Carbon footprint calculators hold significant promise for encouraging sustainable behaviours, saving money, and enabling environmentally conscious decisions. By translating the impact of everyday purchases into measurable data, often represented as CO2e (carbon dioxide equivalent), these tools aim to make environmental impacts tangible. However, despite their potential, many consumers find them confusing, overwhelming, or unrelatable.
What is my impact on the planet?
1. Understanding Carbon Impact: What is CO2e?
One of the most significant barriers to adopting carbon footprint calculators is understanding CO2e—the unit that quantifies greenhouse gas emissions by converting them into a standard measure based on their global warming potential. While scientifically robust, this metric is often too abstract for the average user, creating a disconnect from its real-world significance.
For instance, being told your morning coffee generates 0.3–0.5kg of CO2e might sound precise, but without relatable context, it’s difficult to interpret. To make sense of it, users need comparisons. However, comparisons are not always relevant or representative. For instance 0.5kg of CO2e is roughly equivalent to driving 1.25 miles in a petrol car or powering a 60-watt light bulb for 8 hours [1]. Such metrics, though precise and informative, fail to engage users as they lack a relatable framing or a relevant benchmark. Without telling consumers what this impact means and what to do about it, they eventually will be left wondering.
This lack of clarity is pervasive—75% of consumers report struggling to interpret environmental data [2]. In addition, a study by the European Environmental Agency found that 28% of consumers cite unclear labelling as a significant barrier to making sustainable purchases [3]. To bridge the gap between information about impact and action requires relatable terms and a clear scale.
How Does CO2e Translate into Money?
2. Linking Carbon Impact to Spending: How Much Money?
Even when users understand the concept of CO2e, connecting it to everyday purchases remains a challenge. Understanding the carbon footprint of what we buy, where we shop, and how we consume is essential for making informed, sustainable decisions. However, current tools often fail to provide the detailed clarity required to empower such choices effectively.
Take a weekly grocery shopping that generates 50kg of CO2e. Standing alone this figure is abstract and unhelpful because without a breakdown of the emissions—whether they come from food, packaging, or transportation—it’s nearly impossible to know which behaviours to adjust. Moreover, this same amount of emissions could have been caused by a purchase of £35 or by a purchase of £100, depending on the contents of the shopping basket. For instance:
- Beef has an average carbon footprint of 100kg of CO2e per kilogram
- Plant-based proteins like peas or tofu produce just 0.5–3kg of CO2e [4].
Likewise, within plant-based foods, environmental impacts can vary. Shipping 1kg of avocados from Mexico to the UK generates 0.21kg of CO2e from transport alone, accounting for about 8% of their total footprint. Almonds, while low in CO2e emissions, demand large quantities of water during cultivation, complicating their overall environmental impact [5].
This stark difference shows both the significant role that dietary choices play in emissions and how our shopping basket can lead to vastly different carbon footprints. Without clarity, users might feel that their efforts making environmentally friendly choices are misguided or too complex, creating frustration and preventing meaningful behavioural change.
How Much CO2e is Too Much or Too Little?
3. The Context of Emissions: When Is It Too Much?
One of the biggest challenges with carbon footprint calculators is understanding whether your carbon footprint is “good” or “bad”. To determine this, a benchmark is necessary. Benchmarks—comparisons to a standard, average, or estimate—are essential for providing context, but most calculators fall short in offering clear or meaningful comparisons.
For instance, being told that your annual CO2e emissions are 10 tonnes doesn’t help unless you understand what that number represents. Is it better or worse than the emissions you’re supposed to cause? Does it align with climate goals? If so, which climate standard serves as the right benchmark?
For example, should benchmarks be based on average emissions for a city, country, continent, or globally? The average CO2e emissions per person in the US is around 14.3 tonnes annually, compared to 4.4 tonnes in the UK or 4.7 tonnes globally [6]. Such variations can confuse users, especially when their emissions differ significantly from one country to another. Another benchmark to consider is the Paris Agreement’s target of limiting global warming to 1.5°C, which requires reducing annual emissions to 2 tonnes per person by 2050 [7].
