Download A safe climate scenario

still
A safe climate is possible
but only if we change the way we campaign
Philip Sutton, Manager, RSTI
28 June 2017
(First released Nov 2013)
/ Version 1e
The latest version of this paper can be downloaded from:
http://www.green-innovations.asn.au/RSTI/A-safe-climate-is-still-possible.pdf
Contents
Introduction .....................................................................................................................................1
Where did we hope to be on climate action in 2013? ......................................................................1
Where are we in fact with global warming now? ............................................................................2
“+2ºC” is now “+1ºC” .............................................................................................................................................. 2
Extreme weather events are already dangerous........................................................................................................ 3
Too late for +2ºC? Is it now on to +4 ºC or +6ºC? ................................................................................................... 5
But +2ºC is not the relevant threshold anymore and we can’t live with +4ºC or +6ºC, so what should we do? ...... 7
Rethinking the climate goal – from “avoiding dangerous climate change” to “restoring a safe
climate fast”. ....................................................................................................................................7
Restoring a safe climate fast and avoiding amplified extreme weather events ...............................9
No longer a ‘carbon’ budget .................................................................................................................................... 9
Zero global net emissions......................................................................................................................................... 9
Drawdown of CO2 .................................................................................................................................................. 11
Solar radiation management? ................................................................................................................................. 12
The three technical strategies for restoring a safe climate...................................................................................... 14
A safe climate scenario ..................................................................................................................14
A new mode of campaigning .........................................................................................................14
Conclusions ...................................................................................................................................15
Follow up .......................................................................................................................................15
Summary of the paper’s main points .............................................................................................15
Key terms .......................................................................................................................................16
Climate science information ..........................................................................................................16
The science of global temperature ......................................................................................................................... 16
The history of the earth’s temperature ................................................................................................................... 18
Sea levels ............................................................................................................................................................... 21
References .....................................................................................................................................21
Introduction
This paper offers a two-part argument that:
(a) the restoration of a safe climate is still possible and as a consequence, most of the
predicted catastrophic impacts of climate change can be avoided, but
(b) this can only be achieved if we make very substantial changes to how we campaign on
climate change.
The paper will be used initially as background for face-to-face discussions and will be refined in
the light of those discussions. When the paper is ‘good enough’ to stand alone it will be
distributed widely.
Where did we hope to be on climate action in 2013?
Many people in the climate movement hoped that the world would adopt an effective action
protocol at the Copenhagen Conference in 2009 and that the US, under the leadership of Barak
2
Obama, would adopt an emissions trading system through the passage of the proposed
Waxman-Markey legislation.
As a result of these developments it was hoped that the world would at last pick up pace on
cutting emissions - with the aim of achieving a 60% to 80% reduction in greenhouse gas
emissions by 2050, in order to have a 50:50 chance of halting warming at or under +2ºC1 with
the final CO2 level in the atmosphere being no more than 450 parts per million (compared to the
current level of 395 ppm2)
Under this hoped-for scenario developed countries would cut emissions hard, but poorer
countries would be able to take a few decades longer to adopt a low carbon economy before
using up a ‘carbon budget’ of permissible greenhouse gas emissions. This dual-track approach
was known as the ‘contraction and convergence’ strategy.
But these hopes have not been realised.
Where are we in fact with global warming now?
Here is the reality that we are now living with:
“+2ºC” is now “+1ºC”
The IPCC Third Assessment Report (2001) contained an analysis of the threats posed by climate
change – summarised in what has come to be called the “burning embers” diagram. While the
analysis did not overtly recommend +2ºC (compared to the 1990 temperature3) as the upper limit
on warming this was the conclusion that many scientists and others drew from the data.
In 2009 this impact analysis was updated by Smith et al. – see the diagram below.
It will come as no surprise to people who have kept an eye on climate science that a great deal of
the new climate science information on actual and expected impacts was “worse than anyone
had previously expected”. Impacts of climate change were being found to be more severe at
lower temperatures, so impacts expected decades, often many decades, into the future were
occurring now. When the new data were integrated into the new “burning embers” diagram it
was found that the threshold of clearly dangerous climate change had shifted from +2ºC to +1ºC
above the 1990 temperature.4
By 2012, the average world temperature was about half a degree above the 1990 level5 and half
way to this new threshold.
1
This cap was adopted by the European Union in 1996 and reaffirmed in 2003, 2005 and 2007. It was adopted
globally at the Copenhagen Conference in 2009 (with a caveat promoted by the alliance of vulnerable states
that a new, lower cap [+1.5ºC] be investigated) – and a requirement to hold the temperature increase below
+2ºC. (ie. not a 50:50 chance). (The 2009 Copenhagen Accord did not say that the base year for the
temperature increases was however.)
2
See reference for Mauna Loa CO2, 2013
The temperature in 1990 was about +0.3ºC above the 1850 preindustrial temperature.
