Taking Stock

22 December 2022
Taking Stock - Featured image

Taking the Global Methane Pledge will harm Australia’s economy and have no impact on climate change, argues Professor Emeritus of Government Aynsley Kellow.

I recently described climate policy by drawing on Scottish author Charles Mackay’s 1841 essay Extraordinary Popular Delusions and the Madness of Crowds, the title of which should give you the idea. The delusion seems to continue after the May 2022 election in Australia, with no awareness of mistakes such as Germany’s Energiewende (energy turnaround) yet to be seen in Canberra.

Prime Minister Albanese keeps assuring us that renewables are the cheapest source of electricity, and in October 2021 @AlboMP tweeted: “Aussie households have one of the highest uptakes of rooftop solar already, but we can harness more of that cheap and abundant energy”. But that so-called “cheap and abundant energy” is calculated by the world’s largest independent investment bank, Lazard, to be the most expensive form of electricity.

It is clear the push for net zero by 2050 will soon take in ever-wider sections of the economy. The electricity sector cannot do all the heavy lifting in reducing GHG (greenhouse gas) emissions, and for this reason attention here and elsewhere is turning to other sectors. Methane (CH4) and nitrous oxide (N2O) appear attractive GHG targets, and so agriculture is in their crosshairs. Before we turn to the battle shortly to be waged against methane and nitrogen, let us look at the state of play with renewable energy.


When converted into Australian dollars at 2021 PPP (purchasing power parity) rates, Lazard estimates are:

  • (Unsubsidised) rooftop solar: $A211-318 per MWh
  • State-of-the-art thin film PV utility scale: $A40-52 per MWh
  • Onshore wind: $A37-72 per MWh
  • Offshore wind: $A119 per MWh New coal is estimated to cost $A93-220 per MWh, with the higher estimate including 90% carbon capture and storage. Existing coal plant is $A60 per MWh. At first glance, it seems Albanese might have a case, but the devil is in the detail of what this (and Albanese) ignores. Moreover, by subsidising swathes of rooftop solar, Australian governments have driven cheap, dispatchable coal capacity out of the market.

The government’s target of 82% renewables is an expensive pipe dream.

As is now well appreciated, renewable electricity is intermittent, and depending on location, solar and wind alike have capacity factors around 30%. That is, electricity actually produced is more or less one-third of what it would be if the system ran all the time (a typical capacity factor for coal or nuclear power would be 85-90%). Because it is intermittent, storage is necessary, and producing a reliable renewable electricity system therefore requires an installed capacity of at least three to four times the average demand in order to replenish that storage.

The Albanese government is proposing to spend $20 billion on the transmission needed. Because renewables are a low-density energy source, the additional transmission costs are considerable. As is the cost of storage, which Lazard estimates (depending on circumstances) at $A189-401 per MWh.

Renewables are cheaper only if one ignores storage and transmission costs, and so the government’s target of 82% renewables is an expensive pipe dream and Albanese’s promise to reduce our power bills by $275 per year will inescapably come back to haunt him.

One is reminded of the great quote from George Costanza on the comedy show Seinfeld: ‘It’s not a lie if you believe it to be true’, and this may well be the case with the Prime Minister and the promise regarding renewable energy. But believing it is true does not make it so.

George Costanza


Moreover, the focus on the electricity system is only part of the picture. CSIRO estimates use of fossil fuels for electricity generation contributes only about 34% of Australia’s emissions of GHGs. Transport accounts for about 18%, stationary energy use for manufacturing, mining, commercial and residential sectors about 20%, agriculture about 15%, fugitive emissions (gas leaks) 10%, industrial processes 6%, and waste 3%.

GHGs do not only come from fossil fuel combustion. In addition to burning fossil fuels, carbon dioxide is released from microbial decay or burning of plant litter and soil organic matter. Methane results from leaks of natural gas or from coal seams, and from organic materials decomposing in oxygen-deprived conditions, including from digestion by ruminant livestock, stored manures, swamps, and rice paddies. N2O is generated by the microbial transformation of nitrogen in soils and manures, and is greater when available nitrogen exceeds plant requirements, particularly under wet conditions.

Simply targeting the electricity sector cannot therefore achieve all of the task government has set itself in reducing GHG emissions, and for this reason attention here and elsewhere is turning to other sectors, such as agriculture. CH4 and N2O are inevitably GHG targets for policy makers, which means agriculture is a target.

Methane from belching and farting ruminants, and leaks from natural gas production, are well-known GHGs with a Global Warming Potential (GWP) number of 27-30 (that is, it forces 27-30 as much global warming as carbon dioxide). That GWP number is calculated over 100 years, because that is thought to be the lifetime in the atmosphere of CO2, and some now prefer to give it a number in the 80s over a timespan a quarter of that. The GWP of methane makes it a favoured candidate for mitigation strategies, especially when the energy sector is already being squeezed.

