What Is Your Daily Carbon Budget?

Your daily carbon budget is the amount of CO2e (carbon dioxide equivalent) you can emit in a day while staying on track for a climate-safe year — commonly worked out as about 5.48 kg CO2e per day, based on dividing a 2-tonne annual target by 365 days. That 2-tonne figure is the per-person target widely cited as aligned with limiting global warming to 1.5°C, and it's the reference point used throughout this article.

Most people have never seen this number, let alone tracked against it. Annual emissions statistics are abstract — tonnes are hard to picture. A daily budget makes the same math tangible: it turns a distant climate target into a number you can compare against a single meal, a single commute, a single flight.

Where the 2-tonne target comes from

The 2 tonnes CO2e/year figure is not an arbitrary round number. It's the level widely referenced in climate policy discussion as consistent with limiting warming to 1.5°C above pre-industrial levels — the more ambitious goal in the Paris Agreement.

It is a shorthand, not a number taken from a single IPCC table. Published targets point the same way or lower: the 1.5-Degree Lifestyles report (Institute for Global Environmental Strategies, Aalto University and D-mat, 2019) proposes per-person lifestyle footprints of 2.5 tonnes CO2e by 2030, 1.4 tonnes by 2040 and 0.7 tonnes by 2050. So 2 tonnes a year is a useful reference point for the next decade, not a finish line.

Divide 2,000 kg by 365 days and you get roughly 5.48 kg CO2e per day. That's the daily budget this article works from.

The daily budget framework

A budget only means something once you can spend against it. Below is a breakdown of how quickly common food and travel choices eat into a 5.48 kg daily allowance, using the per-100g food factors and per-kilometre travel factors listed on this site's research page (Poore & Nemecek, 2018, for food; European Environment Agency data for transport).

Food — per 100g serving, share of a 5.48 kg daily budget:

Travel — per 10km trip, share of a 5.48 kg daily budget:

Two things jump out. First, a single 100g beef serving alone uses up more than half a day's budget — before any travel, heating, or electricity is counted. Second, a 10km diesel car trip uses more of the daily budget than an entire bus commute, and both dwarf a train trip of the same distance. Neither table includes home energy, water, waste, or digital use, which is why a 5.48 kg target is genuinely tight once you account for a full day, not just one plate or one trip.

A worked example

Consider one ordinary weekday: a 200g chicken breast at lunch (1,240 g CO2e, using the chicken factor above), a 10km bus commute each way (2,100 g CO2e for the round trip), and a 100g serving of cheese on dinner (1,350 g CO2e). That's already 4,690 g — 85.6% of a 5.48 kg daily budget — before breakfast, home heating, electricity, or anything else is counted. Swap the bus for a bike and the cheese for beans, and the same day drops to roughly 1,340 g, well under budget with room for other categories.

This is the core idea behind budgeting daily rather than staring at an annual number: small, specific swaps are visible immediately, not just at the end of a reporting year.

A quick decision checklist

Before assuming a "healthy" or "normal" day is automatically low-carbon, run through this:

• Did today include a serving of red meat or cheese? Each can use 20–55% of the daily budget on its own.
• Was any trip over a few kilometers taken by car or plane rather than train, bus, bike, or foot?
• Are home energy, water, and waste being counted at all, or only food and travel?
• Is the daily target being compared to a full day's total, or just a single category?
• Is the 5.48 kg figure being used as a guide rather than a pass/fail line? Daily totals swing a lot; the target describes the yearly average.

In Decarbonr

Decarbonr's dashboard is built around exactly this kind of daily framing. Its gauge shows today's CO2e against your daily goal, by category. The default goal is 2 tonnes a year (≈5.48 kg a day), a common shorthand for a lifestyle compatible with 1.5°C, and you can set your own in Settings. Once you have entries on 7 different days, the app adds a yearly estimate, shown next to the 2-tonne target and, for 32 countries, the country's average fossil CO2 per person. This tracking — the daily gauge, the goal, Insights, streaks and awards, and the country comparisons — is part of Base Access, one of the subscriptions (weekly, monthly or yearly) the app needs after its introduction screens. Faster meal logging by meal photo (sent through Decarbonr's server to OpenAI, only after you agree) or by barcode is in the AI add-on, which includes Base Access — useful if you want to log food without picking it by hand, but not required to see or track against the daily budget itself. Your entries are stored on your device, with no account.

The takeaway

A 5.48 kg daily carbon budget isn't a strict quota to hit every single day — it's a reference point that makes an abstract annual target concrete enough to act on. Once you can see that one beef meal or one short flight can use up half a day's allowance on its own, the highest-impact choices become obvious without needing to track every gram forever.

FAQs

What is a daily carbon budget? It's an annual climate target divided into a daily allowance — commonly 2 tonnes CO2e/year, or about 5.48 kg/day, used as a shorthand for a lifestyle compatible with the Paris Agreement's 1.5°C goal.

Is 5.48 kg CO2e per day realistic for most people right now? Not yet, for most people. The world average for fossil CO2 alone was about 4.7 tonnes per person in 2024, roughly 13 kg a day (Global Carbon Budget, via Our World in Data), before methane and other greenhouse gases are counted, and averages in many high-income countries are several times higher. The food and travel tables above show how quickly common choices use up the budget.

Does food or travel usually blow the daily budget first? Either can. A single high-carbon meal (beef, lamb, cheese) or a single long car or plane trip can each consume 20–55% of a 5.48 kg daily budget on its own, based on the emission factors above.

Can I set my own daily CO2e goal instead of the 2-tonne target? Yes — in Decarbonr, the daily goal is set in Settings. It is part of Base Access; the weekly Base Access plan has a no-cost trial where offered.

Does the daily budget include home energy, not just food and travel? A full daily footprint should include heating, electricity, water, waste, and other categories — this article's tables cover only food and travel to keep the framework simple; a complete day's total will typically be higher.

Ready to see your own daily number? See Decarbonr on the App Store: no account required.