Eco-sufficiency

Ecological sufficiency, or simply sufficiency, refers to the concept or strategy to reduce the environmental footprint of societies through moderating the need for energy, carbon and material based services and products. The term was popularised by authors such as Thomas Princen, a professor at MIT, in his 2005 book The Logic of Sufficiency. As a goal, sufficiency is about ensuring that all humans can live a good life within planetary boundaries, meaning without overshooting the ecological limits of the Earth and thus limiting resource use and pollution. Princen argues that "seeking enough when more is possible is both intuitive and rational – personally, organizationally and ecologically. And under global ecological constraint, it is ethical." In order to operationalise sufficiency, principles and ideas of concrete actions and policies have been proposed by various authors. Sufficiency may be approached at the individual level as a personal attitude or life philosophy (such as in the Sobriété heureuse concept of French environmentalist Pierre Rabhi,

As an increasing number of experts consider that technical progress and greener technologies alone will not be enough to achieve this goal, sufficiency also designates the societal transformations (in terms of lifestyles, social practices, infrastructures, etc.) that will be necessary to bring production and consumption patterns to a level compatible with the goal. It raises the question of individual and social limitations on these current patterns, building in particular on a sense of "enoughness". The IPCC defines sufficiency as "a set of policy measures and daily practices that avoid the demand for energy, materials, land, water, and other natural resources while providing wellbeing for all within the planetary boundaries". The term sufficiency has been popularised by Thomas Princen's book The Logic of Sufficiency published in 2005, in which he argues that "seeking enough when more is possible is both intuitive and rational – personally, organizationally and ecologically. And under global ecological constraint, it is ethical." Sufficiency may be approached at individual level as a personal attitude or life philosophy (such as in the Sobriété heureuse concept of French environmentalist Pierre Rabhi, or Schneidewind's concept of the 'Good Life'), as well as a core collective value that could amend the notion of liberal societies. Sufficiency can be interpreted and discussed in virtually all social settings and economic sectors. In terms of lifestyles, it is strongly related to the concepts of voluntary simplicity and downshifting.

The concept of sufficiency has been primarily developed in the area of energy consumption, where levels of greenhouse gas emissions far exceed what the planet may absorb and "rapid, far reaching and unprecedented changes in all aspects of society" are necessary according to IPCC. Drawing on the limits of technical efficiency and rebound effects, sufficiency proponents argue that energy demand and its associated emissions cannot be sufficiently reduced if the root causes of this demand are not addressed, that is the nature and level of the energy services our societies rely on. In that prospect, energy sufficiency is about questioning and reducing energy demand through "changes in quantity or quality" of the energy based services consumed, notably by "favouring behaviours and activities that are intrinsically low on energy use". The boundary between efficiency and sufficiency actions are not always precisely set; some authors have a broad conception of efficiency that may include aspects of lifestyle change. Academic work released in 2022 systematically classified and databased specific public policy measures that can, individually and collectively, contribute to the uptake energy sufficiency.

Sufficiency is also applicable to material consumption. Similar to energy sufficiency, it consists in reducing demand for services and activities requiring high level of material resources, and favouring intrinsically lean ones. It is for instance associated with the ideas of avoiding wasteful consumption, owning fewer products, and prolonging their lifetimes. Here also, depending on authors' definitions, the boundary between efficiency and sufficiency may not always be perfectly drawn. As an illustration, a report for UNEP classifies items such as reducing living spaces, driving smaller cars and car sharing as material efficiency, while they would be more traditionally viewed as sufficiency.

Sufficiency largely remains a blindspot in most established ecological/energy transition scenarios, where efficiency and greener technologies are the main and only strategies usually modelled. There are exceptions though. The French négaWatt Association has assessed the potential of energy sufficiency at the level of France, through its national négaWatt 2050 scenario. The scenario is based on three principles (sufficiency efficiency renewables) with the goal of reaching a factor 2 reduction on energy demand and factor 4 on greenhouse gas emissions by 2050, involving changes in lifestyles and societal organisation considered as reasonable by the modellers. Sufficiency appears to be able to provide more final energy savings than efficiency. A German study found that sufficiency measures could lead to a theoretical reduction of 70% of energy consumption at the level of households. The calculation assumes sufficiency measures encompassing the size of appliances (smaller, fewer appliances) as well as in their usage patterns. A number of other scenarios and models lead to similar conclusions on the magnitude of saving potentials. In order to encourage and improve the robustness and visibility of sufficiency modelling in energy scenarios, guidelines and recommendations have been published e. g. by the Ministry of Environment in Germany, or the SHIFT Project in France).

As it builds on a sense of self and collective moderation in relation to the consumption of energy and material based services, sufficiency requires drawing a line between wants seen as superfluous and actual justified needs. It triggers potentially complex and contentious theoretical and practical questions. Answers may differ culturally, change with time and context, as well as depend on income and other socio economic factors. The issue is not only relevant at the level of individual values, ethics, and lifestyles, but also for public decisions. As an illustration, whereas building or extending an airport was rarely challenged successfully in the past, two recent decisions show this has changed: the decision of the French government to drop the Notre Dame des Landes airport in 2018, and the UK court decision to rule Heathrow's extension illegal over climate change in 2020.

Sufficiency supposes a moderation in the consumption and development of high energy based and material based services, which are often delivered by or associated with goods and equipment. Thus, sufficiency means limitations on current consumption levels of some products and renouncing some types of infrastructures. A common criticism, shared with the degrowth concept, is that this would hurt economic growth, increase unemployment and lead to social problems. While it is clear that current energy and resource intensive services would be hit by sufficiency, leaner, more local, and employment intensive activities would also be fostered in the meantime. There is currently limited research on the macroeconomic impacts of a sufficiency based society. Notably, there is a lack of understanding of how systematic sufficiency based business models could be developed and promoted, and how it would change the economic system.

A third objection to sufficiency is that, as for efficiency, the energy and material savings could lead to indirect rebound effects. This suggests that sufficiency should be implemented as comprehensively as possible, to avoid savings in one sector being annihilated by the growing environmental footprint of another. Capping incomes and resource use are strategies that could mitigate rebound effects.