- 2022-23 is 30th anniversary of the Rio Earth Summit and the UNFCCC
- UNFCCC objective is to contain “dangerous” human-caused global warming
- Expert advice is that “dangerous” means warming greater than 3.0°C by 2100
- Human-caused emissions have stopped growing, ever since 2010
- UNFCCC has finally discarded the high 2009 “pathway” scenarios
- UNFCCC now predicts warming of 2.5°C for 2100 AD, with existing policies (BAU)
- With Net Zero policies, UNFCCC prediction reduces to 1.7°C for 2100 AD
- Implementing Net Zero (0.00625°C/decade) : tiny benefits, huge costs
- Paris Agreement target is political, not scientific. But it will likely be met.
This year marks the 30th anniversary of the United Nations’ drive to manage “dangerous anthropogenic global warming” (DAGW). New Zealand signed the UNFCCC at the ‘Rio Earth Summit’ on 12 June 1992 and formally ratified it on 16 September 1993. Most other countries also ratified it in 1993.
The UNFCCC aims to contain “dangerous” human-caused global warming
“The ultimate objective .. is stabilization of greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system. Such a level should be achieved within a time-frame sufficient to allow ecosystems to adapt naturally to climate change, to ensure that food production is not threatened and to enable economic development to proceed in a sustainable manner.” [emphasis added]
The word “dangerous” was deliberately left undefined. This made it possible for all countries to adopt the Convention, including those who did not see DAGW as an actual or eventual threat. Who could argue with acting against “danger”? Convention parties were assured that scientific research on possibly dangerous levels of human emissions would be intensified.
The scientific background to the Earth Summit was a 1992 update of the 1990 WG1 Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) which found no physical (as opposed to modelled) evidence of DAGW, and reported that “unequivocal detection of the enhanced greenhouse effect is not likely for a decade or more”. While temperatures had risen by 0.3 – 0.6°C over the previous century, this “was the same magnitude as natural variability.”
However, the IPCC’s 1992 models predicted that 21st century global warming would increase at the unsustainable rate of 0.3°C per decade to be about 4.6°C by 2100; and average sea level rise would be about 6cm per decade. If they came to pass, these very high levels might well be found to be “dangerous”.
“Dangerous” requires warming greater than 3.0°C
Over the last few thousand years, while the Earth’s average temperature has remained in a stable range of about 15°C ± 2°C , the warmer eras have always been more popular than the cooler times. Meteorologists refer to warmer periods as “optimum”.
After a very cold period like the Little Ice Age (1300-1850) global warming first produces a slew of benefits – longer growing seasons, frost-free nights, fewer deaths from cold, the “greening” of the Earth, etc. Warming causes no net harm unless the temperature rises “too much”.
“How much is too much” has been at the centre of scientific and economic debate from the outset. Early on, it was recognised that any aggregate cost benefit analysis (CBA) of global warming must combine climate and economic data into highly-complex Integrated Assessment Models (IAMs).
IAMs evolved rapidly. For the past decade or so, the DICE, FAIR and PAGE IAMs have been relied upon by successive US administrations to calculate “the social costs of carbon”.
Professor Richard Tol of FUND published “The Economic Effects of Climate Change”, a seminal research paper which summarises all the 14 separate studies that had been published in peer-reviewed journals prior to 2009. He found that there is unlikely to be net global benefit to human or planetary welfare from warming till temperature has increased by 2.2 degrees from 2009 levels, which is about 3 degrees above pre-industrial temperatures (see Fig 1 graph on page 35). This is before taking adaptation into account so it is very conservative.
In 2014, Professor Tol updated his paper, obtaining results that were not materially different.
The lead author of the DICE model is Professor William Nordhaus of Yale University, who is the acknowledged world leader in the estimation of the economically optimal climate goal. DICE put the CBA optimum at 3.5°C. In 2018, Nordhaus was awarded the Nobel Prize in Economics for his findings of “interactions between society, the economy and climate change”.
