Fifth and last in a series
The research evidence and expert elicitations demonstrate that climate conditions are “dangerous” now – according to the generally accepted “safe boundary”, “five concerns” and “tipping point” metrics.
- The 350 ppm “safe boundary” for atmospheric CO2 has already been exceeded by 50 ppm.
- In 2007, at around +0.76ºC warming (equivalent to ~335 ppm CO2 at equilibrium), Arctic sea-ice passed its tipping point. The Greenland Ice Sheet may not be far behind, as the Arctic moves to sea-ice-free conditions in summer, triggering further tipping elements.
- Around +1.5ºC warming may be the tipping point for the Greenland Ice Sheet and for the large-scale release of Arctic carbon permafrost stores. At +1.5ºC, coral reefs would be reduced to remnant systems.
- The paleo-climate record shows that the current level of atmospheric CO2 at 400 ppm is enough to produce sea-level rises of 20–40 metres; is around the tipping point for large-scale release of Arctic carbon permafrost; and is sufficient to trigger powerful amplifying polar feedbacks.
A safe climate would not exceed the Holocene maximum. The notion that +1.5ºC is a safe target is contradicted by the evidence, and even +1ºC degree is not safe given what we now know about the Arctic.
Emission reduction challenges
The dominant climate policy frame I have observed goes along these lines: “Let’s hope it’s not as bad as you say… Even if you are right about the Arctic… holding the system to +2ºC will be very difficult… and a huge political and economic challenge… but it’s the best we can hope for… and while it might be dangerous…that’s a hell of a lot better than +3 or 4ºC … which would be catastrophic.”
The discussion on “doing the maths” for the carbon budget is about the total emissions available without exceeding 2ºC of warming.
This task is very much more challenging than policy-makers accept, as Anderson and Bows demonstrate in their 2008 and 2011 papers on emission reduction scenarios. They make some optimistic assumptions about de-afforestation and food-related emissions for the rest of the century, and then ask what emission reduction scenarios would be compatible with holding warming to +2ºC, and find that:
- Of the 18 scenarios tested, ten cannot be reconciled with ~450 ppm CO2e.
- If emissions to do not peak till 2025, no scenarios are available.
- 450 ppm CO2e requires energy emissions to be stabilised by 2015, then decline annually by 6-8 per cent for 2020–2040, with full de-carbonisation by 2050.
- A five per cent annual reduction in emissions from a 2020 peak (and a 6–7 per cent annual reduction in energy and process emissions) correlates near 550 ppm CO2e, or +3ºC of warming. If the emissions reduction after a 2020 peak is three per cent, this correlates near 650 ppm CO2e, or +4ºC of warming.
- And looking at equity issues: if non-Annex 1 (developing) nation emissions grow three per cent a year to 2020 and then peak in 2025, there is no carbon budget available for Annex 1 (developed nations) after 2015, for the IPCC’s low-emissions carbon budget.
Two degrees, or four?
In June 2013, a German research institute which advises Angela Merkel’s government concluded that “policy makers must come up with a new global target to cap temperature gains because the current goal… limiting the increase in temperature to 2°C since industrialization is unrealistic”. It recommended that “world leaders either allow the 2°C goal to become a benchmark that can be temporarily overshot, accept a higher target, or give up on such an objective altogether”.
International Energy Agency Chief Economist Fatih Birol calls the 2°C goal “a nice Utopia”: “It is becoming extremely challenging to remain below 2°C. The prospect is getting bleaker. That is what the numbers say.”
The prevailing climate policy-making framework now poses a choice between a “dangerous but liveable” 2ºC of warming and the “catastrophe” of 4ºC or more, as reflected in the statement by John Holdren that opens this paper.
The World Bank and PriceWaterhouseCoopers have recently published reports which complement a wide range of scientific research which concludes that the world is presently heading for 4ºC or more of warming this century, and as soon as 2060. Reuters correspondent Michael Rose (2012) quotes IEA Chief Economist, Fatih Birol as saying that emission trends are “perfectly in line with a temperature increase of 6°C, which would have devastating consequences for the planet”.
Anderson says there is a widespread view amongst scientists that “a 4°C future is incompatible with an organised global community, is likely to be beyond ‘adaptation’, is devastating to the majority of eco-systems and has a high probability of not being stable”.
Yet the 2ºC goal is not an option either, because, with climate and carbon cycle positive feedbacks in full swing, it is less a stable destination than a signpost on a highway to a much hotter place. The real choice now is to try and keep the planet under a series of big tipping points by getting it back to a Holocene-like state, or accept that a 3-6ºC “catastrophe” is at hand.
