The need for radical climate interventions: six years to secure humanity's ‘liveable future’

This is the authors' abstract. We don't add key points for this paper.

‘If you're not part of the solution, you're part of the problem’. (attrib.) Harry Emerson Fosdick/Eldridge Cleaver Manmade global heating is occurring more rapidly and intensively than forecast by the Intergovernmental Panel on Climate Change (IPCC) in 2018 [1]. In July 2023, the Earth experienced its highest mean monthly land and sea surface temperatures since records began [2], global mean surface temperature twice breaching 1.5°C above pre-industrial levels (the sustained target identified in the 2015 Paris climate agreement) [1]. Moreover, there is ‘no credible pathway to 1.5°C in place’ today [3]. Indeed, several researchers have forecast rises of 2°C (or even as high as 2.4°C) by 2045–2050 [4-9], highlighting problems in the IPCC's use of pooled models, publication lags, its under-appreciation of positive climate feedback loops and natural conservatism in achieving global consensus (‘erring on the side of least drama’). Heating ≥ 2°C would bring ‘numerous risks to natural and human systems’ (at ‘multiple times (the rates) currently observed’ [10]), including biodiversity loss; food and water shortages; extreme weather events; outbreaks of infectious disease; mass migration; and geopolitical crises [3]. Any further delay in radically reducing so-called greenhouse gas emissions will risk missing ‘a brief and rapidly closing window to secure a liveable future’ [10]. Events may accelerate even faster than this. Occurring slowly, and then very rapidly once ‘climate tipping points’ are exceeded, self-perpetuating positive feedback loops can interact in ‘climate tipping cascades’, amplifying global heating. Five of nine core global tipping elements and their climate tipping points have already been breached, increasing the likelihood of further breaches, and potentially accelerating global heating towards 2–3°C by 2050 [11]. For example, thawing carbon-rich polar ice shelves and permafrost drives the release of methane (83 times as powerful a greenhouse gas as carbon dioxide over the first 20 years after its release), reduces reflection of solar energy back into space and increases the loss of winter sea ice (contributing to sea level rises and altered ocean currents). Some tropical forests have become net carbon dioxide emitters because of heating-related deforestation and altered local weather patterns. The shift of multiple weather systems into new and dangerous states (for instance, through the collapse of major ocean circulations and movement of the northerly jet stream) are likely to precipitate extreme weather events, and thus food and water shortages. Individual and compound cascade effects increase the likelihood of high-consequence (‘fat tail’) geopolitical and economic threats to humanity and could plausibly precipitate the collapse of human civilisation within 30 years (360 months, c. 2050) [6, 9]. Humanity has always faced seemingly insoluble existential crises. Virtually all previous civilisations have collapsed, including several after ecological disasters [12], but this will be the first time that humanity has caused a global collapse knowingly and whilst documenting it. The predicted 30-year time horizon should shake humanity's collective complacency: ‘it won't happen in my lifetime’ becomes redundant as any justification for continuing the current rate of personal or societal contributions to climate change. The collapse of global civilisation is not inevitable, but all of us need to act quickly and decisively to avoid breaching the 1.5°C threshold identified by the IPCC. Manmade carbon dioxide emissions need to halve by 2030 compared with 2010 levels and reach net zero by 2050 [1] to limit global heating ≤ 1.5°C, or 45% by 2030 and reach net zero by 2070 to remain ≤ 2°C. Net zero does not mandate cessation of manmade carbon dioxide emissions, merely that they occur at the same rate as their ‘draw down’ (removal) from the atmosphere. Many have called for radical decarbonisation and further research. Radical decarbonisation needs to proceed urgently according to actions based on current knowledge and informed opinion. Certainly, research should be performed (e.g. into carbon capture and storage technologies) but should not delay immediate action to reduce emissions. However, we cannot wait for certainty, or rely on innovation and technology to engineer us out of imminent climate collapse. Even if the IPCC 1.5°C and 2°C target horizons remain valid, we will need to reduce greenhouse gas emissions by over 10% year-on-year to 2030 (i.e. approximately double the 5.4% annual emissions reduction measured during the COVID-19 pandemic ‘anthropause’ of 2020). This applies as much to anaesthesia as other fields of human endeavour. We need to commit immediately to radically decarbonising our personal lives (Fig. 1 and online Supporting Information Figure S1) and engage professionally and politically in implementing similar strategies at the institutions in which we work and, more broadly, throughout the societies in which we live [13]. Recent controversy about the relative contribution of inhalational anaesthetic agents to radiative forcing (global heating) has prompted calls for further research. Although this might improve data accuracy and the refinement of volatile capture technologies, it would not change the necessary action of abandoning the global use of these potent chlorofluorocarbons [14]. As leaders and opinion formers, anaesthetists need to become vocal public advocates of ‘green’ healthcare strategies extrapolated from the limited research already published [15]. This concurs that radical reductions in healthcare have positive effects on the triple bottom line of climate accountability (planet/people/profit) by decreasing direct (polluting) and indirect (life cycle) emissions to a far greater degree than reuse, recycling or re-engineering strategies [16]. Traditionally, such reductions are delivered by improving public health as well as healthcare efficacy and efficiencies. Morrison et al. define more ‘radical’ interventions for climate-impacted systems (including healthcare) as ‘those that ultimately address the root causes of climate change along structurally transformative and systemic pathways’ (i.e. capitalism, materialism, asymmetric power relations and the ‘lock-in’ of exploitative and extractive systems), in contrast to more ‘symptomatic’ interventions that maintain the status quo [17]. Understandably, effecting radical systemic change within globalised capitalist societies to bring about climate rescue within the timeframe needed can produce the kind of existential paralysis individuals experience in the face of the enormity of that task. As well as countering allegations of negative alarmism and extremism, Morrison et al. go on to consider ‘the art of the possible’ by defining six ‘shades of radical’, each reflecting the extent to which that intervention disrupts the status quo to address the root drivers of climate change (Table 1). Theatre waste recycling ‘green theatre’ Rationing To deliver the magnitude of climate rescue necessary (45% reduction in carbon dioxide emissions) within the time horizon allotted (six years, 2030), it is worth considering the deep radical interventions listed in in further depth. No country will be able to insulate itself from future climate-related insecurities, regardless of its relative wealth [3]. To date, governments in higher-income countries have relied on outsourcing climate change solutions to industry, rather than using their own powers to address the root drivers of climate change through deeply radical societal change. Although technological solutions will play an important part in emission reduction and carbon drawdown, none currently exist at scale for this purpose. Therefore, active participation in local and national democratic elections remains the most potent and immediate driver of deep radical change available to individuals for influencing national and international climate agendas. Voters can change climate policies by communicating their demands for climate action and voting accordingly. Healthcare's climate footprint is equivalent to 4% of global net carbon dioxide emissions. Healthcare in the UK contributes approximately 4% of the national total, in Australia 7% and in the USA 10%. If the healthcare system in the USA were a country, it would rank 13th in the world for greenhouse gas emissions [20]. Nearly 12% of global gross domestic product is spent on healthcare. No publicly or privately funded economic model of healthcare worldwide currently incorporates environmental costs but redistributing this enormous sum of money – almost £10 trillion ($12.3, €11.5 trillion) – to low-carbon activity could fund very significant climate change mitigation. Some authors have insisted that healthcare's outsize environmental footprint can be reduced without compromising quality [21]. Although there are many moral difficulties inherent in rationing something normally considered critical to human continuance, the intensity and breadth of healthcare as currently provided is unsustainable and needs to be re-assessed urgently, before rationing becomes a crisis of necessity rather than of choice [22]. How might countries reduce the environmental impact of specific healthcare interventions? Fractional taxation of the estimated financial cost of an intervention might enable redistributive investment in sustainability and should be relatively straightforward to administer. More specific national initiatives (e.g. Getting it Right First Time [19], Choosing Wisely [23] and the Intercollegiate Green Theatre Checklist [24]) invite healthcare systems to think about reducing financial, and therefore environmental costs but may have limited global applicability. Regardless of their shortcomings, it is inevitable that unpopular ways of reducing the environmental impact of healthcare by limiting its supply will need to be debated soon, e.g. re-evaluating ‘futility’ and ‘success’ thresholds; repeated procedures; value (numbers needed to treat); and the utility of routine investigations. Greater environmental benefits would accrue from radically reducing the demand for clinical services, and more acceptably than rationing their supply. Currently, models of healthcare provided in high-income countries are necessarily ‘disease-care’ models, which react very successfully to acute clinical problems but have proven far less effective at preventing chronic ill health. New paradigms are needed to interrupt the common pathways of chronic disease, reducing the need for future clinical treatment and therefore the financial costs and environmental impacts of medicine [25]. In practice, this might involve motivated anaesthetists broadening the scope of pre- and postoperative assessment clinics towards preventative/non-operative management or retraining to become specialists in preventative medicine/public health or adopting health management/political roles. Manmade climate change is accelerating towards the collapse of human civilisation within a plausible and palpable 30-year time horizon. Humanity has too few years – six – to avert this climate endgame without radically reducing carbon dioxide emissions. Even at this late stage, existential pessimism can be defeated by collective personal, professional and societal change if all of us do all that we can all of the time. The alternative – an ‘unliveable future’ – is unthinkable. The views expressed are those of the authors. SW was convenor of the World Federation of Societies of Anesthesiologists consensus principles of environmentally sustainable anaesthesia. HM has received a grant from the Oak Foundation to support health service decarbonisation and is partly funded by the UK NIHR Comprehensive Biomedical Research Centre at University College Hospitals, London. The authors encourage readers to watch this video to learn more about the views expressed in this editorial https://www.youtube.com/watch?v=i2a-6KCAuKs&list=PL3DB2dmXdc7aKdVmseHqW2tlhV2hdrGbo&index=4&pp=gAQBiAQB. No external funding or other competing interests declared. Figure S1. The green anaesthesia manifesto. 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