In his Nobel Prize Lecture at page 452, Professor Nordhaus described the output of DICE:
The base path (which is essentially the path the globe is following) continues to have rising temperature, passing 4°C by 2100. In the DICE model, it is essentially infeasible to attain the stringent temperature target of 1.5°C, and the 2°C path requires negative emissions in the near term. Another finding, much more controversial, is that the cost-benefit optimum rises to over 3°C in 2100 – much higher than the international policy targets. Even with the much more pessimistic alternative damage function, the temperature path rises to 3°C in 2100.
While there will always be others to argue, it is clear that the best available expert advice says that AGW is beneficial to the planet, unless and until it exceeds 3.5°C. While we may not know the exact lower bound of “dangerous” temperature, our best estimate is that it cannot occur unless and until GASTA rises higher than 3.0°C.
Human emissions have stopped growing since 2010
In 1992, Convention parties had good reason to expect that future global emissions would accelerate in leaps and bounds – to double and re-double over the next few decades, on a business-as-usual (BAU) basis. The data showed that emissions had grown by 140% in 30 years:
Global CO2 Emissions from fossil fuel and industrial processes (in billions of Mt)
Decade Emissions Growth Rate
1970 14.9 5.51 58.68%
1980 19.49 4.59 30.81%
1990 22.75 3.26 16.73%
Perhaps the IPCC report and/or the Earth Summit sparked greater awareness on the part of industries everywhere that energy efficiency was essential. Certainly the oil price shocks of the 1970s had led to massive efforts by manufacturers to squeeze more miles-per-gallon, and these innovations were starting to bite by the late 1980s – average fuel economy rose by 40 percent from 1974 to 1991). Also, enormous increases in productivity began to flow from the advent of the Information Age – first computers and then the internet.
The data outcomes over the ensuing 30 years were nothing short of startling:
Decade Emissions Growth Rate
2000 25.23 2.48 10.9%
2010 33.34 8.11 32.14%
2020 34.81 1.47 00.04%
The huge bulge in the noughties reflected the massive growth in the BRIC countries (especially China) – the Millenial Goal of lifting a billion people out of extreme poverty was achieved during this singular decade.
But then came the GFC and quieter times – although efficiency enhancements continued to roll out across the world and the historical link between energy use and prosperity became more nuanced. The result during the past decade has been both spectacular and gratifying. One could say that the goal of the UNFCCC has been fully achieved.
The UNFCCC has finally discarded the 2009 “Pathways”
Representative Concentration Pathways (RCPs) were developed in 2009 and used for climate modelling and research for the IPCC’s AR5 in 2013. The RCPs, originally 2.6, 4.5, 6.0 and 8.5 , labelled scenarios of radiative forcing in 2100. After AR5, they were joined by Shared Socioeconomic Pathways but remained essentially unchanged.
Although these scenarios were mere guesses, with no scientific backing, they had a huge impact on the IPCC’s temperature predictions. For example, the 2100 range under RCP2.6 was 0.3 — 1.7°C, while under RCP8.5 it rose to 2.6 – 4.8°C. Sea level rise was 0.26m under the low scenario and 0.82m under the high one.
When the RCP’s were selected in 2009, human-caused emissions were rising at a rate of nearly 33% per decade. However, just a year later, that rate plunged – and the growth over the following decade was negligible.
The realisation that the high scenarios were fanciful was slow to sink in, especially because US billionaires spent a fortune on promoting RCP8.5, but criticism rose louder after the publication of Ritchie and Dowlatabadi (2017), to become deafening by 2022
In a January 2020, BBC News report “Climate change: Worst emissions scenario exceedingly unlikely” climate scientist Zeke Hausfather, noting that RCP8.5 assumes a 500% increase in coal usage, states “global coal use peaked in 2013 and it’s been ﬂat since then” and “what originally was a worst case (scenario) with less than 10% chance of happening is today, exceedingly unlikely”. He claims that: “Very few scientists realised that RCP8.5 was originally a 90th percentile outcome, not a most likely or business-as-usual outcome”?