4
But the international negotiations still focused on a +2ºC threshold due to diplomatic inertia.)
5
Compared to the (1850) preindustrial reference, the earth has already warmed by +0.8ºC.
3
3
Revised ‘Burning Embers’ diagram
(From Smith et al., 2009)
Extreme weather events are already dangerous
The last decade or so has seen, across the world, an epidemic of extreme weather events that has
broken records for severity. For example the 1998 world wide coral bleaching, the European
heatwave of 2003, the Southeast Asian bushfires of 2007, the 2009 heat wave and bushfires in
southern Australia, the 2010 northern hemisphere events (heatwaves, Russian bushfires, flood in
Pakistan and China) and the 2012 heatwave in the US.6
The food shortages created by the 2010 extreme weather events are credited with being a key
catalyst for the uprisings known as the Arab Spring.
These events suggest very strongly that the earth has now moved into the era of dangerous
climate change.
6
See the Climate Nexus report: Climate Signals: Extreme Weather Guide. It sets out current scientific knowledge
about the influence of climate change on current extreme weather events.
4
(From: Millennium Ecosystem Assessment: http://www.unep.org/maweb/ )
(The data presented in this graphic covers a period prior to the ending of the long drought in Australia.)
(From: Millennium Ecosystem Assessment: http://www.unep.org/maweb/ )
For a long time climate scientists were very reluctant to say that any particular climate event was
‘caused by climate change’. The most that they were prepared to say was that extreme events
were consistent with expectations for a climate changed world.
More recently some respected climate scientists (eg. Kevin Trenberth, James Hansen) have
begun to argue that all weather is now affected by climate change. That is, we don’t have a mix
of many normal events and some climate change events. Instead, we have a naturally highly
variable weather pattern (as is always the case for naturally chaotic weather systems) shifted in
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the direction of higher temperatures – giving rise to a higher incidence of extreme weather
events.7
It is worth bearing in mind that the temperatures, and the attendant extreme weather events, that
we are experiencing now (2013) are the result of full warming from about 1980. This is because
it takes a number of decades for any particular quantity of greenhouse gases to fully heat the
upper layers of the oceans that dominate the temperature of the atmosphere. So unless a lot of
CO2 is taken out of the air fast and/or the earth is cooled through reflecting some sunlight to
space, there will be very significant further warming and therefore a worsening extreme weather
as a result of the greenhouse gases already in the air.8
Given that current climate change is very substantially caused by human environmental impacts,
it means that the worsened burden of extreme weather events is caused by humans. Were it not
for the desensitising psychological conditioning we have received over the last two decades as a
result of being alerted to the risk of deeper future civilisation-ending-climate-change, we would
almost certainly see the current increased incidence of extreme weather events as grounds in
their own right for taking urgent and powerful action.
Too late for +2ºC? Is it now on to +4 ºC or +6ºC?
Just as we are discovering that the climate impact situation is much worse than we first thought9,
it turns out that the societal response to the climate problem is nowhere near strong enough to
meet even the too-weak goals of governments and international negotiations.
In 2008, the UK Government Climate Change Commission concluded that, using strategies that
are (currently) acceptable to the Government: "it is not10 now possible to ensure with high
likelihood that a temperature rise of more than +2ºC is avoided" (CCC, 2008).
In 2009 WWF released a very important report called Climate Solutions 2: Low-Carbon ReIndustrialisation. This report scoped the physical changes needed in the economy to have a
50:50 chance of avoiding +2ºC or more of warming. It then estimated the upper limits, within a
normal market economy, of the rate at which new industry sectors could be grown (consistently
over decades) and tested the rate of industrial transformation required to meet the climate target
against these limits. The report concluded that the world has only till 2014 to set the wheels in
motion and, beyond this, a "war footing" might be the only remaining option.11
In 2011, Fatih Birol, IEA Chief Economist said that the world had 5 years to change its energy
system because by 2017 the carbon budget available under a +2ºC scenario would be used up.
(Harvey, 2011) The implication being that all new investments in the energy system from then
on would need to be zero emissions.
The World Bank (2012) released the ‘Turn down the heat’ report that examined the impacts
likely to arise from a +4ºC warming, declared them unacceptable, and warned that without
further commitments [by Governments under the 2009 Copenhagen Protocol] to reduce
greenhouse gas emissions and effective action to implement those commitments, the world is
likely to warm by more than 3°C above the preindustrial climate. Even with the current
7
See the public lecture in which Kevin Trenberth explains this conclusion. (See the YouTube link is in the
references.)
8
See: http://thinkprogress.org/romm/2012/01/30/414188/super-extreme-weather-co2
9
Unacceptable impacts are already starting to be felt and future impacts are likely to be much worse earlier than
expected.
