhouse forcing (global warming potential,
GWP) of about 21 times that of CO2. However, according to the IPCC,
`atmospheric methane concentrations adjust to changes in anthropogenic
emissions over a period of 9 to 15 years. If the annual methane emissions
were immediately reduced by about 30 Tg CH4 (about 8 per cent of current
anthropogenic emissions), methane concentrations would remain at today's
levels. If methane emissions were to remain constant at their current
levels, methane concentrations (1720 ppbv in 1994) would rise to about
1820 ppbv over the next 40 years. [21] The
CSIRO was optimistic about methane, saying that: `the growth rate of
methane is slowing, and if this trend continues, the concentration of
methane will have stabilised by the first Kyoto commitment period'.
[22]
Nitrous Oxide
2.90 The Second Assessment Report stated that nitrous oxide has a long
lifetime of about 120 years, and that `for the concentration to be stabilised
near current levels (312 ppbv in 1994), anthropogenic sources would
need to be reduced immediately by more than 50 per cent. If emissions
of nitrous oxide were held constant at current levels, its concentration
would rise to about 400 ppbv over several hundred years, which would
increase its incremental radiative forcing by a factor of four over
its current level'. [23]
2.91 The rapid reduction of nitrous oxide emissions obviously has to
be a global priority, and the Committee urges the Government to develop
a strong focus on the reduction of national N2O emissions. Agriculture
is by far the largest N2O emitting sector, with transport, stationary
energy and industrial processes also making smaller contributions. The
major factors influencing N2O emissions in the agricultural sector were
the disturbance of land for tillage, along with biomass burning, the
use of nitrogenous fertilisers and the management of animal wastes.
[24]
Carbon Dioxide
2.92 The IPCC explains that carbon dioxide `has a relatively long residence
time in the climate system - of the order of a century or more'. They
explain that current emissions levels would see an increase of global
atmospheric concentrations to 500 ppmv by 2100:
If net global anthropogenic emissions (ie., anthropogenic sources
minus anthropogenic sinks) were maintained at current levels (about
7 Gt/yr including emissions from fossil fuel combustion, cement production
and land use change), they would lead to a nearly constant rate of
increase in atmospheric concentrations for at least two centuries,
reaching about 500 ppmv (approaching twice the preindustrial
concentration of 280 ppmv) by the end of the 21st century. Carbon
cycle models show that immediate stabilization of the concentration
of carbon dioxide at its present level could only be achieved through
an immediate reduction in its emissions of 5070 per cent and
further reductions thereafter. [25]
2.93 The Second Assessment Report suggests that to restrain atmospheric
concentrations of CO2 to below 550 ppmv (a level the Committee strongly
advocates, given that it would still result in a 1ºC increase in
global mean temperatures, and sea level rises of between 25 and 50 cm
by 2100) would require an enormous effort in greenhouse abatement during
the 21st century:
If the atmospheric concentration is to remain below 550 ppmv, the
future global annual average emissions cannot, during the next century,
exceed the current global average and would have to be much lower
before and beyond the end of the next century. Global annual average
emissions could be higher for stabilization levels of 750 to 1000
ppmv. Nevertheless, even to achieve these latter stabilization levels,
the global annual average emissions would need to be less than 50
per cent above current levels on a per capita basis or less than half
of current levels per unit of economic activity. [26]
2.94 The IPCC also suggests that the relative importance of CO2 to
the global warming problem will increase over time:
The importance of the contribution of CO2 to climate forcing, relative
to that of the other greenhouse gases, increases with time in all
of the IS92 emission scenarios (a to f). For example, in the IS92a
scenario, the CO2 contribution increases from the present 60 per cent
to about 75 per cent by the year 2100. During the same period, methane
and nitrous oxide forcings increase in absolute terms by a factor
that ranges between two and three. [27]
2.95 The Committee heard further evidence from scientists about what
would be required to stabilise the global climate system, and the ideal
level at which to aim to do so. Dr Geoff Jenkins of the UK's Hadley
Centre argued that a level of 550 ppmv, whilst challenging, would avoid
some of the worst potential impacts of climate change:
We have done a recent study looking at impacts of several emission
strategies, both unmitigated emissions - business as usual emissions,
if you like, the sort of thing that IPCC has called the IS95 scenario
emissions - and also emissions which are very much less than that
and would lead to stabilisation of concentrations in the atmosphere
at either 550 or 750 parts per million, over a very long period of
a few hundred years. There are some interesting results from that
on a global basis. So, for example, in the smallest of those emission
scenarios, leading to a stabilisation at 550, we find that over the
course of the next hundred years - as you might expect - because emissions
are lower, then a lot of the impacts are lower. The negative and,
indeed, in some cases the positive impacts on changes in vegetation
and on changes in water resources, run-off from rivers, for example,
changes in food production, crop yield, will be reduced as you reduce
the emissions. That is perhaps not a very surprising result.
What we can also see is that in the very long term, if we adopt a
very low emission scenario approach, then some of the very large changes
such as I have mentioned over the Amazon region - dieback of forests
over the Amazon region - will be avoided even over a 300-year period.
