Rethinking carbon footprints

By focusing public attention on individual choices, your commute, your cup of coffee, your weekend city break, the 'carbon footprint' campaign diverted scrutiny from the systemic scale of fossil fuel extraction and combustion

Dr Michelle McKeown: "In 2004, BP (formerly British Petroleum) amplified the term through a glossy marketing campaign centred around an online 'carbon footprint calculator'. Suddenly, climate responsibility had a personal, almost confessional dimension. You, dear consumer, were being asked, how guilty are you? It was a masterstroke of corporate sleight of hand."

When was the last time you thought about your carbon footprint? Chances are it was while hovering over a recycling bin, agonising about whether a greasy pizza box belonged in the 'compost waste', 'recycled waste', or 'general waste'. The term has seeped so deeply into our collective vocabulary that it’s hard to imagine a world without it. But here’s the thing, the concept of the carbon footprint, far from being a grassroots tool of eco-activists, was popularised by the very industry most responsible for pumping carbon into the atmosphere... Big Oil.

A footnote on origins

The phrase 'carbon footprint' gained traction in the early 2000s, building on the 'ecological footprint' concept coined in the 1990s by Canadian ecologist William Rees and his student Mathis Wackernagel. They wanted to capture how much land and sea area is required to support human consumption and waste.

In 2004, BP (formerly British Petroleum) amplified the term through a glossy marketing campaign centred around an online 'carbon footprint calculator'. Suddenly, climate responsibility had a personal, almost confessional dimension. You, dear consumer, were being asked, how guilty are you?

It was a masterstroke of corporate sleight of hand. By focusing public attention on individual choices, your commute, your cup of coffee, your weekend city break, the campaign diverted scrutiny from the systemic scale of fossil fuel extraction and combustion.

While the calculator empowered some of the track emissions, it risked overshadowing the need for industry accountability.

Imagine a cigarette company in the 1950s telling smokers to track their 'nicotine footprint' rather than asking whether tobacco companies should keep flooding the market with addictive products.

A matter of scale

Now, don’t get me wrong. Personal carbon footprints aren’t meaningless.

From a scientific standpoint, they provide a rough measure of greenhouse gas emissions tied to our everyday lives, typically expressed in tonnes of carbon dioxide equivalent (CO₂e) per year. The average Irish citizen’s footprint is around 11.6 -12.5 tonnes CO₂e annually, more than double the global average of 4.7 tonnes, and far higher than the 2.5 tonnes per person per year scientists say we’d need to hit by 2030 to limit warming to 1.5°C.

Your footprint isn’t just about car trips and electricity bills. Consider food. Producing a kilo of beef generates around 50–70 kg of CO₂e, depending on production methods, while lentils contribute less than 1 kg. That latte in your hand? Roughly 0.55 kg CO₂e if it’s made with cow’s milk, but around 0.25 kg with oat milk. Multiply that by your daily habits and you quickly see how diet can balloon footprints.

Flying is another notorious culprit: a return flight from Dublin to New York emits around 1.6 tonnes CO₂e per passenger — roughly the same as driving an average car for six months.

These numbers matter. They help us understand the weight of seemingly small decisions. But they also expose the scale of the challenge. No amount of virtuous oat lattes can offset the impact of a long-haul holiday or a poorly insulated home.

Who wears the biggest boots?

Here’s the kicker, per the 2017 Carbon Majors Report, 100 companies, including fossil fuel giants such as ExxonMobil and Shell, are responsible for 71% of global industrial greenhouse gas emissions since 1988, counting both direct operations and product use. So, while we tally up our reusable shopping bags and argue over compost bins, systemic forces (energy grids, agricultural policy, industrial supply chains) continue to drive the climate crisis.

This doesn’t mean personal action is pointless. Rather, it’s about perspective. Think of footprints like ripples, where one step creates an effect, but collective movement creates a wave.

Recycling and going vegan won’t single-handedly save the planet, but they help normalise climate-conscious behaviour, push markets towards sustainable products, and, perhaps most importantly, signal to policymakers that people are ready for systemic change.

A shoe size thought experiment

Imagine if your carbon footprint could be visualised as actual shoes. The average footprint in the US (around 16 tonnes per person) might resemble a pair of oversized clown shoes.

The global average? Perhaps a sturdy hiking boot. And the 2.5 tonnes scientists recommend for a stable climate? More like minimalist sandals.

Meanwhile, many in the emerging and developing countries live within this target but face disproportionate climate impacts, like rising sea levels or extreme weather. The point is that most of us in developed countries are stomping around like Bigfoot when the climate budget requires us to tiptoe.

But here’s the uncomfortable truth, even the most virtuous eco-warriors struggle to live within the 2.5-tonne target while operating in a fossil-fuelled system. Individual footprints can’t be shrunk to sandal-size without structural support. Think renewable energy grids, carbon pricing, rewilded landscapes, and serious investment in public transport.

Putting the boots on the right feet

So, next time someone asks about your carbon footprint, feel free to answer with a question of your own... And what’s the footprint of your pension fund, your local council, or the company you buy energy from?

Climate action isn’t about shaming individuals for enjoying hot showers or the occasional flight. It’s about recognising that footprints are a tool to understand our role, not a moral measuring stick. They empower us to make informed choices, but their origins remind us to question who’s framing the conversation.

If anything, the lesson of the carbon footprint is not how small we can make ourselves, but how large we can act together. One person reducing their footprint is like a single bootprint in wet sand that is easily washed away. But millions moving in the same direction? That’s how you leave a mark.

• Dr Michelle McKeown is an environmental geographer and lecturer at University College Cork. Her research spans climate change impacts, carbon cycling, and ecosystem integrity, with a strong focus on both modern and palaeo-environmental systems in mid-latitude and tropical regions. She works on interdisciplinary projects to understand long-term climate dynamics and freshwater ecosystem responses across time.