10
Emphasis added.
11
Given that a +2ºC warming is now known to be too high and that 50:50 odds of achieving even this are pretty
poor, it is fair to conclude that we are out of time to solve the climate problem using only emissions reductions and
reforms relying on normal market mechanisms.
6
mitigation commitments and pledges fully implemented, there is roughly a 20 percent
likelihood of exceeding 4°C by 2100. If they are not met, a warming of 4°C could occur as early
as the 2060s.”
The 2012 PwC Low Carbon Economy Index (PwC 2012) estimated that the required
improvement in global carbon intensity per annum to meet a +2ºC warming cap had risen to
5.1% a year, to be achieved every years from now to 2050. It argued that a critical threshold had
been passed because not once since 1950 had the world achieved that rate of decarbonisation in a
single year, but it would now have to be achieved every year from now for the next 39 years.
The report pointed out that the rate of improvement in carbon intensity actually achieved in 2011
was 0.8% per annum (compared to the needed 5.1% under their scenario). Even doubling this
historical rate of decarbonisation, would still lead to emissions consistent with +6ºC of warming
by the end of the century. To have a more than 50% chance of avoiding +2ºC would require a
six-fold improvement in the annual rate of decarbonisation.
When considering whether we should give in to failure on climate change, we need to remember
that trying to adapt to a warming of +4ºC to +6ºC will be massively expensive and in the end
will fail to provide the survival needs for most people and most species.
While, as you can see from the reports above, a number of significant organisations are
beginning to face the likely consequences of society’s inadequate action on climate change, most
people and most organisations working on climate change continue to hide from this reality and
persist in promoting inadequate goals and over-optimistic assessments of the value of currently
expected action.
This self-defeating approach is now being challenged very strongly by Kevin Anderson, Deputy
Director of the UK Tyndall Centre for Climate Change Research. Over the last couple of years
he has been actively campaigning to ‘out’ this avoidance behaviour:
“Given the grave situation we have (knowingly) got ourselves into, we need to be honest, direct
and clear as to the implications of our analysis. Only if we strip away the rhetoric and naive
technological optimism12 surrounding climate policy can we have some hope of responding
appropriately to the scale of the challenges we face. If we are not honest about the situation we
will continue to do nothing substantive. Instead we will carry on with the same ineffective
policies we have pursued for the past two decades – what I refer to as ‘cognitive dissonance’ (an
academic disguise for hypocrisy – sticking our head in the sand and, despite the science and
data, convincing ourselves everything is going to be all right).”
Source: http://whatnext.org/resources/Publications/Volume-III/Single-articles/wnv3_andersson_144.pdf
Anderson’s no-holds-barred 2012 lecture called Real clothes for the Emperor is essential
viewing for everyone working for climate action:
http://www.bris.ac.uk/cabot/events/2012/194.html
Kevin Anderson’s critique of the gap between policy and outcomes is vitally important. But the chances of
putting effective responses in place are better than he thinks is possible. The situation is somewhat more hopeful
because of four key areas where Kevin has made assumptions that are wrong or do not need to be made:
• A “war footing” mobilisation, to rebuild the economy so that it can deliver a fast restoration of a safe climate,
does not require and is not helped by his proposal for a “planned recession”. This was not the experience of
WW2. The economy boomed at that time. But what was needed was a contraction of personal discretionary
expenditure to free resources (labour and equipment) to devote to the rebuilding and war production. This will be
needed for a climate change emergency rebuilding program too.
• Not enough allowance has been made for the possibility of accelerated retirement of inappropriate assets (all the
obsolete technology of production and consumption) and their rapid replacement.
• Poor countries don’t have to continue emitting greenhouse gases longer than the rich countries if rich countries
realise that it is in their interest to help accelerate poor countries switch to a climate-compatible economy and if
poor countries with large emissions realise that it is in their own interest to take action themselves.
• The possible careful and temporary use of solar radiation management has not been factored in.
12
7
But +2ºC is not the relevant threshold anymore and we can’t live with +4ºC or +6ºC, so what
should we do?
The maximum change in the long run average global temperature during the last 10,000 years in
which civilisations emerged was +1ºC, that is plus or minus 0.5 ºC around the mean. We are
now contemplating a +4ºC or +6ºC change, knowing that scientific assessments very strongly
indicate that most people and most species will not be able to live in these temperatures. In all
likelihood wKevin has not factored in we will be facing a James Lovelockian future where a
relative handful of the rich and powerful relocate to liveable real estate at the poles, leaving the
rest to their fate.
But in the subtext of some of the reports warming us of the likelihood of +4ºC or +6ºC change
are comments that, with an industrial mobilisation of wartime intensity, we might be able to
avoid this ghastly future.
So it is still open to us to aim for a liveable climate – but knowing that it will only be possible
through nothing less than putting the economy onto an emergency footing to build a new
infrastructure.