[28]
2.96 Dr Jenkins explained that driving this work was an effort to interpret
Article 2 of the UNFCCC:
The reason for doing some of this work was to look at perhaps trying
to interpret the word `dangerous' that comes out of the UN Framework
Convention on Climate Change, that `dangerous' climate change to be
avoided. Nobody really knows what dangerous means and we were trying
to look at some of these impacts to see if there was any guidance
on either the change in climate or the change in impacts which could
help to define that word. So, if indeed the models are correct - as
I said before, a lot of the results may be very model dependent -
and if we look at some of the changes that we see over Amazonia and
the quite rapid dieback in forests there and define that as a dangerous
climate change, then that sort of thing could be avoided by going
on really quite a low emissions pathway which would stabilise at 550
parts per million. [29]
2.97 The Chairman of the IPCC, Dr Watson, also emphasised the importance
of Article 2 of the UNFCCC as an objective in stabilisation analyses:
If indeed we take seriously the overall objective of the climate
convention Article 2 - that is to say, stabilisation of the atmospheric
concentrations of greenhouse gases and hence eventually stabilisation
of the climate system - one would want to say quite categorically
that the Kyoto Protocol is only a small, albeit very important, first
step towards the ultimate objective of the convention. The reason
for that is very simple: if we were to want to stabilise the earth's
climate, we would have to have global emissions lower than they are
today. [30]
2.98 Dr Watson explained what kind of emissions reductions would be
required to stabilise global concentrations of CO2 at 550 ppmv:
If we were to take, for example, stabilisation at 550 parts per million
of atmospheric carbon dioxide - and let me just remind you that pre-industrial
levels of carbon dioxide were 280 and today we currently have about
360 parts per million - and I am not saying that is the right level,
I am just saying if we did, and that is the target of the European
Union, global emissions of CO2 could go up from today's around seven
to somewhere around eight to nine, or maybe 9½ billion tonnes
per year, over the next two or three decades, and then they would
have to significantly come down. They would have to, as I say, come
down so that by the end of this century we would be roughly where
we are today or less, and over the next 100 years they would have
to decrease to, say, two to three billion tonnes. [31]
2.99 The Committee notes that this amount - 2 to 3 billion tonnes -
would require a fall to emissions to between 30 and 40 per cent of 1990
levels by 2200. Dr Jenkins also offered a view on the possible path
to stabilisation:
There is not a unique pathway of emissions in order to stabilise
concentrations in the atmosphere. The sorts of pathways that IPCC
have come up with in order to stabilise at twice the preindustrial
levels, 500 parts per million, involve allowing a small change up
to maybe nine or 10 gigatonnes per annum globally over the next 100
years or so but then really a quite rapid decrease and eventually,
over a few hundred years, down to levels of maybe 70 per cent cutback
in emissions compared to today's. This is nothing too novel. It has
been known for 10 or 15 years but because of the way the carbon cycle
operates you do need to make dramatic cutbacks in order to stabilise
the atmospheric concentrations. [32]
2.100 The IPCC has also stated that `a range of global carbon cycle
models indicates that stabilisation of atmospheric CO2 concentrations
at 450 ppmv… could be achieved only if global anthropogenic CO2
emissions drop to 1990 levels by approximately 40… years from now,
and drop substantially below 1990 levels subsequently'. [33]
2.101 Professor David Karoly echoed these analyses, stating that: `global
greenhouse gas emissions need to be reduced to about one-third or less
of 1990 levels to stabilise atmospheric concentrations… .That would
need to take place in the future in an environment of increasing population
and increasing energy use, particularly in developing countries. My
estimate is that developed countries, to achieve a global 30 per cent
level - a 70 per cent reduction - are likely to need to reduce their
emissions to around 10 per cent of present emissions levels'. [34]
2.102 In the Committee's view, this is a daunting prospect for Annex
1 countries (given even the 150 to 200 years time frame), but one which
will have to be faced if the worst impacts of climate change are to
be avoided. Professor Karoly emphasised that reductions needed to begin
soon if such a target was to be viable:
… the reductions over business as usual need to start quite
soon - in fact, immediately… [in] the order of 30 per cent reductions
over the next 20 years… Kyoto is an average six per cent reduction
in developed countries only. The Kyoto Protocol will have no noticeable
effect on observed atmospheric carbon dioxide concentrations. [35]
2.103 The Committee notes that this would require a cut in emissions
to 70 per cent of 1990 levels by around 2020. It is a challenging objective,
and underlines the need for Kyoto signatories to begin planning and
implementing their transition to a low emissions economy immediately.
On the other hand, Dr Watson argued that companies such as Shell had
developed scenarios which plausibly suggested that the world could make
a transition to a low carbon economy this century:
The question I think one has to ask is - and I pose it as a question,
not as a policy statement: are there simpler options of more efficient
use of the current energy, more efficient production of current energy
and, where appropriate, decarbonising our energy systems? If one looks
at some of the plausible scenarios of Shell, they show that, by 2050,
one could envisage half the world's energy still coming from fossil
fuels and half the world's energy coming from a mix of renewable energies.
The most contentious part of it, in my opinion, is the use of nuclear
power, but that is a public issue. If, indeed, one had realised the
Shell scenarios and then pushed them out for the next 50 years as
well, one could envisage… where the world would stabilise atmospheric
CO2 at about 550 parts per million. Indeed, I think one can actually
limit projected changes in climate to a very interesting mix of efficiency
and production without just saying that no longer should we have fossil
fuels… . [36]
2.104 Professor Karoly's views, in addition to those expressed by Dr
Jenkins and Dr Watson, give a valuable insight into the scientific context
in which future Kyoto targets will be negotiated. It can be realistically
expected that future targets will be substantially lower than those
for 2008 to 2012, beginning as early as the second commitment period
(2013 or after). This would mean that Australia will need to set its
economy on a path to a national emissions total substantially below
108 per cent of 1990 levels during the second commitment period, with
an expectation that we may need to reduce emissions to around 70 per
cent of 1990 levels by 2030 or possibly earlier.
Scientific Uncertainty and the Precautionary Principle
2.105 The Committee acknowledges that there are a number of areas of
scientific uncertainty in relation to climate change. Principle among
these are the effect of aerosols on greenhouse forcing, the identification
of regional impacts, and the release and sequestration of carbon by
soils and plants. Of some debate has been whether the existence of uncertainty
suggests either a need to delay abatement action, or the adoption of
the precautionary principle, which requires action now while existing
uncertainties are further explored. The precautionary principle is specifically
recognised in the UNFCCC, and it is a principle the Committee strongly
endorses.