These disparities highlight the challenge of setting meaningful benchmarks that are both realistic and globally equitable. Local or national averages (realistic benchmark) may motivate users to compare themselves to their peers. However, a rebound effect can occur: users with below-average emissions may feel they’ve already done enough and stop striving for further reductions. Targets like the Paris Agreement’s 2-tonne goal (aspirational benchmark) aim to inspire collective action. However, these ambitious objectives often feel out of reach, particularly because developed countries’ emissions are frequently over five times this limit. The gap leaves users feeling that their individual efforts are insignificant; no matter what they do, the bar is too high.
A study by the UN’s Emissions Gap Report states that global emissions must drop by 7.6% annually from 2020 to 2030 to align with the 1.5°C target [8]. Yet, most current policies project a global temperature rise of 2.4–2.8°C by the end of the century [9], illustrating how far aspirational goals are from present realities.
The disparities in emissions across income groups exacerbate these challenges [10]:
- The wealthiest 1% emit 30 times more CO2e than the 1.5°C target.
- The poorest 50%, however, emit less than half the per capita allowance.
These inequities can foster a sense of futility among average consumers, who may feel their efforts are overshadowed by the excessive emissions of a small, affluent group. Addressing these perceptions requires meaningful benchmarks that are both equitable and actionable.
Even If We Take Action, How Can I See My Progress?
4. Too Much Effort: Why Can’t I See My Impact?
A particularly frustrating challenge for users is when significant lifestyle changes result in only small carbon savings. For instance, a family switching to reusable shopping bags might reduce their carbon footprint. While this is a positive change, it pales in comparison to emissions from other activities, like commuting or energy use, which can still generate hundreds of kilograms of CO2e.
Similarly, adopting energy-efficient appliances at home might save emissions over the long term, but users may not see immediate results on their carbon footprint calculators, leading to demotivation.
A clear example involves electric vehicles (EVs), they are widely recognised for their energy efficiency and low operational emissions. However, their environmental benefits depend on long-term usage due to their high production emissions. Manufacturing EV batteries significantly increases their initial carbon footprint compared to conventional gasoline cars.
The production of a medium-sized EV generates 14–16 metric tonnes of CO2e (including battery and vehicle manufacturing), compared to 8–10 metric tonnes for a gasoline car [11]. The large lithium-ion batteries used to power EVs contribute 40–60% of the total production emissions, largely due to the resource-intensive process of mining and producing the batteries [12]. As a result, the production footprint of an EV is roughly double that of a typical internal combustion engine vehicle [12].
Due to these initial differences, it typically takes 1.4 to 2 years (approximately 20,000 miles or 32,000 km) of driving for an EV to offset its higher production emissions compared to a gasoline car [13, 14]. After this point, EVs continue to outperform gasoline cars in terms of emissions savings over their lifetime.
A Path Forward
The impact of carbon footprints needs to take into account both the pros and cons of purchases, as well as the lifetime changes associated with them. Consumers must have a clear understanding of carbon footprint emissions and how they translate into their finances, daily habits, and their broader impact on the planet. At Behavioural Finance Consulting, we know that to drive real behavioural change, people should be presented with actionable benchmarks that allow them to track their progress and feel motivated to act.
To truly connect carbon impact with consumer purchases, carbon footprint calculators must move beyond abstract figures and offer actionable, relatable insights. By breaking down emissions, integrating financial data, and providing clear rewards for change, these tools can empower users to make meaningful progress. With the right tools, consumers can understand how even small steps lead to significant impacts—both for their wallets and the planet.
The challenge becomes even greater when progress is slow or imperceptible. Sustainable behaviour often mirrors the experience of a diet or a gym routine: results typically emerge only in the mid- to long-term. Just as it takes months of exercise to see meaningful physical changes, adopting eco-friendly habits like using renewable energy or reducing car usage can feel like an uphill battle with delayed gratification.
