The Justification for Net Zero Has Vanished with the Demise of RCP8.5

Any justification for Ed Miliband’s Net Zero climate policy, whether real or imaginary, has vanished with the official abandonment by the IPCC of the scariest concentration scenario RCP8.5. Even Tony Blair can now perceive that the pursuit of Net Zero is unwarranted and harmful to Britain.

It’s now 20 years since the publication of the ‘Stern Review on the Economics of Climate Change‘ in 2006: a review commissioned by Gordon Brown, then Chancellor of the Exchequer, in a Labour government led by Prime Minister Tony Blair. This review began the UK-drive towards the crazy carbon-phobic policies which are helping to impoverish the nation, aided by unrealistic scenarios. There is some irony that Blair is now calling for the abandonment of Net Zero: when the Review was published he warned about the disaster that would come from inaction. It was his government that helped to pave the way for the excessive climate policies we have today, and scaring people was a tool of risk management, as Lord Giddens noted in the Lords March 1st 2005.  

The Stern Review claimed that the risk from global warming was such that there was imminent danger to international standards of living. But in reality, the review made totally unrealistic claims in its assessment of warming and economic impacts. It brazenly asserted that there was more than a 50% risk of global temperatures rising by 5°C by the end of the century. Given that scenario, the cost of inaction would be 5% of global GDP per annum. The review called for nations to spend between 1% and 2% of GDP as a matter of urgency to reduce carbon dioxide emission by 80%. It was effectively a call for economic self-flagellation. The scary scenario outlined by Stern’s review was based on the ‘Special Report on Emissions Scenarios’ (SRES) strong A2 pathway, which morphed into the RCP8.5 which is familiar to us. The Representative Concentration Pathways (RCPs) were first proposed in 2007 and adopted by the IPCC’s ‘Fifth Assessment Report’ (AR5) of 2014. While RCP8.5 was an extreme and unlikely scenario, like its forerunner SRES A2 it was widely treated as the ‘business as usual’ case by climate alarmists.

Lord Nigel Lawson, former Chancellor of the Exchequer in the Thatcher government, responded critically to the Stern Review in a lecture in 2006 for the Centre for Policy Studies. This was expanded into the book An Appeal to Reason, published in 2008. Lawson pointed out the uncertainty in the IPCC modelling: the SRES A1 pathway, for example, had a spread of between 1°C and 6°C temperature rise by 2100 (2.0°C to 5.4°C for A2). Given this spread, the high temperature rise outcome must be considered a low likelihood, certainly much less than 50%.

Further criticism by Lawson was that these high scenarios had assumed unrealistic population growth rates and not modelled the efficiency of energy use accurately. Energy intensiveness has declined in the past 50 years. In terms of economic costs in agriculture and food production, the Stern Review had not taken into account the benefit of higher carbon dioxide levels for plant growth (global greening) and overlooked the ability of farmers to adjust as necessary to a changing climate by growing different or hardier crops.

Lawson pointed out that the cost of decarbonising the economy is uncertain, but would be enormous. He quoted figures (in 2006 prices) of between $80 billion and $1,100 billion a year globally, with the cost falling primarily on Western nations. The higher figures are likely if society moves more quickly to cut carbon, which is what Stern called for. The installation of renewable energy infrastructure also requires subsidies and back-up in the form of carbon fuel power stations. The cost of de-carbonising would also impact poorer consumers and nations more, especially as hydrocarbon fuel prices and subsidies are forced to increase.

In sum, the Stern Review miscalculated the risk of a 5°C temperature rise by 2100 and overstated the economic impact of climate change by not taking into account the ability of agriculture to adjust, nor the economic benefit of global warming in some instances. The review had also not taken into account the extremely high costs of removing carbon fuels from the economy. When those errors are acknowledged, any justification for a reduction in carbon emissions by 80% (or 100% i.e., Net Zero) is removed.

Instead, Lawson argued that it would be more beneficial to direct invest towards adapting to a changing climate instead. The obligation of the West is then to extend finance and technological know-how to poorer nations through development programmes. One reason for doing this is that some of the problems societies faces are not new, such as sea level rises, and so direct mitigation through development would offer enhanced protection even without the question of climate change.

The same economic arguments have continued in recent years, with RCP8.5 often treated as ‘business as usual’, even though it is now officially considered an implausible scenario by the IPCC. As with the errors of the Stern Review, the scenario assumed a massive increase in coal production and higher population growth rates while ignoring technological advances in energy efficiency. For example, the internal combustion engine has nearly doubled in energy efficiency in 50 years. But RCP8.5 has continued to be used to justify the drive towards Net Zero in recent years. The impact of doing little or nothing to move away from carbon use is overstated, while the cost of action is understated or hidden in subsidies that are passed onto consumers.

It’s becoming increasingly evident that any justification for Net Zero has been demolished, as even Tony Blair has noticed. In a recent foreword to a report of the Tony Blair Institute for Global Change, ‘The Climate Paradox: Why We Need to Reset Action on Climate Change‘, he wrote that “any strategy based on either ‘phasing out’ fossil fuels in the short term or limiting consumption is a strategy doomed to fail”. He observed that ordinary people are increasingly sceptical of excessive climate action when other nations are not following suit. At the same time, he noted that the tone and arguments of the climate alarmists are “riven with irrationality”. Of course, Blair has an eye on the establishment of power-hungry AI data centres and the promotion of digital ID, and he still calls for the installation of hugely expensive carbon capture technologies, but it’s a step in the right direction.

The economic justification for an 80% reduction in carbon use, or Net Zero as it is now, was always flawed, based on unrealistic inputs into the scariest climate scenarios. But now with the RCP8.5 pathway officially acknowledged to be implausible, any remaining reason to pursue Net Zero has vanished. The economic case now should direct investment towards developing mitigation strategies to alleviate floods and droughts globally (whether or not they increase as a result of a changing climate), combined with improved weather forecasting and impact modelling and technology transfer to developing nations.

Andrew Sibley is a semi-retired chartered meteorologist with an MSc in Environmental Decision-Making and an MPhil in Theology.