2.106 The IPCC states that there are a series of uncertainties, and
advocates further work, in relation to:
- Estimation of future emissions and biogeochemical cycling (including
sources and sinks) of greenhouse gases, aerosols and aerosol precursors
and projections of future concentrations and radiative properties.
- Representation of climate processes in models, especially feedbacks
associated with clouds, oceans, sea ice and vegetation, in order to
improve projections of rates and regional patterns of climate change.
- Systematic collection of long term instrumental and proxy observations
of climate system variables (eg, solar output, atmospheric energy
balance components, hydrological cycles, ocean characteristics and
ecosystem changes) for the purposes of model testing, assessment of
temporal and regional variability, and for detection and attribution
studies. [37]
2.107 The IPCC also explains that the non-linear nature of the climate
system will produce `surprises' that are, by their nature, difficult
to model:
Future unexpected, large and rapid climate system changes (as have
occurred in the past) are, by their nature, difficult to predict.
This implies that future climate changes may also involve `surprises'.
In particular, these arise from the nonlinear nature of the
climate system. When rapidly forced, nonlinear systems are especially
subject to unexpected behaviour. Progress can be made by investigating
nonlinear processes and subcomponents of the climatic
system. Examples of such nonlinear behaviour include rapid circulation
changes in the North Atlantic and feedbacks associated with terrestrial
ecosystem changes. [38]
2.108 Dr Watson also commented on the difficulties of modelling the
impact of the sulphate aerosols. He explained that:
Sulphur actually offsets parts of global warming… firstly, they
are particles and therefore they reflect incoming solar radiation;
and, secondly, they change the optical properties of clouds... we
believe the emissions of sulphur will probably go up for a period
of time, largely because of energy needs and the use of coal in Asia
- largely India and China - but then they will start to decrease.
So, over time, they will be less and less of a cooling offset to the
greenhouse gases. [39]
2.109 Dr Watson warned that sulphur emissions, while suspected of having
a global cooling effect, were otherwise environmentally damaging because
of their role in acid rain:
Sulphur will be controlled independently, in my opinion, of global
warming climate policies, largely because of its local and regional
effects. Indeed,… our latest projections from a special report
are probably slightly less emissions of CO2 than what we had a few
years ago, but much lower emissions of sulphur. The end product will
be either the same or slightly larger projections of climate change.
[40]
2.110 The IPCC's Second Assessment Report also discusses uncertainties
in relation to the overall complexity of not merely the global climate
system and the forcing effects of multiple gases and particulates, but
in relation to the additional stresses provided by human activities:
Although our knowledge has increased significantly during the last
decade,… our current understanding of many critical processes
is limited; and systems are subject to multiple climatic and nonclimatic
stresses, the interactions of which are not always linear or additive.
[41]
2.111 The IPCC also cautions that existing studies were limited in
scope, and that further work should take account of the difficulty of
factoring in very complex dynamic interactions:
Most impact studies have assessed how systems would respond to climate
change resulting from an arbitrary doubling of equivalent atmospheric
carbon dioxide (CO2) concentrations. Furthermore, very few studies
have considered dynamic responses to steadily increasing concentrations
of greenhouse gases; fewer still have examined the consequences of
increases beyond a doubling of equivalent atmospheric CO2 concentrations
or assessed the implications of multiple stress factors. [42]
2.112 It is sometimes said that such uncertainty justifies a delay
of greenhouse abatement action. However, the IPCC has strongly established
that the balance of evidence suggests a discernible human influence
on climate to date, and that greenhouse gas emissions are likely to
cause a range of devastating impacts if they increase unchecked.
2.113 Furthermore, the application of the precautionary principle requires
that action be taken now. The precautionary principle is recognised
in Commonwealth environmental legislation (the Environmental Protection
and Biodiversity Conservation Act 1999 (EPBC Act), in the National
Strategy for Ecologically Sustainable Development, and in the UNFCCC:
- The EPBC Act states, in its section 3A:
- If there are threats of serious or irreversible environmental
damage, lack of full scientific certainty should not be used as
a reason for postponing measures to prevent environmental degradation.
[43]
- Article 3.3 of the UNFCCC commits Parties to:
… take precautionary measures to anticipate, prevent or minimize
the causes of climate change and mitigate its adverse effects. Where
there are threats of serious or irreversible damage, lack of full
scientific certainty should not be used as a reason for postponing
such measures, taking into account that policies and measures to deal
with climate change should be cost effective so as to ensure global
benefits at the lowest possible cost. [44]
2.114 The IPCC makes a strong argument for the application of the precautionary
principle in the face of scientific uncertainty, in its advice to policymakers
on adaptation and mitigation. It makes the point that it is important
`to consider these uncertainties in the context of information indicating
that climateinduced environmental changes cannot be reversed quickly,
if at all, due to the long timescales associated with the climate
system':
Decisions taken during the next few years may limit the range of
possible policy options in the future because high nearterm
emissions would require deeper reductions in the future to meet any
given target concentration. Delaying action might reduce the overall
costs of mitigation because of potential technological advances but
could increase both the rate and the eventual magnitude of climate
change, hence the adaptation and damage costs.
Policymakers will have to decide to what degree they want to take
precautionary measures by mitigating greenhouse gas emissions and
enhancing the resilience of vulnerable systems by means of adaptation.