Rethinking the climate goal – from “avoiding dangerous climate change” to “restoring a
safe climate fast”.
If we are going to have to make an unprecedented effort to rebuild out economy at emergency
speed what end-goal should we aim our efforts at? The burning embers assessment implied that
we stay under +1ºC warming (above the 1990 temperature) but our lived experience over the last
decade or so is that the current warming is too much already. So if we are going to have to take
heroic action why stay with our current mess?
But if we are to cool the planet, what should our target be?
The current climate negotiations13 are based on the idea of avoiding dangerous climate change,
where the definition of dangerous is set by what suits the more powerful countries.
If we applied this approach to the design of an air conditioning system, we would allow the
temperature to drift up or down to just the point where the fittest people in the room couldn’t
stand it getting hotter or colder and then we would leave the temperature at that point, regretting
as we did so the death from heat stress or hypothermia of the old, the infirm and the very young.
Fortunately we don’t design air conditioning systems that way. We identify a comfort or health
range of temperatures and then we design the system to keep the temperature within this range or
to return the temperature to within the comfort/health range if the temperature happens to move
outside that range.
What would a climate policy look like if we applied the air conditioning principles to the design?
Well, we want a climate that is safe for civilisation and species and is liveable for everyone (all
people and all other species). This means that the system needs to be optimised so that the
climate is not on the edge of tipping points and the global average temperature is optimal given
13
For an expansion of this discussion of the international negotiations and an alternative way of looking at climate
goal setting see: http://www.green-innovations.asn.au/RSTI/Perspective-shifting-to-help-us-rethink-our-climategoals.doc
8
the spread of people and species around the world. We also have to keep in mind that we are
dealing with a large system that is spatially diverse and that has patterned but chaotic weather.
Since people and species have had 10,000 years through the Holocene era to get used to those
conditions it seems likely that we should move the earth system back within Holocene’s one
degree variability range (see the Holocene Temperature band on page 18).14 And since one of
the key elements of the system with the largest inertia is the sea level (controlled by the melting
and accretion of ice sheets) and since the stability of the ice sheets is determined over the long
haul by the temperature of the ocean (which has a high thermal inertia) then maybe the ‘centre’
point for the Holocene temperature range is the long run average the land/sea surface
temperature that leaves the big ice sheets and thus sea levels at a safe stable point.
( http://arctic.atmos.uiuc.edu/cryosphere/IMAGES/seasonal.extent.1900-2007.jpg.)
What we are dealing with is an issue of complex system safety and there are a range of well
developed disciplines and practices for tackling such problems (Leveson, 2011).
What probability of success do we want to have with the maintenance of the whole system
within its safe zone? Since the system we are talking about is the earth that supports all people
and all species through all generations we want to have the highest possible degree of certainty.
14
Human civilisation has evolved to be highly dependent on very stable sea levels and quite stable weather. The
habitat of other species, especially on land, has been squeezed down to such relatively small fragments that most
terrestrial species are now also very dependent upon stable climate conditions. This presents a dilemma for climate
goal setting. The highly volatile climate of the last 3 million years or so (prior to the Holocene) probably played a
key role driving rapid evolution of many species, including the hominin line. Should the climate be left free to
fluctuate wildly and naturally in the temperature range of the last 3 million years (during the Pleistocene and late
Pliocene)? This might be viable if humans develop a new mode of modern civilisation that allowed huge mobility
of people across large geographical regions and if most of the land area is restored to wild habitat conditions. But
for as long as this is not the case the climate will need to be managed to stay within a very restricted Holocene
range.
9
This is like the approach we take to the design of the largest passenger aircraft where the risk of
failure is notionally “one in a million”. (With this in mind it is amazing that anyone ever took
seriously the idea that the international climate negotiations should be based on actions with a
50:50 chance of achieving the desired goal. No safety engineer in a professionally run company
would keep their job if they worked in such a way.)
Given that the elevated incidence and impact of extreme weather events indicates that the earth is
outside of the currently desirable safety zone, our task from here has three elements:
 creating an economic structure that is compatible with and generative of a safe climate;
 dealing with the legacy that creates climate non-safety; and
 ensuring a ‘safe passage’ for all people and species from the unsafe climate present to a
safe climate future.
As proximate goals for the restoration of a safe climate (and atmospheric system) with the least
negative impact on people and species, we could make it our goal to restore:
 a preindustrial temperature (as a proxy for the moment lets say that requires a drop in
temperature of +0.8ºC); and
 a preindustrial level of ocean acidity.
Restoring a safe climate fast and avoiding amplified extreme weather events
Starting with the proximate goals above we can begin to frame an action program based on a
good grasp of complex system safety and climate and earth system science.