Methane accounts for around 26% of Australia’s GHG emissions. It is worth noting that New Zealand—with which Australia enjoys a free trade relationship—excluded methane from agriculture and waste, which accounts for over 40% of their national emissions, from their ‘net zero’ emissions target. Instead, NZ has a separate target of a 24-27% reduction on 2017 levels by 2050, though few policies to achieve it.

Even more attractive is nitrogenous fertiliser use, because it produces N2O—an even more powerful GHG, with a GWP of 265. As we shall see, pursuit of nitrous oxide reductions has had serious consequences in the Netherlands and Sri Lanka, and they provide a salutary lesson for other agriculture-heavy economies.


Of perhaps greatest significance for Australia is the Global Methane Pledge, which was developed by the US and the European Union and launched at COP26 in Glasgow in late 2021. The Pledge is to reduce global methane emissions by 30% from 2020 levels by 2030. According to the Pledge website, it ‘could’ reduce Mean Global Temperatures by 0.2°C—could, that magic word that is virtually ubiquitous in climate science. Australia under the Morrison government did not sign on to the Pledge when it was launched, but it came into play as the Albanese government looked for reductions beyond the electricity sector. Within a month of its election the Albanese government announced it was considering signing the Pledge, though promising to first consult with the agriculture and natural gas sectors.

A specific methane target would have serious implications for the grazing industry.

The US and the European Union announced the Pledge at the meeting of the Major Economies Forum and at the UN General Assembly in September 2021, when just nine countries had signed on. It was then included in discussions at Glasgow, after which 122 countries had signed on. Those 122, however, do not account for even half of global emissions and many have negligible emissions—another example of legal scholar Joseph Weiler’s adage that those first to agree are those least likely to have to implement. China, Russia, India and Iran refused to join, and Australia declined to specify individual GHG targets within its target of ‘net zero by 2050’.

In response to Resources Minister Madeleine King announcing that joining the Pledge was under consideration, the Cattle Council of Australia pointed out the beef industry already had cut its net emissions by 58% and did not expect the new national emissions reduction goal of 43% to have an impact on Australian beef producers. Their optimism is probably misplaced, because a specific methane target would have serious implications for the grazing industry. Fully 42% of the agriculture sector’s emissions are from methane.

So far there has not been much action globally on methane as a result of the Pledge, but governments in Sri Lanka and the Netherlands have taken action against N2O emissions resulting from agriculture. Their experience provides salutary lessons for Australia as it takes the Pledge, because it will inevitably affect agriculture and not just the natural gas industry or coal seam methane production.

Nitrous oxide has a concentration in the atmosphere of about 333 parts per billion, increasing by about 1ppb annually. The main sources of emissions are fertilised agricultural soils and livestock manure, runoff and leaching of fertilisers, biomass burning, fossil fuel combustion and industrial processes, biological degradation of other nitrogen-containing atmospheric emissions, and human sewage. Soil cultivation, the use of nitrogen fertilisers, and animal waste disposal stimulate bacteria to produce N2O. Nitrogenous fertilisers used in agriculture not only boost production, but also produce N2O—a GHG with a GWP number of 265 (calculated over a century), but with such a low concentration in the atmosphere that it only warms the atmosphere by a small amount compared with carbon dioxide.

Nevertheless, policy makers have made reducing N2O emissions a goal; perhaps as an alternative to action in the energy sector, which in the EU is under pressure thanks to a combination of government policies and the dependence of Western Europe on Russian gas. Divestment campaigns first resulted in underinvestment in fossil fuels and then Putin played havoc with supplies after invading Ukraine (and having supplied funds to the anti-fracking movement in the West to maintain its dependence).

The use of nitrogenous fertilisers has come under pressure over environmental concerns other than climate change. The UN Environment Programme’s Economics of Ecosystems and Biodiversity for Agriculture and Food, launched in 2014, advocated that nations “steer away from the prevailing focus on per hectare productivity”. UNEP then launched its anti-fertiliser efforts from Sri Lanka in 2019, hosting a meeting in Colombo where it issued a ‘road map’ to pressure nations to halve nitrogen pollution.

A month later, Sri Lanka elected anti-fertiliser president Gotabaya Rajapaksa, who claimed—without any scientific evidence—that synthetic fertilisers caused kidney diseases. In April 2021, he banned fertiliser imports. Two months later, in June 2021, Sri Lanka hosted a UN-sponsored ‘Food System Dialogue’ to advance the UN’s broader anti-fertiliser agenda for the world. The Sri Lankan government was acting on the advice of Vandana Shiva, an Indian eco-feminist who announced (without a hint of irony) to the World Economic Forum meeting in Melbourne in 2000: “I am the leader of a worldwide movement against globalisation.”

