Techno-fixes for climate change

Last week I presented at the Australian Academy of Science on ‘techno-fixes for climate change’. This talk was part of an AAS series organised by Bryan Gaensler called “Science Fiction becomes Science Fact“.

My talk was vodcast, and goes for 38 min, followed up by about 17 min of Q&A with the audience at the Shine Dome in Canberra (Australia). In it, I discuss climate scenarios, the energy problem, advanced nuclear energy, plasma-arc torches, geo-engineering, vertical farms, desalination, synthetic fuels, and much more. I also introduce the paradigm of ecomodernism.

I hope you enjoy it.

It was also covered in a report on BuzzFeed.

An Ecomodernist Manifesto: intensify to spare nature

Originally published here on The Conversation.


Earth is now a human planet. Our species uses of a large proportion of its land-surface area for living space, agriculture and mining. We domesticate and transport a multiplicity of plant and animal species across continents. We sequester and divert freshwater.

We heavily exploit the world’s plants, animals and ecosystems, including the oceans. We are altering the atmosphere and changing the climate.

So if humanity wants to preserve “wild nature” forever, it seems reasonable to argue that we must pursue policies and actions to reverse these drivers of global change. This argument has been a cornerstone of environmental advocacy for decades.

This view motivates concern for the “population bomb” and “limits to growth”, and underpins ideas involving the transition of consumer societies to simpler, ecologically sustainable cooperatives.

In a newly released thesis, “An Ecomodernist Manifesto”, I join with 17 other leading environmental scholars to advocate for an alternative, technology-focused approach to conservation. We stress the need to embrace the decoupling of human development from environmental impacts, by seeking solutions that intensify activities such as agriculture and energy production in some areas and leave others alone.

These processes are central to economic modernisation, improved human welfare and environmental protection. Together they offer the prospect of allowing people to mitigate climate change, to spare nature and to alleviate global poverty.

Unbalanced development

Our proposal is a declaration of principles for new environmentalism. It should be considered a working document that is open to refinement. But it is also based on evidence.

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The Limits of Planetary Boundaries 2.0

Back in 2013, I led some research that critiqued the ‘Planetary Boundaries‘ concept (my refereed paper, Does the terrestrial biosphere have planetary tipping points?, appeared in Trends in Ecology & Evolution). I also blogged about this here: Worrying about global tipping points distracts from real planetary threats.

Today a new paper appeared in the journal Science, called “Planetary boundaries: Guiding human development on a changing planet“, which attempts to refine and clarify the concept. It states that four of nine planetary boundaries have been crossed, re-imagines the biodiversity boundary as one of ‘biodiversity integrity’, and introduces the concept of ‘novel entities’. A popular summary in the Washington Post can be read here. On the invitation of New York Times “Dot Earth” reporter Andy Revkin, my colleagues and I have written a short response, which I reproduce below. The full Dot Earth article can be read here.

The Limits of Planetary Boundaries
Erle Ellis, Barry Brook, Linus Blomqvist, Ruth DeFries

Steffen et al (2015) revise the “planetary boundaries framework” initially proposed in 2009 as the “safe limits” for human alteration of Earth processes(Rockstrom et al 2009). Limiting human harm to environments is a major challenge and we applaud all efforts to increase the public utility of global-change science. Yet the planetary boundaries (PB) framework – in its original form and as revised by Steffen et al – obscures rather than clarifies the environmental and sustainability challenges faced by humanity this century.

Steffen et al concede that “not all Earth system processes included in the PB have singular thresholds at the global/continental/ocean basin level.” Such processes include biosphere integrity (see Brook et al 2013), biogeochemical flows, freshwater use, and land-system change. “Nevertheless,” they continue, “it is important that boundaries be established for these processes.” Why? Where a global threshold is unknown or lacking, there is no scientifically robust way of specifying such a boundary – determining a limit along a continuum of environmental change becomes a matter of guesswork or speculation (see e.g. Bass 2009;Nordhaus et al 2012). For instance, the land-system boundary for temperate forest is set at 50% of forest cover remaining. There is no robust justification for why this boundary should not be 40%, or 70%, or some other level.

While the stated objective of the PB framework is to “guide human societies” away from a state of the Earth system that is “less hospitable to the development of human societies”, it offers little scientific evidence to support the connection between the global state of specific Earth system processes and human well-being. Instead, the Holocene environment (the most recent 10,000 years) is assumed to be ideal. Yet most species evolved before the Holocene and the contemporary ecosystems that sustain humanity are agroecosystems, urban ecosystems and other human-altered ecosystems that in themselves represent some of the most important global and local environmental changes that characterize the Anthropocene. Contrary to the authors’ claim that the Holocene is the “only state of the planet that we know for certain can support contemporary human societies,” the human-altered ecosystems of the Anthropocene represent the only state of the planet that we know for certain can support contemporary civilization.