What characteristics should the economy have if it is to be compatible with a safe climate and
safe ocean acidity? Using the method of the Natural Step15 program for avoiding
unsustainability, the aim would be to not make systematic changes that add to the problem to be
avoided. So there should be no systematic increase in greenhouse gases in the air. This means
that the average net global emissions, over time, should be zero and since the system is already
suffering badly from the accumulated systematic increase in greenhouse gas emissions this
means that the policy of getting to global net zero emissions should be implemented urgently.
No longer a ‘carbon’ budget
A corollary of the need to move with maximum speed to a zero emissions economy is that there
is no longer a carbon budget of new emissions available for allocation – to anyone.
Zero global net emissions
Many research teams have examined zero CO2 emissions scenarios and have shown that, due to
complex dynamics strongly influenced by the thermal inertia and CO2 buffering of the oceans,
dropping emissions to zero16 stops the warming trend but does not lead to a significant fall in the
temperature in less than several thousand years.17
The global temperature occurring at the time the zero emissions policy is applied is
approximately the temperature that is maintained over the long term (if zero emissions is the
only climate measure adopted). Given that we are clearly some years off the possibility of fully
applying a zero emission strategy globally, the temperature that would be maintained at the point
of full deployment of a zero emissions strategy would be a little higher than at present. If the
15
http://www.naturalstep.org/
When applied to atmospheres with greenhouse gas levels that are not yet generating very strong positive
feedbacks from the natural carbon cycle.
17
Meehl et al. (2007), Mathews & Caldeira (2008), Lowe. et al. (2009), Solomon et al. (2009), Gillett et al. (2011)
16
10
zero emissions policy was fully implemented by 2020 then the temperature at the time might
be approximately +1ºC and if completed by 2030 the temperature might be about +1.2ºC.
(from Gillett et al., 2011)
The Gillett et al. (2011) study concluded that although zero emissions translates to essentially a
stable temperature – for in excess of a thousand years – in the simulation runs different zones of
the earth react rather differently. The northern hemisphere cools significantly bringing some
relief to the Arctic, but over the 1000 years of the model run heat continues to build up in the
Southern Ocean putting stress on the stability of the West Antarctic ice sheet and the sea level
also rises over the entire time because of the heat build up in the Southern Ocean.
This hemispherically differentiated response suggest that much of the northern hemisphere
would benefit from cooling with a zero emissions policy in place, but in the absence of any
11
additional measures, continued heating in the southern hemisphere would cause conditions to
continue to deteriorate for humans, ecosystems and species in the oceans and on the land masses.
Drawdown of CO2
So while zero net emissions is essential to stop further globally averaged warming, for faster
relief from elevated temperatures, an additional strategy is needed to deal with the legacy of
elevated greenhouse gas levels.
Natural processes remove short lived greenhouse gases (eg. methane) fairly quickly but longlived greenhouse gases (such as CO2 and nitrous oxide [N2O]) are a continuing problem well
after the achievement zero global net emissions. Of the long lived greenhouse gases whose
levels are being driven up by humans, CO2 has by far the biggest influence. There are various
known technologies for drawing down atmospheric CO2. Currently the least cost18 and most
scalable options involve the growth of biomass (plant material) which is then either pyrolysed to
produce char (Woolf et al., 2010) or is combusted to create CO2. The char can then be
sequestered in soils or the CO2 can be sequestered in geological formations.
Up to the present about 340 billion tonnes of carbon, mainly in the form of CO2, has been
discharged into the atmosphere as a result of human action. About half of this has been taken up
in natural carbon sinks with the rest remains in the air. But if excess CO2 is taken out of the air,
some of the CO2 in sinks (eg. dissolved in the ocean or held in biomass) will, over time, be
returned to the atmosphere.
The drawdown process will be expensive. Although the cost of producing biochar can offset to
some extent by the sale of by product syncrude and syngas and through sale of char for soil
improvement.
There is a limit however to the speed with which the excess CO2 can be taken out of the air
because the main method of extraction is the growth of plants. With the safe passage
requirement in mind, it is essential that the growth of biomass for CO2 drawdown is not scaled
up to such an extent that the capacity to produce food and the ability to maintain natural
ecosystems and species is compromised. This scaling limit in turn limits the speed with which
the excess CO2 can be drawn down. In the end, this process of draw down could take of the
order of a hundred years or more.
There is an important interplay between the speed of the transition to a zero emissions economy
and the duration of the drawdown process. The longer it takes to achieve zero emissions the
more CO2 will be released from the economy. And in a warming world the longer the drawdown
process takes, the more CO2 there will be to draw down because of positive feedbacks releasing
carbon from natural sinks.
Relative to the millennial scale of a fully natural draw down process, the proposed human
operated drawdown of a hundred years or more is very rapid. But it is very likely that there will
still be one or more decades in the near term during which the earth remains seriously too hot.
