This is a brief summary of the report Dangerous climate change: Myth & Reality, which considers recent scientific literature to explore seven myths of the predominant climate policy making paradigm.

Amongst advocates for action on climate warming, there is a presumption of agreement on the core science that underlies policy making, even though differences exist in campaign strategy. But the boundaries between science and politics have become blurred in framing both the problem and the solutions.

On the science side, the challenge is of a fast-developing discipline in a rapidly changing physical world. There is a concerted and unwarranted global attack on climate scientists and, in Australia, intimidation and fear of job loss generated by the Abbott government’s hostility to science and cuts in climate research funding. As well, there are always uncertainties and unknowns in science, and difficulties in communicating complex understandings in a non-technical manner. Together these factors can produce over-cautiousness in public presentation and scientific reticence.

On the politics side, often insufficient attention is paid to the breadth and depth of published research, and there is a tendency to prioritise perceived political relevance over uncomfortable scientific evidence.

Most climate advocacy organisations allocate few resources to critically interrogating the climate research as part of strategy and policy development, and generally fall into a middle-of-the-road advocacy consensus which downplays the warnings from the more forthright scientists whose expert elicitations – on such topics as the stability of ice sheets and sea ice to future sea-level rises – have generally proven more robust than those of their more reticent colleagues.

Much of the recent international policy discourse has focused on "what percentage reductions by when and by whom" in emissions would stop warming passing 2°C. In Australia, is it 5% by 2020, or 19%, or a lot more? Till 2030 or 2050?

An observer of this discourse would not think that 2°C is other than a reasonable target, and that we have plenty of carbon emissions left for a few decades more. They would certainly not understand that such propositions are dangerous myths. Here's why.

Myth 1: Climate change is not yet dangerous

In 2008 John Holdren, who was then senior advisor to President Barack Obama on science and technology issues, told the Eighth Annual John H. Chafee Memorial Lecture on Science and the Environment: ". . . the (climate) disruption and its impacts are now growing much more rapidly than almost anybody expected even a few years ago. The result of that, in my view, is that the world is already experiencing ‘dangerous anthropogenic interference in the climate system’" (Holdren, 2008).

“Dangerous” climate change is broadly characterised by the Intergovernmental Panel on Climate Change (IPCC) in the “burning embers” diagram as including five reasons for concern: risk to unique and threatened systems; risk of extreme weather events; distribution of impacts; aggregate (total economic and ecological) impacts; and risk of large-scale discontinuities (that is, abrupt transitions or tipping points).

From this perspective, tipping points have already been passed, at less than 1°C of warming, for example:

• The loss of the Amundsen Sea West Antarctic glaciers, and 1–4 metres of sea level rise (Rignot, Mouginot et al., 2014; Joughin, Smith et al., 2014). Dr Malte Meinshausen, advisor to the German government and one of the architects of the IPCC's Representative Concentration Pathways, calls the evidence published this year of "unstoppable" (Rignot, 2014) deglaciation in West Antarctica "a game changer", and a "tipping point that none of us thought would pass so quickly", noting now we are "committed already to a change in coastlines that is unprecedented for us humans" (Breakthrough, 2014).
• The loss of Arctic sea-ice in summer (Duarte, Lenton et al., 2012; Maslowski, Kinney et al., 2012), which will hasten regional warming, the mobilization of frozen carbon stores, and the deglaciation of Greenland.
• Numerous ecosystems, which are already severely degraded or in the process of being lost, including the Arctic (Wolf, 2010). In the Arctic, the rate of climate change is now faster than ecosystems can adapt to naturally, and the fate of many Arctic marine ecosystems is clearly connected to that of the sea ice (Duarte, Lenton et al., 2012). In May 2008, Dr Neil Hamilton, who was then director of Arctic programmes for WWF, told a stunned audience (of which I was a member) at the Academy of Science in Canberra that WWF was not trying to preserve the Arctic ecosystem because “it was no longer possible to do so”.

The current level of greenhouse gases is around 400 ppm carbon dioxide (parts per million CO2), and 470ppm carbon dioxide equivalent (CO2e) when other greenhouse gases including methane and nitrous oxide are included. The last time CO2 levels were as high as they are today, humans didn't exist, and "CO2 values associated with major climate transitions of the past 20 millions years are similar to modern levels" (Tripati, Roberts et al., 2009).