Uncertainty does not mean that a nation or the world community cannot
position itself better to cope with the broad range of possible climate
changes or protect against potentially costly future outcomes. Delaying
such measures may leave a nation or the world poorly prepared to deal
with adverse changes and may increase the possibility of irreversible
or very costly consequences. [45]
Greenhouse Science and Greenhouse Sceptics
2.115 The Committee acknowledges that there exists a small minority
of scientists and others who strongly dispute the claims of the IPCC
about current and future climate change. Within Australia, a small group
was established in mid-2000 under the chairmanship of former Hawke Government
minister, the Hon Peter Walsh AO, known as the Lavoisier Group. The
Group publicly opposes the IPCC's conclusions about climate change and
the Kyoto Protocol.
2.116 The Committee received a submission from the Lavoisier Group
in June 2000, some 8 months after the closing date for submissions in
1999, and a few days before its final substantive hearing. Given the
lateness of the submission, the Committee was not able to hear evidence
from and question the claims of the Group. The submission was primarily
a critique by the American meteorologist Professor Richard Lindzen of
the submission made to this inquiry by the CSIRO. In order to deal properly
with its substantive claims, a response to the submission was sought
from the CSIRO. As at the conclusion of its inquiry, the Committee had
not received a response from CSIRO, who explained that that they were
busy preparing a submission to, and hosting a visit of, the Joint Standing
Committee on Treaties' Inquiry into the Kyoto Protocol. The Lavoisier
Group submission is publicly available from the secretariat of this
Committee. [46]
2.117 A similar submission was made by the consultant Mr Bob Foster.
He claimed that:
- the Kyoto Protocol itself constitutes an environmental threat because
it draws funds away from other environmental problems in favour of
a `long term, and as yet unsubstantiated threat';
- IPCC reports `take the implausible line that climate change is driven
by changes in atmospheric composition alone, rather than by ice, oceans
and atmosphere acting in concert', and that climate change is a gradualist
system amenable to computer modelling unaffected by extreme non-atmospheric
effects;
- the `only way we have of judging the numerical models used for climate
change forecasting is to require them to hindcast the known climate
record. Despite IPCC claims to the contrary, they fail the test'.
[47]
2.118 In reference to Mr Foster's first claim, the Committee does not
support the claim that climate change is an `as yet unsubstantiated
threat'. In the Committee's view, the funds dedicated to addressing
climate change do not, therefore, constitute an environmental threat
as claimed.
2.119 The Committee does not believe that Mr Foster's second claim
is tenable. Evidence from a wide range of climate change scientists
emphasised that climate change was the result of complex system which
included oceans, land and atmospheric factors. Understanding the interaction
of such factors is a priority of research, including carbon cycle feedbacks
and ocean atmosphere interactions. As Dr Jenkins of the Hadley Centre
told the Committee:
The models at the moment - the sort of model we run, the models that
you run at CSIRO and BMRC in Australia - couple together the ocean,
the atmosphere and the land surface. That needs to be coupled because
there are a lot of interactions between those elements of the climate
system which are very important in determining feedbacks which can
either accentuate or reduce the global warming, or the radiative forcing
- the heating effect if you like - of additional man-made gases. So
it is very important to link all those parts of the climate system
together. [48]
2.120 Similarly, the Committee is not convinced by Mr Foster's claim
that climate change forecasting has failed the `hindcast test'. The
Committee received evidence from scientists about their efforts to `hindcast'
known atmospheric changes using their models. These show that models
are having some success in this regard, and that naturally observed
changes such as solar radiation and volcano activity cannot account
for temperature change of the past 50 years. For example, the Hadley
Centre has specifically sought to model backwards, and to incorporate
known external events rather than smooth out climate. Their new model,
HADCM3, they claimed `has a better representation of climate and climate
change than previous models. It has a much better resolution, for example,
in the ocean, than most models It does not use so-called flux adjustments
to get the climate into a stable condition with low drift':
We use that to try and simulate changes over the past 50 years due
to factors which are naturally forced - in other words, largely solar
and volcanic - and factors which are human. These are the greenhouse
gas rise, the rise in aerosol, changes in ozone and so on. Then we
look at the model without any changes at all, either natural or human,
to look at the natural internal variability of climate. We find that,
only by incorporating all three of those types of changes - in other
words, the internal changes, the solar, the volcanic and the human
activities - can we really get a good representation of the changes
that have occurred over the past 50 years or so. [49]
2.121 Dr Jenkins further explained the results that were arising from
this approach:
If we do it just with the natural activity alone, for example the
way in which volcanic activity has been quite high over the past two
or three decades, and the way that solar changes may have risen to
a certain extent but have not been as great as this, we find that
cannot give the sort of signal of quite rapid temperature change that
has occurred particularly since about 1975. Because the forcing agents
have gone down over that period in total that cannot simulate the
sort of change that has occurred over that period. But when we include
the effect of the human activities increasing greenhouse gases, despite
increases in aerosol, we do find we are able to simulate reasonably
well the temperature change on a global average basis that has occurred
over that period. [50]
2.122 Although a response has not been received from the CSIRO, the
Committee did receive evidence relating to one of Professor Lindzen's
central criticisms - that satellite data support an argument that `there
is no evidence of any warming in the atmosphere', and that there are
also problems in the surface record such as variations due to urban
concentrations, coverage over oceans and `the fact that much of the
warming of the 90s comes from Siberia where, since the breakup of the
Soviet Union, data quality control has been, to be generous, inadequate'.
[51]
2.123 CSIRO's argument in regard to satellite observations was that:
There is likely to be a real difference between the warming at the
earth's surface and the lowest five miles of the atmosphere. This
difference was ascribed to three factors: the thinning of the ozone
layer, emissions from the Mt Pinatubo volcanic eruption and greenhouse
gases.
Additionally, comparing the two sets of measurements is complicated
because the observations are different. The ground-based measurements
are taken at points usually about 2 m above the earth surface. The
satellite observations represent the temperature in a layer of the
atmosphere in the region 1,500 – 10,000 m above the Earth's surface.