So the two essential strategies of zero emissions and drawdown do not in themselves provide
assured safe passage to a safe climate for all of the earth’s inhabitants (humans and other
species).
An additional strategy will most likely be needed.
18
But not cheap.
12
Solar radiation management?
Throughout the history of the earth its temperature has always been the mathematical outcome of
the combined influences of:
 incoming solar radiation
 processes/substances that reflect light (higher frequency wavelengths) back to space (eg.
aerosols/dust)
 processes/substances that tend to hold energy within the earth system (greenhouse gases,
black soot, etc.).19
Natural fires, dust storms, volcanic eruptions, dimethyl sulphide originating from marine algae,
ocean salt spray have produced, at times, massive natural aerosol loads.
Ice is a powerful solar energy reflector and lighter coloured vegetation reflects more light to
space and darker coloured vegetation retains more energy.
Clouds have a huge effect on the climate and, depending on their character, can either reflect
energy to space or they can help hold energy in the earth system. Marine algae play a key role in
cloud formation, as do forests.
Unintended human influences, aside from those of greenhouse gases, have significant effects eg.
release of air pollution, changes in land use that change the colour of the land through
desertification or different coloured crops, changes to evapotranspiration by the removal or
establishment of forests, and the lighting of bushfires, etc.
At present human-released air pollution aerosols negate about half the warming effect of humanreleased greenhouse gases. If these aerosols were eliminated by effective pollution control then
global warming would double in a short time from +0.8ºC to about +1.6ºC.
So, if necessary, another strategy that could be added to the safe climate package – to contribute
to the ‘safe passage’ of the earth’s living things and to drive the earth system’s positive
feedbacks in the cooling rather than warming direction – would be to marginally increase the
reflectivity of the earth to deflect a couple of percent of the incoming solar radiation (solar
radiation management) – until the combined effect of the zero emissions and the drawdown
strategies create the conditions for the natural maintenance of a safe climate.
Various reflection/solar radiation management strategies are being investigated. The strategies
most discussed are:
 release of sulphate material (emulating some volcanic eruptions)
 cloud brightening by spraying fine particles of sea water into the cloud layer.
Single ‘colossal’ volcanic eruptions can produce cooling for a year or two of a size comparable
to the cooling needed to for a safe climate. For example in 1991 Mt Pinatubo in the Philippines
erupted, injecting massive quantities of sulphate material into the atmosphere and lowering the
global temperature by 0.3ºC to 0.5ºC for more than a year. (See references for Colossal volcanic
eruptions; Mount Pinatubo; Volcanic winter). It is argued that the global cooling effect of
volcanoes can be emulated by human injection of sulphate material into the stratosphere.
Deliberate solar radiation management measures can be scaled, at relatively modest cost, to the
point where at a gross level they can fully cancel out the warming caused by human released
greenhouse gases.
19
The natural system generates huge fluxes of greenhouse gases (water, CO2, methane, nitrous oxide, etc.).
13
But the solar radiation measures are not an exact or precise negation of the heating influences
on the atmosphere. If solar reflection methods were used, on the ground (or over the ocean) the
temperature and the behaviour of the weather could differ from what would have been expected
from a literal winding back of the impact of greenhouse gases.
So solar radiation management should not be used lightly.20 It will have undesirable side effects
– and the side effects will get worse as the application of solar radiation management is scaled
up. Solar radiation management should only be used if a science-based comparison indicates
clearly that the social and environmental impacts21 of not using solar radiation management22 are
worse than using it.
Solar radiation management should never be used as a primary or stand-alone solution to global
warming. It doesn’t solve the human-caused warming problem. Instead it just approximately
counteracts some of the warming. And it does nothing to prevent or protect against the ocean
acidification effect of elevated CO2 levels.
The problems of global warming take time to unfold, they are cumulative and there are positive
feedbacks. So the earliest possible action at full scale has the potential to eliminate the evolution
of most of the deleterious impacts of climate change (even now).
So how should the three strategies (zero emissions, drawdown and solar radiation management)
be orchestrated? The fastest possible transition to a zero emissions economy is vital to reduce
the length and cost of the drawdown effort and to cut off the further intensification of climate
impacts. And the maximum scaling23, at the earliest possible time, of the drawdown effort is
vital to reduce the duration and dosage of any solar radiation management.
Solar radiation management is a ‘last resort’ strategy from the point of view of analysing the
logic of the climate problem. But there is a really strong argument for actually applying solar
radiation management as soon as possible (once it is concluded that it is needed) to cut off most
of the damaging impacts of over-heating – to help the Arctic ice rebuild, to help the permafrost
to rebuild, to protect stressed ecosystems (coral reefs, forests, ice-related ecosystems) and to take
the heat and extreme weather stress off agriculture. Applying solar radiation management as
early as possible, and in concert with a full strength transition to a zero emission economy and a
fully-scaled drawdown program, enables the duration and dosage of solar radiation management
to be kept to the least possible extent.