Policy-makers officially focus on the 2ºC goal, without admitting the ambition entailed:
…while the rhetoric of policy is to reduce emissions in line with avoiding dangerous climate change, most policy advice is to accept a high probability of extremely dangerous climate change rather than propose radical and immediate emission reductions. (Anderson and Bows)As Anderson and Bows show, if global emissions don’t peak till 2020, then the carbon budget for the developed world is… zero. Even the 2ºC target requires actions that are completely outside the current climate policy-making framework, and therefore considered impossible.
In “A new paradigm for climate change”, Anderson and Bows call for academic rigour in elaborating the scientific and economic choices:
… academics may again have contributed to a misguided belief that commitments to avoid warming of 2°C can still be realized with incremental adjustments to economic incentives… as the remaining cumulative budget is consumed, so any contextual interpretation of the science demonstrates that the threshold of 2°C is no longer viable, at least within orthodox political and economic constraints…Anderson is the Deputy Director of the Tyndall Centre for Climate Change Research, which in late 2013 is hosting a Radical Emission Reduction Conference, whose purpose is described as:
At the same time as climate change analyses are being subverted to reconcile them with the orthodoxy of economic growth, neoclassical economics has evidently failed to keep even its own house in order. This failure is not peripheral. It is prolonged, deep-rooted and disregards national boundaries, raising profound issues about the structures, values and framing of contemporary society… This catastrophic and ongoing failure of market economics and the laissez-faire rhetoric accompanying it (unfettered choice, deregulation and so on) could provide an opportunity to think differently about climate change…
It is in this rapidly evolving context that the science underpinning climate change is being conducted and its findings communicated. This is an opportunity that should and must be grasped. Liberate the science from the economics, finance and astrology, stand by the conclusions however uncomfortable. But this is still not enough. In an increasingly interconnected world where the whole — the system — is often far removed from the sum of its parts, we need to be less afraid of making academic judgements. Not unsubstantiated opinions and prejudice, but applying a mix of academic rigour, courage and humility to bring new and interdisciplinary insights into the emerging era. Leave the market economists to fight among themselves over the right price of carbon — let them relive their groundhog day if they wish. The world is moving on and we need to have the audacity to think differently and conceive of alternative futures.
Today, in 2013, we face an unavoidably radical future. We either continue with rising emissions and reap the radical repercussions of severe climate change, or we acknowledge that we have a choice and pursue radical emission reductions: No longer is there a non-radical option. Moreover, low-carbon supply technologies cannot deliver the necessary rate of emission reductions – they need to be complemented with rapid, deep and early reductions in energy consumption – the rationale for this conference.To repeat: “…we face an unavoidably radical future… no longer is there a non-radical option.” Can this phrase help liberate us from the prevailing climate policy-making paradigm, from which no further hope can be wrung?
In 2008, in a statement for the book Climate Code Red I authored with Philip Sutton, James Hansen wrote:
We must begin to move rapidly to the post-fossil fuel clean energy system. Moreover, we must remove some carbon that has collected in the atmosphere since the Industrial Revolution. This is the story that Climate Code Red tells with conviction. It is a compelling case for recognising, as the UN secretary-general has said, that we face a climate emergency.And what would a radical, emergency-action option look like, and why it is absolutely necessary as the last, best hope we have? We described some of its features in Climate Code Red, as has Paul Gilding in his 2011 book, The Great Disruption. And this year, Delina and Diesendorf published research from the University of NSW on the question: “Is wartime mobilisation a suitable policy model for rapid national climate mitigation?”
In addition to stopping fossil fuel emissions, very large-scale carbon dioxide removal (CDR) would be a critical task, to reduce the level of atmospheric greenhouse. Can CDR be achieved at the size and scale required to help get us back to safety? A recent and very good survey of CDR options and technologies, their costs, effectiveness and environmental consequences has been just published by Caldeira, Bala et al. As well, it now seems clear that if we are to prevent the world tripping past a number of critical tipping points, some forms of geo-engineering such as solar radiation management (SRM) will be necessary in the short term. This would be an adjunct to a zero-emissions program and CDR, especially as the “global dimming” effect of aerosols is reduced as emissions fall. Here, too, Caldeira, Bala et al. provide a useful survey, including the pitfalls, the challenging governance issues and the many “known unknowns”.
All of this may seem like a lot of “ifs” and “buts” and “maybes”. We are now in a world of making the least-worst choices. There is no simple answer, and we do not yet know all the questions in detail, let alone all of the answers. Nobody ever does at the beginning of an emergency response. That’s what makes it an emergency. But we do now know, with clear evidence that climate change is already “dangerous”, that we are heading towards a “catastrophe”, that we are in an emergency and, yes, we do face “…an unavoidably radical future”. And we do know from past experience that once societies are in emergency mode, they are capable of facing up to and solving seemingly impossible problems.