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Critique of the proposal for 100% renewable energy electricity supply in Australia

Below is a new, detailed critique by Dr Ted Trainer of the simulation studies by Elliston, Diesendorf and MacGill on how eastern Australia might be run off 100% renewable energy. The summary:

Three recent papers by Elliston, Diesdendorf and MacGill (2012, 2013a, 2013b) elaborate on a proposal whereby it is claimed that 100% of present Australian electricity demand could be provided by renewable energy. The following notes add considerations arising from the last two papers to those discussed in my initial assessment of the first paper. My general view is that it would be technically possible to meet total Australian electricity demand from renewables but this would be very costly and probably unaffordable, mainly due to the amount of redundant plant needed to cope with intermittency. This draft analysis attempts to show why the cost conclusions EDM arrive at are probably much too low.

Ted has also updated his critique of the Zero Carbon Australia’s report on 100% renewable energy by 2020. The original BNC post is here, and the updated PDF here.

Ted notes the following:

These efforts have taken a huge amount  of time and I am still not clear and confident about my take, mainly because neither party will cooperate or correspond.  Thus I have not been able to deal with any misunderstandings etc. I have made.  Both critiques are strengthened by information I have come across since circulating previous commentaries, but they are essentially elaborations on the general line of argument taken in earlier attempts.

I find this unwillingness to engage on these criticisms by the primary authors disappointing, but typical.


Introduction

I think these three papers are valuable contributions to the considerable advance that has occurred in the discussion of the potential of renewables in the last few years. My understanding of the situation is much improved on what it was three or four years ago and I now think some of my earlier conclusions were unsatisfactory. EDM take the appropriate general approach, which is to look at how renewable technologies might be combined at each point in time to meet demand, or more accurately, to estimate how much capacity of each technology would be required, especially to get through the times when solar and wind input is minimal. EDM put forward a potentially effective way of coping with the problem of gaps in their availability via biomass derived gas for use in gas turbines. My earlier analyses did not consider this.

It is not difficult for an approach of this kind to show that electricity demand can be met, and many impressive 100% renewable energy proposals have been published. (For critical analyses of about a dozen of these see Trainer, 2014), but a great deal of redundant capacity would be needed, and the key questions are, how much, and what would it cost? My present uncertain impression is that Australia might be able to afford to do it, but if it could it would be with significant difficulty, i.e., with major impacts on lifestyles, national systems and priorities, and on society in general.

A major disappointment with the EDM analyses is that for some crucial elements no data, evidence or derivations are given and as a result the proposal can only be taken as a statement of claims. We need to be able to work through the derivations in proposals such as this to see if they are sound or what questionable assumptions might have been made etc. Consequently I have had to spend a lot of time trying to guestimate my way to an assessment of the cost conclusions and it is not possible to confident about the results.

Required capacity?

A merit of the EDM approach is to take as the target the present demand. This avoids the uncertainty introduced when attempting to estimate both future demand and the reduction in demand that conservation effort etc. might make.

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New critique of AEMO 100% renewable electricity for Australia report

Guest post by Dr Ted Trainer, University of NSW (http://ssis.arts.unsw.edu.au/tsw/).

For other critiques of the “100 Per Cent Renewables Study – Draft Modelling Outcomes” report on BNC, see here and here.

Summary: The AEMO report concludes that 100% of Australian electricity demand could be met by renewable energy sources. The claim is far from established and highly challengeable because some of the assumptions etc. are implausible and not likely to be borne out, and some crucial factors haven’t been taken into account. Intermittency has not been dealt with at all satisfactorily, embodied energy costs seem not to have been considered, and it is admitted that some major costs have not been included. It is clear that a thorough study would have arrived at an annual capital cost in the early years of construction that was several times the sum claimed. The main issue with renewables is not whether it is technically possible for them to meet total demand – it is whether the large amount of redundant plant needed to deal with intermittency could be afforded.

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This study concludes that 100% of Australian electricity demand could be met by renewable energy sources.   I think it is a valuable study, providing useful information, the kind of exploration we need, and in general its pronouncements are acceptable —  if the assumptions and inclusions/exclusions that are made clear are accepted.  However the 100% claim is far from established and highly challengeable because several of the assumptions etc. are implausible and not likely to be borne out, and some crucial factors haven’t been taken into account.  Intermittency has not be dealt with at all satisfactorily, embodied energy costs seem not to have been considered, and it is admitted that some major cost factors have not been included.   It is clear that a thorough study would have arrived at an annual capital cost in the early years of construction that was several times the sum claimed..  Following is a brief indication of some problems.

The amount of redundant, back-up plant required.

The core issue with high penetration renewables claims is to do with the amount of plant that would be needed to deal with the intermittency of wind and sun.  When both are low supply can be maintained only if there is a substantial amount of some other kind of generating capacity, or of storage capacity, that can be turned to.  Proposals attempting to provide for this end up having to assume very large quantities of back-up plant.  For instance in the Elliston, Diesendorf and MacGill proposal (2012) the multiple is 3.37.   In the Hart and Jacobson proposal for California (2011) the multiple is 4.3.  They found that in order to meet a 66 GW demand with low carbon emissions no less than 281 GW of capacity would be needed.  This would include 75 GW of gas generating capacity which would function a mere 2.6% of the time (p. 2283) and it would provide only 5% of annual demand.  This means 75 power stations would sit idle almost all the time.

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