Preliminary modelling of solar radiation management scenarios by Safe Climate Australia
indicate that the early application of solar radiation management can boost the ability of natural
biological sinks to draw down CO2 (by removing heat stress from forests and soils)24. This
means that less artificial CO2 drawdown is required, thus speeding up the return of the system to
a natural, self-managed safe climate regime.
Some people worry that solar radiation management using sulphate material will simply add to
the outrageous amount of air pollution that humans already put into the air. But the pollution in
the air is in the lower atmospheric layer called the troposphere. In this zone, the rain washes the
pollution out so the pollution’s average residence time is about 2 weeks. The sulphate material
proposed to be used for solar radiation management would be injected into the stratosphere
where it can stay for about 2 years. So hugely less material needs to be used in the stratosphere
20
In the same way that chemotherapy and radiation therapies for cancer treatment are not to be taken lightly as they
have significant side effects.
21
On all people and all species.
22
To approximately counteract human-caused warming.
23
Maximum compatible with the maintenance of food production and nature conservation.
24
Gary Ellem, pers. comm.. [email protected]
14
to have the same cooling effect as the amount of material that must be ‘used’ in the
troposphere.25
The three technical strategies for restoring a safe climate
So, in summary, it is still technically and logistically possible to rapidly restore a safe climate.
And by doing this we can avoiding most of the anticipated highly catastrophic impacts of climate
change.
But a safe climate can only be restored fast if the action program is based on two and most likely
three strategies:
 global zero net emissions;
 full scale drawdown of the excess CO2 in the air, and;
 most likely a time and scale limited application of solar radiation management.
A safe climate scenario
This paper centres on the goal of restoring a safe climate at emergency speed. This is not a goal
and strategy that is currently part of mainstream discussion in a clear cut way. The closest to
safe climate approach are the goals promoted by campaign group 350.org and by scientist James
Hansen.
To make it easier for scientists, policy makers, business people, journalists and campaigners to
consider the merits and drawbacks of a safe climate approach it would be helpful to develop a
well documented ‘safe climate scenario’.
A new mode of campaigning26
Given what we now know about climate impacts and the complete inadequacy of conventional
responses, there is literally no point any more in campaigning for half measures27 because these
cannot be scaled in time and nothing less than cooling the planet below its current temperature
will produce a bearable outcome.
Since most of the climate movement around the world is still geared to promoting half measures,
we need to reorientate and rebuild the movement to push for the emergency speed restoration of
a safe climate. This will involve both:
 building/strengthening organisations that are already working on the safe climate goal;
and
 helping groups that have been promoting half measures to shift to a safe climate
approach.
Groups and people working for the emergency speed restoration of a safe climate will have to
develop new methods of campaigning because we have run out of time for reform-as-usual. We
have to find ways of building sufficient support for putting the economy on an emergency
25
If the lower atmosphere was aggressively cleaned up, essentially eliminating the human-caused pollution aerosols,
it would be possible to replace the (unintended but beneficial) cooling effect of the eliminated pollution and also
fully mask the warming effect of human-originated greenhouse gases, by putting about 1/17th of the material
currently injected in the lower atmosphere as pollution into the upper atmosphere instead.
26
The issue of campaigning for the rapid restoration of a safe climate will be developed in much more detail in a
separate paper and will be referenced in an updated version of this paper when the campaign strategy paper is
completed.
27
There is still value in incremental measures that support the emergency speed restoration of a safe climate
provided the increments are designed to be compatible with the necessary transition.
15
footing and supplementing, ‘for the duration ’, market mechanisms with powerful nonmarket mechanisms.
28
Restoring a safe climate fast will not be possible unless there is strong support broadly across the
political spectrum in democracies and across the spectrum of ruling factions in non-democracies.
This is because parties and factions that are not part of the safe climate restoration effort will
more than likely imagine that they can build leverage for their grouping if they actively oppose
the safe climate effort. This tendency will only be insignificant if the safe climate effort is
understandable, supportable and seen as a vital priority from most political perspectives.
The climate problem will impact severely on people regardless of their political orientation
While the proportion of denialism, half-measurism and realism varies at present in different
political communities there is no reason to believe that a realist approach can’t build a majority
in all the numerically significant political communities. The climate movement needs to help all
political communities to build their own realist majority.
Conclusions
This paper has offered a two-part argument that:
(c) the restoration of a safe climate is still possible and as a consequence, most of the
predicted catastrophic impacts of climate change can be avoided, but
(d) this can only be achieved if we make very substantial changes to how we campaign on
climate change.
The purpose of the paper is promote debate on these propositions and to encourage people to
actively work for the rapid restoration of a safe climate.
