Renewable energy: Are optimistic scenarios feasible?

A critique of The Path to a Sustainable Civilisation

Diesendorf and Taylor’s The Path to a Sustainable Civilisation (2024) is optimistic about the potential of renewables to provide a high-tech modern lifestyle. At the same time, they argue that this can only be a solution to climate change problems if we embrace some degree of degrowth. There is much about this discussion that makes sense and the detail of their plans for the use of renewables is fascinating. Nevertheless, there are some gaps in the logic of their position that are worth exploring. I will concentrate on chapter 4 on transitioning the energy system. 

As the authors announce, a key aim of the chapter is to show that ‘that the transition to an energy efficient socio-economy powered entirely by RE (renewable energy) is technically feasible and affordable’ (2023: 55). This is to be achieved by a combination of reductions in energy consumption and an energy system based on renewables. For examples, almost all residential, commercial, and industrial heating will be supplied by electric powered heat pumps. Electric vehicles will replace internal combustion vehicles, along with an increase in the proportion of public transport. Green hydrogen (or ammonia) will cover long distance flights, shipping, and some industrial uses. In other words, from the point of view of the global North consumer, it is business as usual — with a bit more public transport than they have been used to. While energy efficiency measures will in fact cost money, they will not be experienced as major alterations to current lifestyles. 

The first gap – green hydrogen

The first gap appears in this initial chapter outline. The authors acknowledge that green hydrogen and green ammonia are not yet ‘economic’. In other words, there is no economic way yet worked out to provide these services to match the price of fossil fuels. They go on to acknowledge that a quarter of current use of fossil fuels is for the services that green hydrogen and ammonia are intended to cover (2023: 57). They are optimistic that this technology will work, given time, but at present, there is no reason for this optimism. Depending on the actual cost and feasibility, it may be that things like air travel and steel making become very much more expensive, with knock on impacts on the rest of the economy — or become impossible to achieve at a cost that makes any sense. 

Their argument for degrowth

Despite their broadly optimistic picture, the authors warn that some degree of degrowth will be necessary to achieve climate goals. The authors start this discussion by pointing out that in 2000 the percentage of final energy consumption coming from fossil fuels was 80% and in 2019 it was still 80% (2023: 78). How was this possible when renewable electricity supply was also growing rapidly? The answer, they argue, is that total energy consumption was also growing. To meet climate goals, we need total energy consumption to decline substantially between now and 2050. By between 50 and 70 per cent. They join this to a more generalized support for degrowth. ‘Because energy consumption is strongly linked to economic activity, the rich countries must implement physical degrowth to a steady state economy with reduced throughput’ (2023:81). 

The gap in their argument for degrowth

There is a gap in the middle of this argument. The energy growth that maintained the proportion of fossil fuels in the total energy mix must have been in fossil fuel energy. If it had been in renewables, the proportion of fossil fuel energy in 2019 would have fallen. In other words, an effective political program of transition would have banned these increases in fossil fuel energy, wiping out their argument for degrowth.

So why has this growth in energy use been in energy sourced from fossil fuels and not in renewables? The authors note that the big growth in total energy consumption has been in the rapidly growing economies, such as China and India, that supply manufactured goods to the global North. Why have they grown their economies using fossil fuels? The most obvious answer is that coal fired power stations are still the cheapest way to supply industrial energy. But of course, this is not an answer that Diesendorf and Taylor are likely to supply. Their view is that ‘wind and solar PV are now much cheaper than electricity from fossil fuels and nuclear energy’, even when ‘short term storage’ is added to grids to deal with variable supply (2023:80).

So, what is going on here?  The authors give us various clues. In a summarizing review of the chapter, they note that ‘the only expensive technologies are batteries, which are becoming cheaper as markets grow’ and ‘green’ hydrogen. Needed for long-distance air and sea transport, road transport in remote areas, steel making (2023: 80).

So, my first suggestion is that ‘short term storage’ is insufficient to deal with the variability of electric supply from solar and wind power. To provide sufficient back up for longer periods of cloud cover and windless days, you will need ‘long term’ battery storage — more than three days (Trainer 2022). As they say, the usual battery options are expensive. An alternative is pumped hydro. Given the shortage of suitable natural sites for dams, it seems likely that large holding tanks must be constructed, also expensive. They touch on this issue in discussing the problems for Europe in moving to renewables. ‘In cold climates, such as northern Europe, seasonal storage will be needed for 100% RElec systems to supply the higher electricity demand in winter’ (2023: 63). They recommend adding to pumped hydro by using excess energy to produce hydrogen, recovering only half of the initial energy. Again, all this is expensive, undermining their optimistic claims about the costs of renewable energy. 

My second suggestion is that rapidly growing economies are also expanding their transport sectors. As the authors acknowledge, inroads of EVs into transport are as yet minimal. Though the authors have faith that the cost of EVs will come down, the industrializing countries are still buying internal combustion engine vehicles because they are cheaper. 