It should also be noted that the satellite record covers the period
from 1979, whereas the ground-based record contains data from about
1860. It is important to have available the longer record in order
to evaluate the extent to which recent trends might be due to decadal-scale
natural variations in planetary temperature. [52]
2.124 The Hadley Centre maintained that other upper atmosphere records
did not show the same conflict with ground records:
You may be aware that particularly in America there has been some
controversy as to the extent to which changes in global warming at
the surface disagree with measurements of warming made by satellites
higher in the atmosphere at about a height of maybe three or five
kilometres. What we have done is to not use satellite measurements
but measurements from weather balloons and look at the trends in temperature
that have occurred since about 1960 to the present day in the atmosphere.
That has shown us that the overall trends in temperature in the atmosphere
have not been very much different from those at the surface which
sees quite a clear warming in the atmosphere reasonably similar to
that at the surface overall over that period. [53]
2.125 The Centre was quite open with the Committee about the uncertainty
generated by upper atmosphere observations, but stressed that it did
not negate the plausibility of the warming shown in the surface record
and in the atmosphere:
What we however see is that there are differences between the atmosphere
warming and the surface warming in periods of a few years or a decade
long which we do not understand. The atmosphere does not warm as quickly
as the surface does in those periods. We do not fully understand the
reasons for that. We believe there is work to be done in that area
to ensure that the models can simulate that correctly. That would
then increase our confidence in the models. There is an issue there
that still has to be resolved, but it does not negate the fact that
the warming at the surface is very robust and that we believe the
warming of the atmosphere is quite substantial as well. [54]
2.126 The Hadley Centre also cited work which compared a wide range
of evidentiary data on past climate. This data buttressed surface records
and suggested that temperature changes over the past 100 years were
out of the ordinary:
Another area which is not our work but which I think is a very strong
pointer is the work done by Michael Mann at the University of Massachusetts.
There is also some work from Keith Briffa and Phil Jones at the University
of East Anglia in England. What they have done is to reconstruct paleo
records going back over the last thousand years, largely in the Northern
Hemisphere. When they put these paleo records from tree rings, ice
cores, corals and so on all together to look at the temperature change
over the past thousand years, despite the very large uncertainties
in these measurements, you can see a reasonably clear trend of very
little change or perhaps a small decrease in temperature over that
period.
That is until the last 100 years or so, when there is a very significant
upward trend over that period, both in the proxy data and in, obviously,
the instrumental records that we all know about. So again to see that
diagram does make it very clear, if indeed you believe the proxy data
of that period, that what is happening over the last 50 or 100 years
is unusual in the context of the last thousand years or so. Of course,
being unusual does not prove that it is human activities that are
to blame, but it does very clearly show that there has been a detection
of climate change. On the attribution question, to summarise, as I
said at the beginning: the more work we do - not just ourselves but
other people as well - the more the pointers are in the direction
of a substantial proportion of the temperature rise over the last
50 years being attributable to human activities. [55]
2.127 Dr Robert Watson, Chairman of the IPCC also strongly asserted
that observed climatic changes accorded with those expected from global
warming:
Indeed, if you ask the question, `What would you expect in a warmer
world is caused by greenhouse gases?' you would expect warmer temperatures.
We have obviously observed that. You would expect the night time temperatures
to have warmed more than day time temperatures; hence there will be
less of a diurnal variability. We have observed that. We have observed
land warming faster than oceans. We have seen that. We would expect
to see more precipitation globally. We have seen that. We would expect
to see more precipitation falling in heavy precipitation events. We
have observed that. We have also seen what we would call the right
latitudinal distribution of temperature changes. So while the models
and the data are not in perfect accord there are lots of similarities
to suggest that the observed changes in climate have the right fingerprint
of human induced activities, not natural phenomena. So we do see a
pattern where we would now say the likely reason for the changes in
climate are at least in part due to human activities. [56]
2.128 In the Committee's view, climate change scientists have been
scrupulously honest about areas where uncertainty exists, and are making
credible efforts to reduce that uncertainty through further research.
Existing uncertainties (as discussed above) do not lead to a conclusion
that concern about both existing and potential climate change is unwarranted
or scientifically invalid. IPCC reports are a consensus of hundreds
of scientists from around the globe, are exhaustively peer reviewed,
and the texts are carefully examined by UNFCCC member governments before
they are made public. In such a context, the Committee is confident
that human induced climate change is a fact, and that the various IPCC
scenarios (given various estimates of emissions, population and economic
growth) are plausible. In the face of uncertainty, as noted earlier,
the precautionary principle should be followed.
2.129 The Australian Government has also stated that it accepts the
scientific consensus established by the IPCC. The Chief Executive of
the AGO, Ms Gwen Andrews, emphasised to the Committee that accepting
the scientific consensus on climate change was important in developing
a long term response to the problem:
This is the time now to start demonstrating that this is a serious
matter. Certainly the Government takes very seriously the commitment
it has made internationally with regard to the UN framework convention
on climate change and its commitment to the Kyoto Protocol and its
implementation. The extent of the change that can be achieved in the
short term and the targets that have been set are not the end of the
story. It is important that the public understand, as Mr Carruthers
said, that this is a long term issue and that there will be a long
term response….It is important that the public accept the science
and the strengthening consensus on the science. [57]
Recommendation 1
The Committee recommends that the Commonwealth Government make a
strong public statement on its position on the science of climate change,
and initiate an awareness raising campaign to communicate the issue
of climate change to the broader community.
Understanding Regional Climate Change: Funding and Research Issues
2.130 Australia is at the leading edge of global atmospheric and climate
change research, with a range of prominent scientists involved in the
drafting of IPCC assessments and developing regional climate change
models. However, current levels of funding to other areas of research
are inadequate to ensure a better understanding of potential climate
change in this region, and its impacts on communities, the environment
and economic activity.