Follow up
If you are interested in:
 safe climate science (research, writing, engagement, etc.); or
 campaigning for the rapid restoration of a safe climate
please contact:
Philip Sutton
Manager
RSTI
PO Box 27
Fairfield VIC 3078
[email protected]
(03) 9078 9746 (Australia)
Summary of the paper’s main points
This paper develops the following key points:

we are already in the early stages of the era of dangerous (and unacceptable) climate
change;
During World War 2 people talked about doing things ‘for the duration’ (ie. the duration of the war. There were
many things that people were prepared to put up with for the limited time of the war that they would not accept as a
permanent feature of life or society or the economy. This will undoubtedly be the case for the climate emergency
too.
28
16







the goal for climate policy and action needs to be changed from “preventing dangerous
climate change’ to “rapidly restoring a safe climate”.
it is still technically and logistically possible to rapidly restore a safe climate (thus
avoiding most of the anticipated highly catastrophic impacts);
a safe climate can only be restored in a timely way if the action program is based on
global zero net emissions, full drawdown of the excess CO2 in the air and most likely a
time and scale limited application of solar radiation management;
we have run out of time to restore a safe climate using the reform-as-usual approach, it
can only be done by putting the economy on an emergency footing and by
supplementing, ‘for the duration’, market mechanisms with powerful non-market
mechanisms;
there is no point in campaigning for half measures any more because these cannot be
scaled in time;
restoring a safe climate fast will not be possible unless there is strong support broadly
across the political spectrum in democracies and across the spectrum of ruling factions in
non-democracies and while achieving this broadly based support will be very difficult it
is probably not impossible;
the climate movement needs to be rebuilt around these new realities.
Key terms
+xºC warming: Generally when someone refers to a temperature increase (eg. +2ºC) they mean
above a reference point eg. preindustrial (which could mean before 1750, or more likely before
1850 or 1900). But, beware, some IPCC documents use a reference point of 1990 (when the
IPCC started work).
Climate science information
The science of global temperature
The earth’s temperature (atmospheric and sea surface temperature) is generated by the interplay
of the solar input29, the reflectivity of the atmosphere/ sea/land and processes of heat retention30.
A cooling effect can be produced by reflecting more energy to space and a heating effect can be
generated by holding more energy in the atmosphere or land or sea. The final earth temperature
is the net result of the warming and cooling processes. At the moment the human-caused
processes of warming are twice the magnitude of the human-caused cooling processes. That is,
human caused aerosol pollution, mainly in the lower atmosphere (troposphere) offsets half of the
human-caused warming processes.
There is a small flow of energy from the earth’s core.
This third factor includes the greenhouse effect. The retained energy is stored mainly in the oceans, but the
atmosphere and the land surface also store some energy.
29
30
17
(From Tenberth et al., 2009)
(From the IPCC 2007 Assessment Report 4, Working Group 1, chapter2.)
18
The history of the earth’s temperature
The earth’s land/sea surface temperature history is summarised usefully in the following three
graphs.
The source of the graphic is:
http://en.wikipedia.org/wiki/File:All_palaeotemps.png
The scientific references underpinning this graphic are found on the same webpage.
(A scaling correction was performed on the section of the graph from 542 million years ago to 100 million years.)
It’s worth noting that over the last 540 million years it appears that the temperature has only
ranged upwards by about +12ºC and downwards by about -8ºC.
The Holocene temperature band
(Slide presented at a climate change conference in April 2007 at Scripps Institute in San Diego by
Robert Corell, Global Change Director, H. John Heinz III Center for Science,)
(Known as the thin blue line diagram
During the last 10,000 years the earth’s average temperature has varied by about half a degree
around the Holocene average. Fast climate changes of this small magnitude have contributed
strongly to the decline and sometimes collapse of regional civilisations.
19
(From: Rohde et al., 2012)
(From: http://www.metoffice.gov.uk/research/monitoring/climate/surface-temperature )
20
(From: http://theenergycollective.com/davidhone/102206/inconvenient-evidence-piles )
(Frequency of occurrence (vertical axis) of local June–July–August temperature anomalies (deviations from the norm) (relative to 1951–1980
mean) for Northern Hemisphere land in units of local standard deviation (horizontal axis). According to Hansen et al. (2012), the distribution of
anomalies has shifted to the right as a consequence of global warming, meaning that unusually hot summers have become more common. This is
analogous to the rolling of a dice: cool summers now cover only half of one side of a six-sided die, white covers one side, red covers four sides,
and an extremely hot (red-brown) anomaly covers half of one side. Note that the spread of anomalies is increasing. (Hansen et al., 2012)
21
Sea levels
(Graphic source plus scientific references)
( http://en.wikipedia.org/wiki/File:Post-Glacial_Sea_Level.png )
(From: David Spratt [email protected] )
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