Supply-side measures alone are not enough to achieve global climate goals. The growing importance of demand-side solutionsFrom a consumption perspective, taking into account all emissions in supply chains, household consumption is directly and indirectly responsible for approximately two-thirds of total greenhouse gas (GHG) emissions. Therefore, transition to low-carbon consumption patterns a key part of climate change mitigation.

The literature on carbon inequality highlights the importance of equitable demand-side measures. Tackling climate change requires a multi-pronged approach that includes reducing emissions from high emitters while supporting those who face barriers to the transition to low-carbon living, such as energy poverty. Studies have found that in 2019, the richest households are the main contributors to consumption-related emissions. For example, 23.7 % of the world’s population exceeds the global average per capita emissions needed to keep global warming below 2 degrees. These households account for approximately 78.1 % of global spending and contribute 63.7 % to consumption-related emissions in the 116 countries analyzed. This underscores the urgent need to target demand-side measures specifically at the carbon-intensive activities of these top emitters, as they have contributed the most to climate change and have the greatest capacity to reduce emissions. Resources indicate that high emitters come from all regions of the world, not just high-income countries.

To achieve demand-side mitigation, it is essential to adopt a low-carbon lifestyle that minimizes greenhouse gas emissions. The study quantified the greenhouse gas emission reduction potential using 21 low-carbon expensesThese expenditures include changes in direct energy consumption, household consumption, and indirect industrial inputs.

The analysis identified household carbon footprint hotspots in different consumption categories, with higher spending translating into higher carbon footprints globally. Spending on buildings and food tend to be the biggest contributors to emissionsWealthier households have a larger share of emissions from services and mobility.

The implementation of 21 low-carbon expenditures alone shows significant potential to reduce emissions. Measures with high potential include reducing the use of commercial services (up to 10.9 %), switching to healthy vegan diet (8.3 % reduction). Implementing passive house standards could lead to a 6.0 % reduction. In the area of mobility, switching from private cars to public transport, working from home and halving air travel could reduce emissions by 1.4–3.6 %. Avoid measures generally show the highest potential, followed by Shift strategies. The mitigation potential also varies between regions and countries.

When evaluating cumulative potential implementing these measures simultaneously, assuming their widespread adoption by households exceeding the carbon threshold, the study estimates global carbon footprint reduction of 10.4 gigatons of CO2e. This represents 40.1 % of consumption-based household emissions in the 116 countries analyzed, or 31.7 % of the global household carbon footprint in 2017. The largest reductions come from changes in spending on mobility (11.8 %), services (10.2 %) and food (8.2 %). Countries in North America, Europe and Central Asia, and Latin America and the Caribbean show significant relative mitigation potential. An interesting finding is unexpected demand-side potential in some sub-Saharan African countries, such as Mauritius, Namibia and Chad, which have often been overlooked in previous studies.

However, it is crucial to recognize that Emission savings are often offset by so-called rebound effects (rebound effect). These are unintended consequences when the money saved from adopting a low-carbon measure (e.g. reducing energy consumption) is spent on other products or services, which can lead to an increase in emissions in other areas. The study focused on indirect rebound effects among final consumers. Depending on the scenarios of re-spending of the saved money, the estimated indirect rebound effect ranges from 6.5 % to 45.8 % of expected global emission reductions. This effect could offset carbon savings of 0.7–4.8 gigatonnes of CO2e. The extent of the rebound effect varies depending on the patterns of re-spending. Emerging and developing economies are more likely to experience more significant “backfire” situations caused by such re-spending.

Implementing low-carbon lifestyle changes requires political support. A combination of regulatory, economic and information tools is generally more effective than relying on individual instruments. These policies should be tailored to different countries and income groups.

A low-carbon lifestyle can play a role a key role in short- and medium-term climate change mitigation effortsThese measures offer a quick and effective way to reduce emissions. To achieve meaningful and widespread adoption of low-carbon lifestyles, policies must also address the production side to ensure that sustainable options are widely available and affordable. Spring

The entire study was published in the journal nature.com

Glossary of key terms

• Low-emission lifestyles: Lifestyles and consumption patterns that lead to lower greenhouse gas emissions.
• Demand-driven solutions: Climate change mitigation measures that focus on changing consumption and consumer behavior.
• Global Multi-Regional Input-Output Model (MRIO): An economic model that tracks the flow of goods and services between different sectors and regions, allowing for the analysis of emissions along global supply chains.
• Carbon footprint: The total amount of greenhouse gas emissions caused by an individual, organization, product, or event. In this study, the focus is on household consumption.
• Consumption-based emissions: Greenhouse gas emissions that arise from the consumption of goods and services in a given region, including emissions produced elsewhere in the production and transportation of those goods and services.
• Carbon inequality: Uneven distribution of carbon emissions among different population groups, often related to income and consumption levels.
• The avoid-shift-improve framework: A holistic approach to low-emission lifestyle changes that includes absolute reduction in consumption (avoid), changing consumption patterns (shift), and improving efficiency (improve).
• Rebound effect: Unintended consequences, where savings (for example, money or energy) achieved by adopting more efficient or low-emission behavior are partially or fully offset by increased consumption of other goods or services.
• Indirect rebound effect: Rebound effect, where savings (for example, money) from one type of consumption leads to increased consumption of other goods and services in other sectors.
• Marginal expenditure shares: The proportion of additional spending incurred on a particular commodity for each dollar increase in total spending.