My final suggestion is that the increase in carbon emissions in these countries is also due to industrial processes such as steel making, where current fossil fuel options are way cheaper than promised green hydrogen alternatives. 

Bold statements and the fine print

So, what am I getting at here? There is a mismatch between the glossy pronouncements at the head of the chapter and the gaps and fine print in the rest of the chapter. The opening statements suggest that the typical global North consumer will hardly be put out by the changes they are advocating. A cheaper and more efficient energy system — providing the goods and services that they are accustomed to. Private EV transport supplemented by efficient public transport. Flights to overseas destinations. Cooking, heating and air con via renewable electric power. Urban living with foods trucked in from long distances. Industrial processes using green hydrogen. Yet when we try to understand why the market economy is not already moving in this direction, these claims start to unravel. It seems highly likely that a one hundred per cent renewable economy cannot deliver the present level of energy services, that the relative price of energy must go up massively, that all this will have an impact on the goods and services that we can realistically expect. 

Mineral resources

A final fly in the ointment is Diesendorf and Taylor’s discussion of the mineral resources needed to back up a renewable energy economy. The authors acknowledge that a shortage of ‘specific materials for RE and battery storage could exceed known reserves’ (2023: 77). The solutions are ‘disassembly, recycling, substitution and improved efficiency of manufacturing’, along with global reductions in energy consumption. In the next chapter they expand on these themes. To ensure the above, we will need caps on resource use, directed taxes, and regulations on manufacturing.

In conversation, Diesendorf acknowledges the relevance of the findings of Simon Michaux on these issues. So let us go to these now. Michaux is a geologist, with special interest in minerals and mining. His report to the Geological Survey of Finland outlines the problems with optimistic scenarios based on replacing fossil fuels with renewables. ‘Global reserves are not large enough to supply enough metals to build the renewable non-fossil fuels industrial system or satisfy long term demand in the current system’ (Michaux 2021: 2). To transition to a renewable economy, we have to create new machinery using minerals sourced via mining. There is no option to recycle minerals from machinery that we do not yet have.  Yet there are insufficient global reserves of minerals such as lithium, nickel and cobalt, even copper. For example, with copper, a metal central to the electrification project:

In 2019, global consumption of copper metal was 24.5 million tonnes and global copper reserves was reported at 870 million tonnes (USGS mineral statistics). Using a straight and crude calculation, this means that current reserves represent 35.5 years of supply at 2019 mining and recycling rates. Copper demand is projected to increase to approximately 100 million tonnes per annum by the year 2100 (Michaux 2021: 9).

Another paper authored by Michaux and others, includes a table that compares the mineral requirements for a fleet of EVs to match current internal combustion engines — with the known reserves of these minerals. Known reserves are between half and a quarter the size of requirements for zinc, lithium and graphite. They note that similar results apply if we compare known reserves of minerals to requirements for wind turbines and solar panels (Michaux et al 2021: 81). Michaux is sceptical about the prospects for recycling. He points out that we have yet to construct the first generation of this machinery – so we will need mining to get those minerals in the first place. For future iterations of this technology, he points out that the efficacy and costs of recycling depend on the mineral in question. He does not expect much change from current rates of recycling – between one and fifty per cent (Michaux 2021: 11).

I read these analyses as casting serious doubt on Diesendorf and Taylor’s picture of the transition. What is problematic is their picture of the global North consumer of the future, continuing with air travel, air con, heat pump warming, private cars and the like. This seems very unlikely. Limited mineral resources would mean that a program of global electrification would massively increase the price of every aspect of this scenario — as businesses competed for access to inadequate mineral resources. Ranging from the cost of electrical energy to the cost of private cars. At most, an elite of global North consumers would maintain the lifestyles now common for even the working class of the global North. More likely the political impact of this betrayal would see the class accommodations of the present evaporate.

Horse and buggy degrowth 

So where might we end up in the best of all possible worlds? Diesendorf and Taylor reserve their scorn for those who think we might be forced to ‘heat our homes with firewood’ and use ‘horse and buggy for transport’ (2023: 87). Yet, strangely, they paint a picture of the future for the global South that looks a lot like that. A ‘more accessible’ model of a sustainable society for the ‘low-income majority’ could look like this, they say (2023: 64). A single solar PV panel with a small battery might power a radio, lights, a mobile phone. Cooking would be on wood fired stoves. There would be no grid power for this majority of the earth’s population. I will assume these majority world residents do not have EV cars but travel by bicycle or donkey cart in their rural villages — with occasional use of a national rail service! To state the obvious, this program for the global South is identical to the ‘horse and buggy’ degrowth promoted by writers such as Ted Trainer (2010). 