For the UNFCCC’s COP27, in early November 2022, publications by the International Energy Agency (IEA), United Nations Environment Programme (UNEP), and Climate Action Tracker (CAT), all offered revolutionary new temperature predictions for the remainder of the 21st century. All three openly discarded both RCP8.5 and RCP6.0 in favour of 1.5 – 2.7°C pathways [see Figure 2.1 here]. [See also “This Changes Everything!”]
Revolutionary new UNFCCC prediction – warming of 2.5°C by 2100 (BAU)
So, the growth of anthropogenic inputs (emissions)to enhanced greenhouse warming is down – way down. The direct outputs are the incremental global levels of atmospheric CO2 but, for unexplained reasons, this dataset does not yet appear to reflect fluxes in emissions growth.
More importantly, the outcomes of the flat growth in emissions ought to be a closely-correlated decrease in projections of future emissions. This has certainly happened. The following summation is from p14 of the December 2022 public report on COP27 by the UK Climate Committee:
“Estimates for 2021 and 2022 emissions suggest a plateauing around 2019 levels following the rebound from reduced emissions in 2020 due to the COVID-19 pandemic. This follows a slowing in CO2 emissions growth from around 3% per year during 2000-2009 to around 0.5% per year since 2010.
Scenarios from the International Energy Agency (IEA), United Nations Environment Programme (UNEP), and Climate Action Tracker (CAT) that fully implement all NDCs and Net Zero targets point towards 1.7°C,* 1.7°C and 1.8°C of warming respectively by the end of the century. These are all central estimates with 50% probability.
These NDC and Net Zero ambitions are not fully backed by actions, with assessments of present policies suggesting warming of 2.5°C (IEA), 2.6°C (UNEP) and 2.7°C (CAT).
The increase in the cost of fossil fuels due to the energy crisis, the continued progress in renewables deployment and countries’ strengthened targets and policies suggests the world may be turning a corner (Fig 2.2).”
In brief, the UN advisers (who use different estimating methods) seem unanimous that the global average surface temperature anomaly (GASTA) will be about 2.5°C (±0.7°C) by 2100 under policies currently in force. They expect this outcome could reduce to about 1.7°C (±0.7°C) if all the promises of all countries, including Net Zero targets, were to be fully delivered. The aspirational goal of 1.5°C is no longer mentioned.
Which raises a very important question: should we bother to chase that last 0.5°C degree (over 80 years) between the current prediction and the Paris Agreement Target of 2.0°C. Dr Judith Curry notes that “The policy implications of the 2.5°C prediction are enormous”.
Clearly they have not yet sunk in to the consciousness of the world’s climate bureaucracy. If the world is “turning a corner” under existing policies, why press for all the economic destruction associated with Net Zero by 2050 promises?
0.00625 deg/decade: trivial benefits, huge costs
In his Nobel Prize lecture (p 451), Professor Nordhaus pointed out that:
‘However attractive a temperature target may be as an aspirational goal; the target approach is questionable because it ignores the costs of attaining the goals. If, for example, attaining the 1.5°C goal would require deep reductions in living standards in poor nations, then the policy would be the equivalent of burning down the village to save it. If attaining the low-temperature path turns out to be easy, then of course we should aim for it”.
Half-a-degree reduction over 80 years would require average reductions of 0.00625 of a degree in each decade. Does anybody honestly believe that a global average variation of six-thousandths of a degree in any 12-month period is likely to make the slightest difference to weather outcomes? Seriously?
- To begin with, there is no science behind the 2°C target set by the Paris Agreement. As Professor Roger Pielke Jr points out, the nice round number – TWO – is “Arbitrary and Untethered”, while the 1.5°C aspirational goal is pure politics . (Pielke notes that ‘anchoring’ figures are better for long-term policy purposes than scientific rationales, which might be undermined overnight by new findings).