2.131 Since the late 1980s Australian Governments have spent approximately
$55 million on climate change research. In the 1999-2000 budget the
Government committed an additional $14 million over four years for the
Greenhouse Science Program which aims to improve global, regional and
national understanding of climate change, potential impacts on Australia,
and options for adaptation and mitigation. [58]
2.132 The Greenhouse Science Advisory Committee (GSAC) recommends the
additional application of $10 million per year in their report, Advancing
Greenhouse Science Strategy and Business Plan 2000-2005, which was
submitted to the Commonwealth Government for consideration in November
1999. The Government has not yet made a decision in regard to these
funds, which the GSAC argues would be `a minimum investment to support
Australia's national greenhouse commitments. The funds would target
gaps in research that need strengthening in the national interest rather
than solving all the problems or satisfying all scientific interests'.
[59]
2.133 The Committee is strongly of the view that much greater effort
and resources need to be directed to understanding the potential impact
of climate change on the Australasian region. Such efforts will be crucial
to efforts to mitigate potential climate change and adapt to inevitable
climate change. They will also help to clarify our national interests
in ensuring that a serious global effort to stabilise climate occurs.
2.134 The Director of the CSIRO Atmospheric Research Division, Dr Graeme
Pearman, explained the growing demands on Australian scientists:
The amount of science that is required in order to respond to the
so-called greenhouse issue today, in the year 2000, is so much different
than it was in the year 1990. That is because we are not only required
to now continue to develop the underpinning science, which is really
mainly pointed at predicting at a regional level the kinds of things
that people really need to know, but we are also being asked as a
scientific community to provide guidance on issues of sequestration,
technological innovation and alternatives of impacts and adaptation
and so on. These are areas in which the commitment of the science
community has been there but the resources have been very light. So
I think there is a question of insufficient resources to do all of
those areas. [60]
2.135 Dr Pearman stated that while funding for the underpinning science
on regional impacts was probably adequate, he intimated that these extra
areas were lacking:
With respect to the underpinning areas of science, the Government
has a commitment to maintaining the $4 million a year support to that
research over the next triennium. As long as that continues, I think
we are reasonably well based, remembering of course that science is
becoming, like everything else, dearer to do. [61]
2.136 However, a former CSIRO scientist, Dr Albert Pittock, expressed
serious concerns about the ability to continue regionally focused work.
He praised CSIRO's efforts to develop global climate models, but added
that there was no certainty that such progress could be continued:
The climate model in CSIRO went from non-existence about 15 years
ago to now being one of the three or four most reputable in the world.
I think we can be very proud of that. It was as the result of a lot
of investment by the Government in supercomputing facilities, but
that is a big gain for Australia for other reasons. The certainty
that we can keep up is not there at the moment. If you come to the
more local modelling, the nested modelling and the climate impacts
and adaptation work, then Federal funding has pretty well dried up
in the last several years. Most of our funding now comes from state
governments and some other instrumentalities, so we are particularly
getting work in Queensland and New South Wales and to some extent
Victoria. It has been a big struggle… . We have, I think, some
of the best scientists in the world. The risk assessment vulnerability
work is being pioneered by somebody in our lab who has only a temporary
position because we do not have the certainty to employ them on a
more permanent basis. [62]
2.137 Dr Pearman also admitted that there was a dearth of regionally
focused predictions:
There are two levels of impact assessment. There is one level in
which you effectively take some scenario - potential future - and
you test the response of a component or sector of the society. A lot
of that has been done in Australia… . The second level…
actually trying to make a real prediction and saying, even with the
uncertainties of the projections of the gases and the climate response,
can we then say what will actually happen with some uncertainty limits
drawn on it. There is virtually none of that being done in this country.
[63]
2.138 Dr Pittock argued that funding in this area needed to be increased:
in broad terms it would need to be in the multimillion dollar category,
and not just for the CSIRO. There needs to be funding of a lot of
regional groups that will have a local knowledge and interest in their
own region and be in contact with local stakeholders. [64]
2.139 Professor Garth Paltridge, Director of the Antarctic Cooperative
Research Centre, argued that, while basic science was reasonably well
resourced in Australia, research on the potential impacts in Australasia
was seriously lacking:
What is lacking is good, solid, hard, disciplined research into the
impact of climate change on society and on productivity of agriculture
and so on. That has always been an area where people tend to wave
their hands a lot, but in terms of the actual hard scientific research
that is done on the subject of the potential impact of climate change,
there is very little indeed that you would say comes out of the reputable
scientific journals. [65]
2.140 The Antarctic CRC's Professor William Budd, also said that work
was also needed on adaptation, given that irreversible climate change
was likely to occur, whatever efforts were made to reduce emissions
in the future:
There is another area that also needs attention and that is adaptation.
The things that I spoke about with climate change and changes in the
ocean appear to be going ahead, even in spite of the best efforts
of reducing emissions. If we are concerned about these long term changes
then we need to think about adaptation. For example, within Australia
what we see is the reduction in rainfall over the long term but, in
spite of that, still similar frequencies of floods but greater frequencies
of the drier episodes. We need to learn how to adapt to that because
this is happening on the decadal and century time scales. It means
that these things need to be taken into account in terms of land planning
and water usage and all the other agricultural and industrial activities.