Shiva has been called the ‘Gandhi of Grain’ for her opposition to genetically modified agriculture, a wave that has well and truly retreated. The comparison is somewhat overstated however, since Shiva has not followed the Mahatma’s tactic of staging hunger strikes to make a point. I also do not recall that he ever charged $40,000 and a business class airfare to make an appearance, as Shiva apparently did (reported by Keith Kloor in Discover magazine, 2014, in his article titled ‘The Rich Allure of a Peasant Champion’).

Shiva convinced the Sri Lankan government to move to organic agriculture in mid-2021, which it did with great gusto, lured by both the savings to be gained by reducing artificial fertilisers and the promise of a reduction in greenhouse gas emissions. Unfortunately, the policy proved disastrous. Agricultural productivity fell precipitously, and export earnings with it, so that it could not service the substantial debt run up in part under China’s Belt and Road Initiative. As environmentalist Michael Shellenberger noted, rice production fell 20%, prices rose 50%, and $450m worth had to be imported. Tea was particularly hard hit. It had previously generated annual exports of $1.3 billion, but production fell 18% (see also the article by IPA Research Fellow Dr Kevin You, Colombo Picked The Wrong Plan, in the Spring 2022 IPA Review).

Food prices escalated. Riots ensued. The government fell.

Food prices escalated. Riots ensued. The government fell. Sri Lanka began running out of fuel, food, and other essentials in the worst crisis since independence from Britain in 1948. Prime Minister Ranil Wickremesinghe, whose private home was set alight by protesters, agreed to step down. (Despite these policy failures, he became Sri Lanka’s president in July 2022.)

Not to be outdone, the Netherlands government in 2022 decided to demand a 50% cut in nitrogen pollution by 2030, leading to protests by farmers and concerns over global food shortages. The Netherlands—the world’s second largest exporter of agricultural products—has seen widespread protests and violence from farmers and even threats to politicians after they voted at the end of June 2022 to implement a plan to reduce livestock numbers by 30%. Again, the aim here is not related to the usual burps and farts of methane from ruminants, but emissions of nitrogen oxides from livestock manure and the use of ammonia as a fertiliser.

The Dutch government plan includes a radical cut in livestock. The government estimates 11,200 farms will have to close and another 17,600 farmers will have to significantly reduce their livestock numbers. This move was part of a policy adopted in 2019 to halve GHG emissions by 2030 and followed a court ruling in May 2019 that the way Dutch builders and farmers dealt with nitrogen emissions was in breach of European laws. The ruling caused delays in work on new highways, housing developments, airports, wind farms (ironically), and various other infrastructure projects with a combined worth of around €14 billion. The result has been protests and social upheaval. The farmer protests in the Netherlands have seen arson, the erection of barricades, desecration of flags, illegal dumping of waste, and the intimidation of elected officials, businesses, and environmental activists.

In Canada, Justin Trudeau also introduced restrictions on nitrogen emissions. In December 2020, his government unveiled a new climate plan, with a reduction in nitrous oxide emissions from fertiliser by 30% below 2020 levels by 2030—a restriction that will severely impact Canadian farming. As in the Netherlands and Sri Lanka, the result has been protests and upheaval.


While the GWP numbers of methane and nitrous oxide are alarmingly large, the practice of quoting them individually as if they were additive means their significance is overstated—especially when their tiny concentrations in the atmosphere are considered. Results in the laboratory do not reflect their performance in the atmosphere.

I asked William Kininmonth, former head of the National Climate Centre, about the significance of methane for climate forcing, and he suggested its importance is overrated. Methane occupies a narrow band of the longwave spectrum; it is orders of magnitude below CO2 in concentration; and decays in the atmosphere—through interaction with naturally occurring hydroxyl radicals—to CO2 and water vapour. The reason it gets such attention is that, in its active waveband, it strongly absorbs radiation.

To spell that out in greater detail, what are known as GHGs do not act independently of each other, and they do not actually work like a greenhouse, in which sunlight warms the inside of the structure and the glass prevents the energy being lost by convection. What happens in the atmosphere is that the molecules that comprise the atmosphere absorb photons, which excite them so that they emit energy, and this is what warms the atmosphere. Their seriousness as a GHG reflects their absorption of incoming light and subsequent re-radiation. But they are not additive.

Greenhouse gases are emitted during the manufacture of renewable energy technology.

All molecules are able to absorb some wavelengths of light, but no molecule absorbs all the available light. The probability of radiation being captured by a molecule of any compound varies between bands, a function of wavelength, and the numerical expression of that is known as the absorption cross-section. The main constituents of air—nitrogen, and oxygen—absorb mainly ultraviolet light, and no gases absorb in the visible wavelength range. The GHGs have emission bands in the infrared region, and they then warm up the atmosphere.

