How do we decarbonise fairly? Emissions,inequities and the implications for net zero healthcare

Since the ‘Greener NHS’ ¹ strategy for a net zero health service was launched in October 2020, attention has shifted from awareness raising to supporting and accelerating its implementation. ² There are opportunities to improve health on the pathway to net zero, as well as challenges; among them, inequality in healthcare needs and emissions merits closer attention.

Climate change as a moral problem addresses such inequalities. Temperature rise is caused by the greenhouse gas emissions from predominantly high-income countries, while climate change hits people hardest in low- and middle-income countries. Healthcare is, in this regard, the rule rather than the exception. Unmet healthcare needs are greatest in low-income countries while healthcare emissions are 70-fold higher in high-income countries, reflecting both more healthcare provision and low-value and unnecessary care. ³

Such inequalities between countries capture the challenges of realising ‘international justice’ which underpin the attempts of the Paris Agreement, the legally binding international climate treaty, to allocate national responsibilities for cutting emissions and compensate for climate adaptation. ⁴ The Paris Agreement does not, however, state who should bear the costs within countries for the policy measures required to reach net zero, an issue especially pertinent for healthcare’s decarbonisation. As we will see, this creates concerns calling for what we can call ‘intranational justice’.

Within England there are large socioeconomic inequalities in income, life opportunities and educational attainment, and a widening health gap between the richest and most deprived areas of the country. ⁵ People who are more deprived have worse healthcare outcomes, spending over twice as long in ill health than the least deprived, with three to four times higher levels of avoidable mortality amenable to healthcare and public health interventions. ⁵ There is widespread public, political and philosophical agreement that this is unfair. As a consequence of poor health, people who are more deprived also consume a greater amount of health services, as illustrated in Figure 1, both in terms of healthcare spending and service utilisation in primary^6,7 and secondary care. ⁸ Given healthcare consumption is the ultimate driver of healthcare emissions, this has important implications in terms of justice for the pursuit of net zero healthcare.

Figure 1.

Social gradient in healthcare utilisation, England, 2018–2019. (Source of data: NHS Digital ⁹ .) Note: Relative rate compared to decile 10 (least deprived); Index of multiple deprivation scale used here is the English indices of deprivation; critical care data are from 2014–2015.

Rates of healthcare utilisation, presented in Figure 1, also overlook other inequalities: needs-adjusted healthcare utilisation is lowest among the most deprived, while risk factor-adjusted health outcomes are skewed towards the wealthy. Cookson et al. ¹⁰ characterise this as a ‘pro-poor distribution of quantity but a pro-rich distribution of quality’. Although perversely offset by a lower life expectancy, lifetime healthcare costs are still 10%–20% higher among the most deprived quintile as compared to the least deprived quintile. It seems likely that individual healthcare carbon footprints also follow a social gradient, with emissions highest among the worst-off.

This is potentially important for the net zero agenda which, in part, involves transforming how the NHS delivers care and changing behaviour of individuals.^11,12 Without careful consideration, the reallocation of resources affecting the provision or healthcare can, unintentionally, target the poor and risks exacerbating existing unfair health inequalities.

In the United Kingdom, emissions by income decile vary from 3 to 28 tonnes of carbon dioxide equivalents. ¹³ Emissions of the richest 10% of the population are equivalent to the total emissions of the poorest 50%. This inequality is illustrated clearly when the healthcare carbon footprint – 0.54 tonnes per capita in England ¹⁴ – is calculated as a proportion of the per-capita footprint (Figure 2).

Figure 2.

Healthcare carbon footprint as a proportion of total per-capita footprint, by income decile. (Source of data: Per-capita healthcare footprint from Tennison et al. ¹⁴ – a detailed analysis of the English NHS carbon footprint; Per-capita carbon footprint from the World Inequality Report database ¹³ – the most comprehensive database on wealth and income inequality. Note: In line with the healthcare carbon footprint, we compare with individual’s total emissions using consumption-based emissions accounting.)