The main thing is that from the modelling we get a good idea of the
time frame in which these things can be expected to develop. [66]
2.141 Professor David Karoly, Director of the Cooperative Research
Centre for Southern Hemisphere Meteorology at Monash University, strongly
argued that there was a serious gap in research and training opportunities
for climate change science in Australian universities:
There have been either direct or indirect reductions in funding for
university training groups in atmospheric and climate sciences associated
with changes in government policy for university education. This has
led to significant reductions in the training of climate specialists
and professionals with expertise in climate change and climate change
impacts. In fact, it has probably led to a 50 per cent reduction in
academic staff in these areas in the last 10 years. This seems to
be somewhat inconsistent with an apparent need for increased scientists
and professionals with an understanding of climate change and climate
change impacts. [67]
2.142 Professor Karoly told the Committee that there is no department
of climate or atmospheric science at any university in Australia, and
that existing co-operative research centres (CRCs) were also under substantial
funding pressures:
A department of atmospheric and climate sciences could or should
be established. There have been two significant groups established:
the Antarctic CRC that you would be familiar with, in Hobart, has
been established with cooperative research centre funding and my own
cooperative research centre has been established. My own cooperative
research centre [Monash University] will be closing in June this year
and the funding for the Antarctic CRC [University of Tasmania] is
essentially going to run out in 2003 unless significant changes are
made. Those are the two largest groups in climate sciences in Australia
at present and both of them are due to close within three years. [68]
2.143 The Committee is very concerned by this evidence. It is of the
view that Australia needs to continue to participate in international
scientific efforts at a high level, to ensure that a growing body of
researchers across a range of disciplines is being trained for future
efforts, and in particular, to significantly increase efforts to understand
the nature and impact of climate change on this region to adequately
inform policy development.
Recommendation 2
The Committee recommends that adequate funding be provided to:
- enable the CSIRO to continue work on the underlying science of
climate change;
- work on the nature of potential impacts of climate change in
the Australasian region possibly through new or existing CRCs; and
- work on the potential social, economic and environmental costs
of the impacts of climate change on Australia, particularly at a regional
level.
Recommendation 3
The Committee recommends that Australian universities be encouraged
to establish departments and courses that focus on atmospheric or climate
change science, and that funding be provided to support such initiatives.
Australian Democrats Recommendation 1
The Australian Democrats recommend that a minimum of $100 million
in funding should be provided over the next four years for climate change
science.
Conclusions
2.144 The Committee accepts the growing consensus that human activity
is leading to increasing atmospheric concentrations of greenhouse gases
with significant changes to global climate predicted as a result.
2.145 Notwithstanding existing uncertainties, it is clear that predicted
climate change will have severe implications for Australia, which is
already subject to drought, El Nino/La Nina, tropical cyclones and extremes
of climate. Coastal communities and low-lying areas will be particularly
vulnerable and changes to temperature and rainfall could affect biodiversity
and ecological communities, agricultural systems, flooding patterns
and river flows, and worsen drought and dryland salinity. Increases
in sea temperatures could cause irreversible damage to coral reefs.
2.146 Australia has a strong dependence on climate-vulnerable industries
such as agriculture and tourism, and is the custodian of a vast array
of unique biodiversity, much of which is recognised in national parks
and World Heritage Listed areas.
2.147 Scientists have already identified emissions reduction pathways
that would stabilise the global climate system at global CO2 concentrations
of around 550 parts per million, which could pre-empt much damaging
climate change. While challenging, these reductions are achievable if
concerted global efforts begin now.
2.148 In the Committee's view, Australia has a clear national interest
in seeing the global community work towards stabilising the climate
system. If predicted climate change does occur, it will have significant
social, economic and environmental implications for Australia.
2.149 The emission reduction pathways outlined by scientists and the
IPCC, to stabilise atmospheric concentrations of greenhouse gases, also
indicate a need for Australia to begin long term planning. Such pathways,
which may require a global emissions reduction of 70 per cent within
150 to 200 years, are likely to be reflected in future global responses.
2.150 The Committee concludes that the balance of evidence strongly
suggests that Australia will be very negatively affected by climate
change given the size of its land mass and its long coastline, its current
extremes of climate, its vulnerability to cyclones and the El Nino/La
Nina cycle, its existing problems with soil salinity, and its economic
dependence on agriculture and tourism.
Footnotes
[1] Intergovernmental Panel on Climate Change,
Special Report on Emission Scenarios, A Special Report of Working
Group III, May 2000.
[2] Dr Barrie Pittock, Submission 220, p 4.
[3] Dr Barrie Pittock, Submission 220, p 4.
[4] Dr Bryan Jenkins, Proof Committee Hansard,
Perth, 17 April 2000, p 454.
[5] Dr Barrie Pittock, Submission 220, p 4.
[6] Dr Barrie Pittock, Submission 220, pp
5-6.
[7] Mr Michael Rae, Proof Committee Hansard,
Sydney, 23 March 2000, p 445.
[8] CSIRO, Submission 206, p 2470.
[9] CSIRO, Submission 206, p 2470.
[10] Official Committee Hansard, Canberra,
9 March 2000, p 36.
[11] CSIRO, Submission 206, p 2470-71.
[12] Proof Committee Hansard, Canberra,
22 June 2000, p 743.
[13] CSIRO, Submission 206, p 2471.
[14] CSIRO, Submission 206, p 2471.
[15] CSIRO, Submission 206, p 2472.
[16] CSIRO, Submission 206, p 2472.
[17] Intergovernmental Panel on Climate Change,
IPCC Second Assessment Synthesis of Scientific-Technical Information
Relevant to Interpreting Article 2 of the UN Framework Convention on
Climate Change, clauses 4.6-4.8.
[18] Intergovernmental Panel on Climate Change,
IPCC Second Assessment Synthesis of Scientific-Technical Information
Relevant to Interpreting Article 2 of the UN Framework Convention on
Climate Change, Figure 1.
[19] Intergovernmental Panel on Climate Change,
IPCC Second Assessment Synthesis of Scientific-Technical Information
Relevant to Interpreting Article 2 of the UN Framework Convention on
Climate Change, clauses 4.16, Figure 1.