In other words, big changes (“transitions”) in significant climate system elements such as ice sheets, sea levels and carbon stores are likely to occur for the current level of CO2.

Myth 2: 2°C is an appropriate focus for policy making

The evidence above indicates that dangerous tipping points have already been passed at the current level of climate warming of 0.8°C, so 2°C of warming is clearly not an appropriate focus for policy making. 2°C is a very unsafe target in any framing of risk. It is more appropriately considered as the boundary between dangerous and very dangerous climate change (Anderson and Bows, 2010). In Australia, 2°C would likely mean, amongst many impacts, the loss of the Great Barrier Reef, the salination of Kakadu, and the loss of the north Queensland tropical rainforests.

This is consistent with a framework of "planetary boundaries" published in 2009, which “define the safe operating space for humanity with respect to the Earth system and are associated with the planet’s biophysical subsystems or processes” (Rockstrom, Steffen et al., 2009). It proposes a boundary of less than 350 ppm CO2e, compared to the current level of more than 470 ppm CO2e. Research also finds that:

• 1C° of warming over the pre-industrial baseline — which we are now approaching — is hotter than the Holocene maximum (the period of human civilisation up to 1900) (Marcott, Shakun et al., 2013; Hansen, Kharecha et al., 2013).
• For 2°C of warming, the sea-level rise will likely eventually be measured in the tens of metres (Rohling, Grant et al., 2009).
• Hansen and Sato (2012), using paleoclimate data rather than models of recent and expected climate change, warn that “goals of limiting human made warming to 2°C and CO2 to 450 ppm are prescriptions for disaster” because significant tipping points – where significant elements of the climate system move from one discrete state to another – will be crossed. As detailed in the next section, numerous tipping points are likely well before 2°C.

Myth 3: Big tipping points are unlikely before 2°C

Tipping points, often an expression of non-linear events, are difficult to project. But if it is sometimes hard to see tipping points coming, it is also too late to be wise after the fact. Estimated tipping points around or below ~1.5°C include:

• West Antarctic Ice Sheet: Current conditions affecting the West Antarctic Ice Sheet are sufficient to drive between 1.2 and 4 metres of sea rise, and these glaciers are now in "unstoppable" meltdown at global average warming of just 0.8oC (NASA, 2014A; Rignot, Mouginot et al., 2014; Joughin, Smith et al., 2014).
• Loss of summer Arctic sea-ice: Livinia and Lenton (2013), UWA (2012), Serreze (quoted by Romm, 2012), Wadhams (2012, and quoted by Vidal, 2012), Maslowski, Kinney et al. (2012) and Laxton (quoted by McKie, 2012). Duarte, Lenton et al. (2012) find that: “Warming of the Arctic region is proceeding at three times the global average, and a new ‘Arctic rapid change’ climate pattern has been observed in the past decade.” Maslowski, Kinney et al. (2012) note that: “a warming Arctic climate appears to affect the rate of melt of the Greenland ice sheet, Northern Hemisphere permafrost sea-level rise, and global climate change”.
• Greenland Ice Sheet (GIS): Estimated tipping point for GIS is +1.6oC with an uncertainty range of +0.8 to +3.2oC (Robinson, Calov et al., 2012). A recent study finds that deep canyons will contribute to more rapid GIS deglaciation (NASA, 2014B; Morlighem, Rignot et al., 2014). Contrary to previous studies, that estimated it would take centuries to millennia for new climates to increase the temperature deep within ice sheets such as GIS, the influence of melt water means warming can occur within decades and produce rapid accelerations (Phillips, Rajaram et al., 2013; University of Colorado Boulder, 2013).
• Coral reefs: “Preserving more than 10 per cent of coral reefs worldwide would require limiting warming to below +1.5°C (atmosphere–ocean general circulation models (AOGCMs) range: 1.3–1.8°C) relative to pre-industrial levels” (Frieler, Meinshausen et al., 2013). At 10 per cent, the reefs would be remnant, and the ecosystems as we know them today would be a historical footnote. Data suggests the area of reef systems has already been reduced by half around the world.
• Permafrost: In February 2013, scientists using radiometric dating techniques on Russian cave formations to measure melting rates warned that a 1.5°C global rise in temperature compared to pre-industrial was enough to start a general permafrost melt.