I have called this a discussion of Diesendorf and Taylor ‘in their own words’. The call for up to seventy per cent degrowth for the global North strikes a jarring note in an upbeat paean of praise for a renewable ‘civilisation’. This target for degrowth does not tally with their bold statement promises to affluent consumers. Perhaps, their ambitious degrowth target is tacit recognition of the gaps in their argument. The fine print keeps getting away from them, whether it is the cold winters of Europe, the unknown costs of green hydrogen or the shortage of minerals required for the transition. I wonder whether their bold statement promotion of a glossy future reflects a political strategy. Look, guys, it won’t be that bad, you can keep on doing the things you are doing now — after a shortish period of heavy government intervention. 

The Melbourne branch of Degrowth Network Australia recently hosted a Zoom discussion of an article by Bill Rees on overshoot. Among other claims, Rees argues that a program of replacing fossil fuels with renewables is unworkable. More likely, we will end up with a low-tech economy. Mark Diesendorf and his colleague, Manfred Lenzen, joined the Zoom to promote their view of the transition. And to attack those who thought we were going to need a more radical degrowth. A key moment was Lenzen replying to several speakers from the Melbourne Degrowth group. These de-growthers were concerned about the social costs of extractivism, the new mining required for this transition. What Lenzen said was, well yes, these are problems, but nowhere near as bad as what might happen with climate change if we keep on with fossil fuels. In other words, those in the Degrowth movement — who aim at a more drastic degrowth — are undermining their efforts. They see their task as being to reassure the mainstream majority that a renewable transition can be achieved — without major sacrifice. From their perspective, the critique coming from writers like Rees and from this noisy minority is just fodder for those who want to hang on to fossil fuels. I suspect this is why ‘horse and buggy’ de-growthers receive such a bucketing from Diesendorf and those who follow this logic. 

One response to this situation is to wish this Green Transition perspective well. Let them get the political support to try this out. The problems with their program will become clear enough in practice. My only concern is this. You can perhaps persuade a rich global North electorate to support this vision of a Green Transition through a few electoral cycles. But as the costs become more and more apparent, this support drains away, leaving a bad taste of betrayal. You told us that this would be easy, but everything is costing more, we cannot afford an EV, an induction cooktop or a heat pump to replace our gas heating. All our bills are going up. Joined to this, the usual problems of the neoliberal economy for global North electorates. Housing prices, inflation, insecure employment. It seems highly likely that this reaction is behind the slump in support for the Greens in much of Europe, with a similar downturn in support for climate action in Australian polling (Stevis-Gridneff 2024; Crowe 2024; Hamilton & Wilkenfeld 2024). 

My own view of a more adequate political response is one that emphasizes the need for heroic sacrifice now for the future of the human species — and other living beings. This program cannot readily be co-opted. We should also be promoting an end to capitalism and the market. We can argue that a non-monetary ‘gift economy’ is the only system that would in fact deliver security and creative control — along with sustainability (Nelson 2022; Leahy 2024). Our current task is spreading the message of degrowth, while helping to build local alternatives that meet current needs.

We shall fight them on the bike paths and in the community gardens. We shall never surrender!


Crowe, David 2024, The majority of voters back Labor’s 2030 climate target – but only just, The Age, June 18.

Diesendorf, Mark and Rod Taylor 2023, The Path to a Sustainable Civilisation, Palgrave Macmillan, Singapore.

Hamilton, Clive and 2024, Living Hot: Surviving and Thriving on a Heating Planet, Hardie Grant, Melbourne.

Leahy, Terry 2024, Talking Turkey: The Gift Economy and System Change, Researchgate,

Michaux, Simon P. 2021, The Mining of Minerals and the Limits to Growth, 

Report number: 16/2021, Geological Survey of Finland, Helskinki.

Michaux, Simon P., Tere Vadén,  J.M. Korhonen and Jussi T. Eronen 2021, Assessment of the scope of tasks to completely phase out fossil fuels in Finland, Report 18/2022, Geological Survey of Finland, Helskinki.

Nelson, Anitra 2022, Beyond Money: A Post-Capitalist Strategy, Pluto Press, London.

Rees, William E. 2023, The Human Ecology of Overshoot: Why a Major ‘Population Correction’ Is Inevitable, World, 4, 509–527.

Stevis-Gridneff, Matina 2024, Europe, long considered a climate leader, has dumped Greens at the polls, The Age, June 16.

Trainer, Ted 2010, The Transition to a Sustainable and Just World, Envirobooks, Canterbury, NSW.

Trainer, Ted 2022, Can Australia Run on Renewable Energy: Unsettled Issues and Implications, Biophysical Economics and Sustainability, 7:10.

Terry Leahy - Permaculture

Terry Leahy is now living in Melbourne, having worked in sociology at UNSW and University of Newcastle between 1973 and 2017. Key interests have been food security for rural Africa, the global environmental crisis, and the philosophy of the social sciences. He promotes the gift economy as the long-term solution to current problems. His most recent book is The Politics of Permaculture

Image Credit. Cristales en rama by Gonzalo G. Useta (2015) CC BY-NC-ND 2.0