Whereas healthcare carbon emissions represent almost one-fifth of the per-capita footprint in the poorest decile, it follows a social gradient and is under a fiftieth in the richest decile. Due to the variation in healthcare consumption across income deciles (see Figure 1) this difference is likely to be substantially higher, representing perhaps around one-quarter of the carbon footprint among the worst off. The NHS in England has committed to ambitious net-zero targets – an 80% reduction in emissions under its direct control by 2028–2032 and across the supply chain by 2036–2039, reaching net zero by 2040 and 2045, respectively. How can costs and burdens be equitably distributed along the way?

Emissions must all ultimately reach zero, but a fair pathway will also minimise forgone health gains. A pressing issue that merits ongoing discussion is whether those with the greatest means and total emissions caused outside the healthcare system should also shoulder the greatest responsibility to reduce their carbon footprint. For example, a return flight from London to New York incurs four times the NHS’ per-capita carbon footprint or almost the annual total emissions of an individual in the poorest decile. The richest 20% of the UK population account for 70% of flights ¹⁵ ; yet, there remains little political appetite for a frequent flyer levy that can both substantially cut emissions and enhance equity. The difference between healthcare and aviation emissions reflects a distinction drawn by philosopher Henry Shue between subsistence emissions – those necessary to secure basic subsistence, which should not be sacrificed – and luxury emissions – those exceeding this level, which should. ¹⁶ Although developed to conceptualise international responsibilities, this idea applies at the national level too. ¹⁷

To reduce carbon emissions within the healthcare system there are at least three primary means to incorporate emission reductions. The first, which we have discussed elsewhere, ³ is to value carbon emission reductions alongside measures such as cost-effectiveness, health maximisation and inequality aversion, within existing approaches to resource allocation. The second is to consider emissions as a constraint; aiming to maximise the desired outcomes (i.e. financial spending, health gains, reducing health inequalities) within a fixed ‘carbon budget’, in a similar way to financial budgeting. The third is to aim for as low emission as possible on all activities within the healthcare system, while minimising forgone health gains. Pursuing any option explicitly or implicitly involves trade-offs since a re-allocation of resources may displace spending from more cost-effective interventions. Policy makers and staff have shown a strong commitment to the Greener NHS initiative. ¹⁸ Given the rapidly closing window to avert catastrophic levels of climate change, this may well be a priority for patients too.

In July 2021, the Health Foundation surveyed public perceptions of the NHS net zero plan. ¹⁹ Although over 8 in 10 people had not heard of Greener NHS and net zero was far down the public’s priority list for the NHS, most respondents supported the net zero ambition (only 6% opposed), stating that the NHS should reach net zero at least as quickly as other sectors. There are some important differences across income groups. While the most deprived and least deprived quintiles shared a high willingness to make lifestyle changes to help tackle climate change (72% vs. 78%), they differed regarding the responsibility of the NHS to reduce its climate impact (37% vs. 53%). Similarly, support among the most deprived quintile was lower for disease prevention if this might involve decreased hospital funding (48% vs. 57%) and the receiving one medicine over another because of its environmental impact (61% vs. 74%). These numbers might suggest that some among those who depend on the public healthcare system, and who risk the most if health gains are foregone due to already existing health inequity, find it doubly unfair to carry the burden of reducing carbon emission.

The pandemic has shown that people are willing to make sacrifices. Crucially, when clearly communicated, and financially and socially supported to do so, people can undergo transformational changes in how they live, work and even breathe. As with pandemic measures, the burdens of climate impacts and cutting emissions are not equally shared. Since the government’s net zero ambitions are enshrined in national and international law, the targets themselves are non-negotiable; however, which sectors lead and who bears the costs and burdens of decarbonisation is contingent on the choices made along the way. Our response must account for the existing inequities in the world, encompassing both inter- and intranational justice.