- In any given decade, nearly half the world’s weather zones experience a cooling trend while slightly more than half are warming. The 0.06°C/decade is the calculated/estimated difference between two very large and very rough numbers. The temperature measurements are rife with uncertainties, estimates, rounding, inhomogeneities and variable adjustment techniques. The flaws of the data (not included in the error bars) exceed 0.006°C per annum many times over.
- The UN’s BAU prediction of 2-5°C (actually a range of 1.8 – 3.2°C) is not statistically different from the 2.0°C target. The eventual actual difference by 2100 (if any) comes down to mere chance.
- The current BAU prediction of 0.175°C/decade is exactly the same trend as we have experienced over the past 40 years (according to the HadCRUT5 land dataset). That trend has seen a huge reduction in lives lost to weather extremes as well as record improvements in all relevant global indicators, such as life expectancy, poverty reduction and food availability. There is nothing to fear from this modest and static rate-of-warming.
- If natural variability were to be measured, it would almost certainly exceed 0.00625°C in every decade. The IPCC has declined to measure natural impacts (such as year-to-year swings of several tenths of a degree from ENSO, volcanic eruptions, and multidecadal ocean oscillations) on the assumption that they will be swamped by human-caused increases in the long term. But, as Curry points out – once you cut the anthropogenic warming in half, you lose any rationale for ignoring natural climate variability.
- The 2.5°C prediction takes account of current and pending decarbonisation policies but is necessarily agnostic regarding any new low-carbon energy technologies between 2030 and 2100. Just as technology has evolved rapidly over the past 80 years, it is highly likely to evolve at an even faster pace over the next 80. Just one decision – China replacing coal with 4G nuclear by 2140 – could reduce the BAU prediction by >0.5°C.
- Over the past 30 years, the UNFCCC has, without fail, exaggerated the “danger” of AGW and under-estimated the market-driven advances of technology. Unless human nature changes, it will ever be thus. Its BAU predictions have steadily fallen from ‘exponential’, to 5.0°C, to 2.5°C. – and there is plenty of time for the 2022 prediction to be halved again before 2100.
The above considerations bolster the intuitive view that only trivial global benefits are likely to flow from any additional climate policies anywhere. Now… what about the cost?
Economist Bjorn Lomborg has carefully followed the published research on the net economic costs of implementing promises to achieve Net Zero emissions by 2050. A simple Google search discloses some of the results:
Oct 2021: “USA going net zero will cost more that $11,300 per person per year in 2050 according to new Nature study. That is almost 500x as much as the average American is willing to pay”
March 2022: “The Bank of America has found that achieving net-zero will cost US$150 trillion over 30 years – almost twice the GDP of every single country on earth. The annual cost of US$5 trillion is more than all the world’s governments and households spend every year on education”.
Oct 2022: “McKinsey estimates that getting to net-zero will cost Europe 5.3% of its GDP in low emissions assets every year. That’s $US200 billion annually just for Germany – more than it spends on annually on education, police, Courts and prisons combined”
Jan 2023: “The Bank of America’s net-zero estimate of twice the GDP of the Earth is based on the heroic assumption that big emitters China and India will cut the most. But India says it will only move towards net-zero if the rest of the world pays it $1 trillion by 2030”.
Jan 2023: “In a new study, McKinsey finds most of the poorest nations in Africa would have to pay more than 10 per cent of their total national incomes every year towards climate policy – more than their combined spending on education and health. This is not only implausible but also immoral on a continent where more than half a billion people still live in abject poverty”.
UNFCCC mission accomplished
The readily-available data speaks for itself – the benefits are trivial and the costs are huge. Only billions of dollars spent on lobbying and propaganda by the super-rich are keeping the Net Zero dream alive.
But Net Zero is a dead man walking. Pielke’s Iron Law of Climate Policy (when policies focused on economic growth confront policies focused on emissions reductions, it is economic growth that will win out every time) will inevitably prevail in democracies.
While the corporate media of the developed world may suppress the century’s biggest climate story – the halving of the UN’s warming predictions – the Treasury Departments of Governments everywhere have no option but to recognise the current science.