Global efforts to mitigate climate change have traditionally focused on the manufacturing and energy sectors. However, recent research increasingly highlights the key role of demand a household consumption at achieving global climate goals. It turns out that supply-side measures alone may not be enough.

Two-thirds of emissions originate from consumption

According to available sources Household consumption directly and indirectly triggers approximately two-thirds of total greenhouse gas (GHG) emissions. This figure includes all emissions generated within complex global supply chains. This means that the decisions we make in our daily lives – what we buy, how we travel, what we eat – have a huge impact on the planet’s overall carbon footprint. Shifting household consumption patterns towards low-carbon regimes is therefore a critical part of climate change mitigation.

Carbon inequality and responsibility

It is important to remember that emissions associated with consumption are not distributed evenly. The concept carbon inequality shows that a relatively small, wealthy portion of the global population largely drives consumption-based emissionsFor example, the top 10 % issuers accounted for 48 % of global issuance in 2019, while the bottom 50 % only accounted for 12 %.

The study therefore primarily focuses on top 23.7% issuers of the world's population (approximately 1.6 billion people) who exceed the global annual target (4.6 t CO2e per capita in 2020 to limit warming to below 2 degrees). These people not only have the largest carbon footprint, but also the greatest capacity to reduce emissionsThe majority of these households live in high- and upper-middle-income countries (89.0%), but significant contributors to high-consumption emissions are also found in emerging economies.

Potential for massive reduction

A simulation of low-carbon spending measures (such as using cars less, flying less, working from home, a healthy vegan diet, energy-efficient housing, sharing and repairing appliances, fewer commercial services) among these top 23.7% emitters showed significant reduction potentialImplementing a combination of 21 such low-carbon measures could lead to a global carbon footprint reduction of 10.4 gigatons of CO2eThis represents 40.1% of household emissions in the 116 countries analyzed or 31.7% of total global household carbon footprint in 2017.

The greatest reduction potential was identified in the categories mobility (11.8% of the total reduction), services (10.2%) and food/diet (8.2%). Avoidance measures – e.g., travel less – often show higher emission mitigation potential than shift or improve measures. Regions such as North America and Europe and Central Asia show high relative reduction potential.

Unforeseen Challenge: Rebound Effect

Although the potential is significant, the path to low-carbon lifestyles is not without obstacles. The most significant unintended consequence is the so-called reflection effectThis occurs when money saved or time thanks to low-carbon measures (e.g. reducing energy consumption, traveling less) spend on other products or services.

The study focused mainly on indirect reflection effects – that is, redirecting the money saved to the consumption of other goods and services, leading to increased emissions in the supply chains of these other products. It is estimated that these indirect spillover effects can compensate 6.5% to 45.8% of expected global carbon reduction. In absolute terms, this represents a loss of carbon savings of the order of 0.7 to 4.8 Gt CO2e.

The magnitude of the rebound effect depends on how the saved money is spent. Scenarios where it is spent on common, unaffected items (SC1) showed the highest rebound effect (45.8%). The scenario where the saved money is purposefully spent on the least carbon-intensive items (SC3) showed the lowest rebound (6.5%).

It has been shown that measures related to services (e.g. fewer leisure activities) tend to have larger “backfire effects” because the money saved is often redirected to areas with higher carbon intensity, such as increased food consumption or longer time spent at home (increasing energy consumption in households). Controlling the reflection effect is therefore fundamental to maximize net emissions savings.

Implementation complexity and the issue of equality

The transition to a low-carbon lifestyle is complex, as individual decisions are closely linked to income levels, willingness, resource availability and existing policy and fiscal frameworks. Effective implementation requires a combination of regulatory, economic and information tools, not relying on one tool.

It is also necessary to take into account equality and justiceMeasures applied uniformly to entire populations can disproportionately affect vulnerable groups, especially those that already have low living standards. Policies should therefore be differentiated:

• For high-income groups, the focus should be on limiting the consumption of luxury goods with a high carbon footprint, for example, through progressive taxation.
• In lower-income regions and for low-income groups, priority should be given to better access to affordable and sustainable options instead of limiting consumption. The aim is to ensure that low-carbon changes do not exacerbate existing inequalities.

Linking demand and supply

To achieve meaningful and widespread adoption of low-carbon lifestyles, policies they must also address the production/supply sideIt is crucial to ensure that they are sustainable options widely available and affordable, because consumer decisions are strongly influenced by what is available and accessible. Demand-side (lifestyles) and supply-side (technology) measures interact with each other complementLifestyle changes can provide "breathing space" for the deployment of long-term technological solutions.

Although low-carbon lifestyles represent significant and relatively fast potential for mitigating emissions, their implementation faces significant challenges. The biggest one is reflection effectwhich can substantially reduce net emission savingsEffective strategies must take into account consumer behavior, active mitigate reflection effects (e.g. by directing spending towards low-carbon products), address inequalities and ensure availability of sustainable options on the supply side. Only in this way can the real contribution of changes in household consumption to the fight against climate change be maximized. Spring