Duality in Climate Science - by Kevin Anderson

The commentary demonstrates the endemic bias prevalent amongst many of those developing emission scenarios to severely underplay the scale of the 2°C mitigation challenge.  In several important respects the modeling community is self-censoring its research to conform to the dominant political and economic paradigm.  Moreover, there is a widespread reluctance of many within the climate change community to speak out against unsupported assertions that an evolution of ‘business as usual’ is compatible with the IPCC’s 2°C carbon budgets.  With specific reference to energy, this analysis concludes that even a slim chance of “keeping below” a 2°C rise, now demands a revolution in how we both consume and produce energy.  Such a rapid and deep transition will have profound implications for the framing of contemporary society and is far removed from the rhetoric of green growth that increasingly dominates the climate change agenda.

The value of science is undermined when we adopt questionable assumptions and fine-tune our analysis to conform to dominant political and economic sensibilities.  The pervasive inclusion of speculative negative emission technologies to deliver politically palatable 2°C mitigation is but one such example.  Society needs scientists to make transparent and reasoned assumptions, however uncomfortable the subsequent conclusions may be for the politics of the day.

June’s UNFCCC Bonn Conference reiterated the headline ‘conclusions’ of November’s IPCC Synthesis Report, which itself was heralded as delivering clear messages to policy makers.  As the Financial Times noted, meeting the 2°C dangerous ‘limit’ would “only cause an annual 0.06 percentage point cut in … economic growth”, a small cost that would, according to the UK’s Guardian, rise by less than 50% even if emissions reductions were delayed to 20302.  In similar optimistic vein, the US Associated Press and Hindustan Times reported that maintaining “the temperature rise below a level that many consider dangerous” may require emissions from fossil fuels “to drop to zero”, but not before “the end of this century”.  The Sydney Morning Herald concluded that staying below 2°C would require “a fairly strong level of action on greenhouse gas emissions” with, ChinaDaily reporting that in delivering the requisite action “the solutions are many and allow for continued economic and human development.”

Based on such reports it is easy to be left with the impression that the shift away from fossil fuels needs to be much more an evolutionary transition than an immediate revolution in how we use and produce energy.  Moreover, it could be suggested that delaying action until 2030 would give more time for considered reflection of the options, yet still only have a very marginal impact on economic growth (i.e. less than a 0.1 percentage point cut) – not a bad exchange perhaps?

In stark contrast, this commentary concludes that the carbon budgets needed for a reasonable probability of avoiding the 2°C characterization of dangerous climate change demand profound and immediate changes to the consumption and production of energy.  The IPCC’s own 1,000 GtCO2 carbon budget for a “likely” chance of 2°C, requires global reductions in emissions from energy of at least 10% p.a. by 2025, with complete cessation of all carbon dioxide emissions from the energy system by 2050. 

Diluting the message
Whilst the endeavors of the IPCC, since its inception in 1988, are to be welcomed, I have grave reservations as to how the implications of their analysis are being reported.  This is not solely the failure of incisive journalism, but is also the outcome of repeated and questionable commentary from some experts engaged in the IPCC process.  Even the press release for the IPCC’s Synthesis report provided an optimistic spin, with the then IPCC chair stating that “To keep a good chance of staying below 2ºC, and at manageable costs, our emissions should drop by 40 to 70 percent globally between 2010 and 2050, falling to zero or below by 2100”[emphasis added]. Moreover, the Co-Chair of the IPCC’s section on reducing emissions made the all-important comment that mitigation costs would be so low that “global economic growth would not be strongly affected” - echoing the conclusion of the recent and influential report from The New Climate Economy. 

But does the IPCC’s own analysis support the upbeat rhetoric of evolution as opposed to the more challenging and fundamental language of revolution?

Certainly such evolutionary conclusions are forthcoming from many highly complex integrated assessment models (IAMs) – whereby an understanding of prices, markets and human behavior is brought together with the physics of climate change to generate ‘policy-relevant’ and cost-optimised emission scenarios.  These typically offer highly optimistic futures through a combination of very early peaks in global emissions and a belief that negative emission technologies will prove practically and economically viable in removing CO2 from the atmosphere (hence the reference to “or below” zero emissions in Pachauri’s earlier statement).

‘Geo-engineering’ as systemic bias
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As it stands, the expedient and ubiquitous use of speculative negative emissions to expand the available 2°C carbon budgets, implies a deeply entrenched and systemic bias in favor of delivering politically palatable rather than scientifically balanced emission scenarios.  Nowhere is this more evident than in the IPCC’s scenario database.  Of the 113 scenarios with a “likely” chance (66% or better) of 2°C (with 3 removed due to incomplete data), 107 (95%) assume the successful and large-scale uptake of negative emission technologies.  The remaining 6 scenarios all adopt a global emissions peak of around 2010. Extending the probability to a 50% chance of 2°C paints a similar picture.  Of the additional 287 scenarios, 237 (83%) include negative emissions, with all the remaining scenarios assuming the successful implementation of a stringent and global mitigation regime in 2010.

In plain language, the complete set of 400 IPCC scenarios for a 50% or better chance of 2°C assume either an ability to travel back in time or the successful and large-scale uptake of speculative negative emission technologies.  A significant proportion of the scenarios are dependent on both ‘time travel and geo-engineering’.

Read more at Duality in Climate Science