Even when consumers achieve tangible results, maintaining progress is no easy task. Studies show that up to 80% of people revert to old habits after initial success in areas like weight loss or fitness—and sustainable behaviour is no different. For instance, more than half of people who lost weight on a diet regained it within two years, and after five years, more than 80% of lost weight was regained [15]. Without regular reinforcement or visible rewards, people often slide back into previous behaviours, such as choosing convenience over sustainability or regaining weight after a successful diet.
Breaking old habits and sticking to sustainable behaviours requires more than simply presenting CO2e data and promoting good intentions. Sustainability, like any long-term commitment, is a journey. Ensuring that users see the impact of their efforts—both individually and collectively—is the key to keeping them on track and at Behavioural Finance Consulting we have the solution to bring about that change.
References
[1] My Climate, Calculate and support (https://co2.myclimate.org/en/calculate_emissions).
[2] Bain & Company, “Selling Sustainability Means Decoding Consumers” (https://www.bain.com/insights/selling-sustainability-means-decoding-consumers-ceo-sustainability-guide-2023/).
[3] Euromonitor International, “Megatrends: Understanding Sustainable Consumers 2023 Key Insights” (https://www.euromonitor.com/article/megatrends-understanding-sustainable-consumers-2023-key-insights).
[4] Our World in Data, “The carbon footprint of foods: are differences explained by the impacts of methane?” (https://ourworldindata.org/carbon-footprint-food-methane).
[5] Our World in Data, “You want to reduce the carbon footprint of your food? Focus on what you eat, not whether your food is local” (https://ourworldindata.org/food-choice-vs-eating-local).
[6] Our World in Data, “Per capita CO₂ emissions” (https://ourworldindata.org/grapher/co-emissions-per-capita).
[7] Our World in Data, “How much CO2 can the world emit while keeping warming below 1.5°C and 2°C?” (https://ourworldindata.org/how-much-co2-can-the-world-emit-while-keeping-warming-below-15c-and-2c).
[8] United Nations Climate Change (UNCC), “Cut Global Emissions by 7.6 Percent Every Year for Next Decade to Meet 1.5°C Paris Target – UN Report” (https://unfccc.int/news/cut-global-emissions-by-76-percent-every-year-for-next-decade-to-meet-15degc-paris-target-un-report).
[9] UN Environment Programme (UNEP), “Emissions Gap Report 2024” (https://www.unep.org/resources/emissions-gap-report-2024).
[10] Oxfam, “Carbon inequality in 2030” (https://www.oxfam.org/en/research/carbon-inequality-2030).
[11] Visual Capitalist, “Life Cycle Emissions: EVs vs. Combustion Engine Vehicles” (https://www.visualcapitalist.com/life-cycle-emissions-evs-vs-combustion-engine-vehicles/).
[12] McKinsey & Company, “The race to decarbonize electric-vehicle batteries” (https://www.mckinsey.com/industries/automotive-and-assembly/our-insights/the-race-to-decarbonize-electric-vehicle-batteries).
[13] Fact Check, “Electric Vehicles Contribute Fewer Emissions Than Gasoline-Powered Cars Over Their Lifetimes” (https://www.factcheck.org/2024/02/electric-vehicles-contribute-fewer-emissions-than-gasoline-powered-cars-over-their-lifetimes/).
[14] Kelly, Jarod C., et al. “Cradle-to-Grave Lifecycle Analysis of U.S. Light-Duty Vehicle-Fuel Pathways: A Greenhouse Gas Emissions and Economic Assessment of Current (2020) and Future (2030-2035) Technologies”, Nov. 2023. https://doi.org/10.2172/2228291.
[15] Hall KD, Kahan S. “Maintenance of Lost Weight and Long-Term Management of Obesity”. Med Clin North Am. 2018 Jan;102(1):183-197. doi: 10.1016/j.mcna.2017.08.012. PMID: 29156185; PMCID: PMC5764193.