[20] Intergovernmental Panel on Climate Change,
IPCC Second Assessment Synthesis of Scientific-Technical Information
Relevant to Interpreting Article 2 of the UN Framework Convention on
Climate Change, clause 4.18.
[21] Intergovernmental Panel on Climate Change,
IPCC Second Assessment Synthesis of Scientific-Technical Information
Relevant to Interpreting Article 2 of the UN Framework Convention on
Climate Change, clause 4.13.
[22] CSIRO, Submission 206, p 2459.
[23] Intergovernmental Panel on Climate Change,
IPCC Second Assessment Synthesis of Scientific-Technical Information
Relevant to Interpreting Article 2 of the UN Framework Convention on
Climate Change, clause 4.14.
[24] The Australian Greenhouse Office, National
Greenhouse Gas Inventory: Analysis of Trends and Greenhouse Indicators
1990-98, pp 9, 54-55.
[25] Intergovernmental Panel on Climate Change,
IPCC Second Assessment Synthesis of Scientific-Technical Information
Relevant to Interpreting Article 2 of the UN Framework Convention on
Climate Change, clause 4.6.
[26] Intergovernmental Panel on Climate Change,
IPCC Second Assessment Synthesis of Scientific-Technical Information
Relevant to Interpreting Article 2 of the UN Framework Convention on
Climate Change, clause 4.10.
[27] Intergovernmental Panel on Climate Change,
IPCC Second Assessment Synthesis of Scientific-Technical Information
Relevant to Interpreting Article 2 of the UN Framework Convention on
Climate Change, clause 4.16.
[28] Official Committee Hansard, Canberra,
9 March 2000, p 25.
[29] Official Committee Hansard, Canberra,
9 March 2000, p 25.
[30] Official Committee Hansard, Canberra,
9 March 2000, p 40.
[31] Official Committee Hansard, Canberra,
9 March 2000, p 40.
[32] Official Committee Hansard, Canberra,
9 March 2000, p 26.
[33] IPCC Working Group 1, Summary for
Policymakers: The Science of Climate Change, http://www.ipcc.ch/pub/arsum.htm
(01/09/00), p 1.
[34] Official Committee Hansard, Canberra,
9 March 2000, p 40.
[35] Official Committee Hansard, Canberra,
9 March 2000, pp 43-44.
[36] Proof Committee Hansard, Canberra,
9 March 2000, p 38.
[37] IPCC Working Group 1, Summary for
Policymakers: The Science of Climate Change, http://www.ipcc.ch/pub/sarsum1.htm,
(01/09/00).
[38] IPCC Working Group 1, Summary for
Policymakers: The Science of Climate Change, http://www.ipcc.ch/pub/sarsum1.htm
(01/09/00).
[39] Official Committee Hansard, Canberra,
9 March 2000, p 37.
[40] Official Committee Hansard, Canberra,
9 March 2000, p 37.
[41] IPCC Working Group II, Summary for
Policymakers: Scientific-Technical Analyses of Impacts, Adaptations
and Mitigation of Climate Change, Part 3.
[42] IPCC Working Group II, Summary for
Policymakers: Scientific-Technical Analyses of Impacts, Adaptations
and Mitigation of Climate Change, Part 3..
[43] Environmental Protection and Biodiversity
Conservation Act 1999, section 3A, p 4.
[44] Cited in Intergovernmental Panel on
Climate Change, IPCC Second Assessment Synthesis of Scientific-Technical
Information Relevant to Interpreting Article 2 of the UN Framework Convention
on Climate Change, clause 1.10.
[45] IPCC Working Group II, Summary for
Policymakers: Scientific-Technical Analyses of Impacts, Adaptations
and Mitigation of Climate Change, Part 2.
[46] The Lavoisier Group, Submission 222.
[47] Bob Foster Consultancy, Submission 36.
[48] Official Committee Hansard, Canberra,
9 March 2000, p 23.
[49] Official Committee Hansard, Canberra,
9 March 2000, p 21.
[50] Official Committee Hansard, Canberra,
9 March 2000, p 21.
[51] The Lavoisier Group, Submission 222,
pp 2870, 2874.
[52] CSIRO, Submission 206, p 2462.
[53] Dr Geoff Jenkins, Official Committee
Hansard, Canberra, 9 March 2000, pp 23-24.
[54] Dr Geoff Jenkins, Official Committee
Hansard, Canberra, 9 March 2000, p 24.
[55] Dr Geoff Jenkins, Official Committee
Hansard, Canberra, 9 March 2000, p 22.
[56] Official Committee Hansard, Canberra,
9 march 2000, p 34.
[57] Official Committee Hansard, Canberra,
22 June 2000, p 705.
[58] The Australian Greenhouse Office, Submission
169, p 1703; and Greenhouse Science Advisory Committee, Advancing
Greenhouse Science Strategy and Business Plan 2000-2005, November
1999, p 5.
[59] Greenhouse Science Advisory Committee,
Advancing Greenhouse Science Strategy and Business Plan 2000-2005,
November 1999, p 2.
[60] Proof Committee Hansard, Melbourne,
20 March 2000, p 122.
[61] Proof Committee Hansard, Melbourne,
20 March 2000, p 122.
[62] Proof Committee Hansard, Canberra,
22 June 2000, p 747.
[63] Proof Committee Hansard, Melbourne,
20 March 2000, p 133.
[64] Proof Committee Hansard, Canberra,
22 June 2000, p 747.
[65] Proof Committee Hansard, Hobart,
5 May 2000, p E495.
[66] Proof Committee Hansard, Hobart,
5 May 2000, p E495.
[67] Proof Committee Hansard, Canberra,
9 March 2000, p 40.
[68] Proof Committee Hansard, Canberra,
9 March 2000, p 41.