In summary, there is a very high risk that further significant tipping points will be passed before warming reaches 2°C. Some of these are irreversible on time scales of centuries to a millenia.

Myth 4: We should mitigate for 2°C, but plan to adapt to 4°C

The failure of international climate negotiations and insufficient national efforts have led many negotiators and commentators to conclude that warming will not be held to 2°C and much higher warming is likely. This has resulted in a policy approach of still trying to reduce emissions (mitigate) for 2°C, whilst also planning to adapt to 4°C of warming. World Bank (2012) and Price Waterhouse Coopers (2012) reports complement a range of research that suggests the world is presently heading for 4°C or more of warming this century.

Global average warming of 4°C means around 6°C of warming over land, and perhaps 7–8°C at the extremes. IEA Chief Economist Fatih Birol says that emission trends are “perfectly in line with a temperature increase of 6°C, which would have devastating consequences for the planet” (Rose, 2012).

Professor Kevin Anderson says, the notion that we can reasonably adapt to 4°C is ill-founded because "a 4° future is incompatible with an organized global community is likely to be beyond adaptation, is devastating to the majority of ecosystems and has a high probability of not being stable".

Myth 5: We have a substantial carbon budget left for 2°C

The carbon budget has come to public prominence in recent years, including in the IPCC’s Fifth Assessment Report in 2013, as being the difference between the total allowable greenhouse gas emissions for 2°C of warming, and the amount already emitted or spent. But this is not as simple as it seems, because 2°C means different things to different people.

• If some reasonably optimistic assumptions are made about deforestation and food-related emissions (halving per unit of production) for the rest of the century, then most emission reduction scenarios are incompatible with holding warming to 2°C, even with a high 50% probability of exceeding the target, and there is no budget left for fossil fuel emissions (Anderson and Bows, 2008).
• If we make some optimistic assumptions about how soon emissions peak and decline in the developing world, there is no carbon budget available for developed nations (Anderson and Bows, 2011)
• Accounting for the possible release of methane from melting permafrost and ocean sediment implies a substantially lower budget, but this was not done (IPCC 2013).

The idea of a carbon budget and “allowable” emissions is dangerous. According to climate scientist Ken Caldeira, "There are no such things as an 'allowable carbon dioxide (CO2) emissions'. There are only 'damaging CO2 emissions' or 'dangerous CO2 emissions'. Every CO2 emission causes additional damage and creates additional risk."

Myth 6: Long-term feedbacks are not materially relevant for carbon budgeting

Some elements of the climate system respond quickly to temperature change, including the amount of water vapour in the air and hence level of cloud cover, sea-level changes due to ocean temperature change, and the extent of sea-ice that floats on the ocean in the polar regions. These changes amplify (increase) the temperature change and are known as short-term or “fast” feedbacks.

There are also long-term or slow feedbacks which generally take much longer (centuries to thousands of years) to occur. These include changes in large, polar, land-based ice sheets, changes in the carbon cycle (changed efficiency of carbon sinks such as permafrost and methane clathrate stores, as well as biosphere stores such as peat lands and forests), and changes in vegetation coverage and reflectivity (albedo). The IPCC’s 2013 assessment did not account for long-term feedbacks.

Prof. Will Steffen (2013) notes that, "This budget may, in fact, be rather generous. Accounting for non-CO2 greenhouse gases, including the possible release of methane from melting permafrost and ocean sediments, or increasing the probability of meeting the 2°C target all imply a substantially lower carbon budget". The question is whether these feedbacks are materially relevant for this century's time-scale, and the evidence is in the affirmative.

Myth 7: There is time for an orderly, non-disruptive reduction in emissions within the current political-economic paradigm

Advocates for climate change action often emphasise the positive economic consequences, such as a boom in “green” jobs, the clean energy industrial revolution, or the great investment opportunities. But there is another economic component to the discourse. It is the view that actions should not be undertaken that would be economically disruptive, and therefore the range of actions to be considered should only be those which do not challenge overall economic growth.

The unfortunate consequence of this framing is that actions that are necessary are not advocated, as was demonstrated in their respective reports to the UK and Australian governments by Sir Nicholas Stern and Prof. Ross Garnaut.