Methane is indeed a powerful GHG, but it constitutes only about 0.00017% (1.7 parts per million) of the atmosphere. Both methane and carbon dioxide (currently 416ppm or 0.042%) are well mixed, but water vapour—perhaps 2% of the atmosphere and mostly in the lower troposphere—absorbs much of the energy before it can reach GHGs in the upper atmosphere. In other words, any radiation methane might absorb has already been absorbed by water, which accounts for about 95% of the greenhouse effect and is thus the most important GHG. So, while methane is a very powerful GHG if we consider individual molecules, in the actual atmosphere its effects are masked by water.

Similarly, nitrous oxide is present in very small quantities, so its molecular GWP number is equally misleading. When it is considered that the concentration of N2O in the atmosphere in 2020 was estimated at 333 parts per billion (0.000333ppm, or 0.00000000333%), the high GWP number of N2O in isolation can, like methane, be seen to be of little importance in reality.

So, the problem with considering the GWP of different gases individually is that their absorption bands overlap. Former Obama Energy Department Chief Scientist Steven Koonin likens them to colours on a spectrum. If they overlap, reducing one simply allows another to become more prominent, without reducing climate forcing. W. A. van Wijngaarden and W. Happer have measured the actual (rather than modelled) effect of the main GHGs and concluded: “Doubling the current concentrations of CO2, N2O or CH4 only increases the forcings by a few per cent.”

Little is heard about other more powerful GHGs that are, rather inconveniently, emitted during the manufacture of renewable energy technology that is in addition to the considerable emissions of more mainstream GHGs. The steel in the tower of a wind generator, for example, requires perhaps 220 tonnes of coking coal plus steaming coal for cement. One analysis in 2016 (admittedly contested) even suggested that more energy goes into manufacturing solar panels than is produced by them in locations such as Germany and Switzerland, especially because they are mostly made in China using (inefficient) coal-fired electricity.

Moreover, making PV panels has a controversial GHG balance, because their manufacture involves the release of substances such as the solvents nitrogen trifluoride (NF3), which has a GWP number of 17,200, and sulphur hexafluoride (SF6), with a GWP number of 23,900. These fluorinated compounds are also used in and emitted from electric switchgear as insulators, so the larger transmission network required with low density renewables emits more than a conventional system.

Increases in CH4 and N2O will have very little discernible impact.

Scientist Ferruccio Ferroni estimated that the CO2 equivalent emissions from PV Solar in Germany was 978g per kWh—greater than gas (400g) and even coal (846g). But those emissions occur mostly in China, where the PV panels are mostly made, so it seems they can be safely ignored by Western policy makers.


On 23 October the Minister for Climate Change and Energy, Chris Bowen, announced Australia would sign the Global Methane Pledge and ‘invest’ $3 billion to support investment in low emissions technology, component manufacturing and agricultural methane reduction, plus another $8 million to support commercialisation of Asparagopsis, a red algae that allegedly reduces methane emissions when used as a livestock feed supplement (although other research suggests it may do more harm than good).

Minister Bowen claimed the pledge would contribute to the avoidance of 0.2 degrees of warming. The latest science says otherwise.

Coe, Fabinski, and Wiegleb, writing in the International Journal of Atmospheric and Oceanic Sciences in August 2021 put the current forcing effect of both CH4 and N2O combined at just 0.3 degrees and any future doubling, including the positive feedback effects of water vapour, at an almost undetectable 0.06 and 0.08 degrees respectively. They concluded that “increases in CH4 and N2O will have very little discernible impact”.

The Global Warming Potential numbers of methane and nitrous oxide make them, superficially, attractive candidates for mitigation, especially with recent energy policy failures, but their global warming potential in laboratory measurements is unlikely to be realised in the actual atmosphere. There, their effects are dwarfed by that of tropospheric water vapour which largely precludes the effect of increases in well-mixed GHGs. Their extremely small concentrations mean that increases are likely to have very small effects—and so also with any decreases forced by policy change.

The Global Methane Pledge and attempts to reduce nitrous oxide emissions by reducing fertiliser applications are unlikely to be effective in addressing climate change. Moreover, they are likely to be extremely inefficient economically, yielding minimal benefits for considerable cost. Bowen’s $3 billion will be wasted.

Aynsley Kellow is Professor Emeritus of Government, University of Tasmania; a former Expert Reviewer for the IPCC; and was a Special Correspondent for the Institute of Public Affairs during COP26 in Glasgow in November 2021. His account, Globe Trotters, appeared in the Summer 2021/22 edition of the IPA Review.

This article from the Summer 2022 edition of the IPA Review is written by Professor Emeritus of Government Aynsley Kellow.

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