Stern (2006) said keeping the rise to 2°C was "already nearly out of reach" because it meant emissions "peaking in the next five years or so and dropping fast", which he judged to be neither politically likely nor economically desirable. He said that annual emission reductions of more than one per cent a year “have historically been associated only with economic recession or upheaval”, and that it would be “very difficult and costly to aim to stabilise at 450ppm CO2e” (viewed as a 2°C target).

So he nodded towards a higher target where “the annual costs of achieving stabilisation between 500 and 550ppm CO2e are around 1% of global GDP” because “stabilisation of greenhouse gas concentration in the atmosphere is feasible and consistent with continued growth”.

Likewise, Garnaut was drawn to the politically pragmatic in his work. Whilst it was clear by the end of 2007 that 450 ppm was far from a safe or reasonable target, the Review did not heed strong calls from advocates to model and consider a safer 350 ppm scenario and, like Stern, it stuck to the 450 and 550 ppm targets. And whilst describing the action necessary for Australia to play a reasonable part in holding to 450ppm, Garnaut then suggested that as interim measure, pending global agreement, that Australia should act only for the 550ppm target.

Prof. Kevin Anderson notes that: “Reductions in emissions greater than 3-4 per cent per annum are incompatible with a growing economy (or so we’re repeatedly advised). From Stern and the UK’s Committee on Climate Change through to virtually every 2°C emission scenario developed by ‘Integrated Assessment Modellers’, reductions in absolute emissions greater than three to four per cent year on year are judged incompatible with a growing economy . . . we have found no examples of economists suggesting that prolonged emission-reductions above three to four per cent per annum are economically sustainable” (Anderson, 2013).

Whether fast rates of de-carbonisation are incompatible with a growing economy is not established, because they may be possible in a highly-regulated economy, even if not in the deregulated economies about which Stern and Garnaut were writing. But the practical consequence is that few advocates want to push high de-carbonisation rates because of the perception of negative economic consequences.

For industrialised nations with high per capita emissions, adhering to the 2°C target (even with high risks of failure) requires emissions reductions of round ten per cent a year. See Figure 4. But very few participants in climate policy-making are prepared to even whisper about such a scale of action, less they be considered economic vandals.

Conclusion

• At just 0.8°C of warming and with temperatures just above the Holocene zone, climate change is already dangerous with tipping points passed for significant earth system elements, including West Antarctic glaciers and summer Arctic sea-ice. The last time greenhouse gases were this high, temperatures were 3+°C degrees higher, and sea levels 25-40 metres higher.
• 2°C of warming is the boundary between dangerous and very dangerous climate change, and the non-dangerous (safe) zone is well under 1°C and in the Holocene range, yet the present level of greenhouse gases is sufficient to produce more than 2°C of warming.
• We have already gone too high with greenhouse emissions, and practically speaking there is no carbon budget available for burning more fossil fuels for the 2°C target, and no carbon budget available if catastrophic risk management methods (low rates of failure) are applied.
• Australia is just 0.3% of the world's population but counts for 1.5% of emissions, five times the global average, and one of the world's highest per capita emitters. Taking the IPCC's too optimistic carbon budget at face value, and allowing equal global per capita emissions, Australia's carbon budget for 2°C runs out in six years.
• To minimise climate change damage and avoid reaching 2°C — by which time many significant tipping points and carbon cycle feedbacks will likely have been triggered — it is necessary for a global emergency response which aims to de-carbonise as fast as humanly possible, plus build large carbon drawdown capacity, to try and keep warming below 1.5°C and then return to the Holocene zone.

Many participants in global discussions and debates say such a scale of action is not possible in a non-disruptive manner within the current political-economic frame. If this is the case, we face a choice of challenging this frame, or accepting that we must fail in our goal.

Whether or not there is yet the political power or support for actions consistent with the science, it is important that they be articulated so that understanding and support for them can grow.

• Read David's entire paper, Dangerous climate warming: Myth & reality / Réchauffement climatique dangereux: Mythes et réalité (French version)
• Listen to David's lecture at the Breakthrough Climate Restoration Forum, October 2014
• Keep up to date with the latest climate-policy news and global activism at Climate Code Red