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. [CONFIRM: the precise derivation and any single canonical IPCC citation for "2 tonnes per person per year" should be verified against a specific IPCC report or assessment cycle before this figure is presented as an official IPCC number rather than a widely used shorthand target.]
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 per-100g food emission factors and per-kilometer travel emission factors drawn from published research (Poore & Nemecek, 2018, for food; European Environment Agency data for transport).
Food — per 100g serving, share of a 5.48 kg daily budget:
| Food (100g) | CO2e | % of daily budget |
|---|---|---|
| Beef | 2,990 g | 54.6% |
| Lamb | 2,420 g | 44.2% |
| Cheese | 1,350 g | 24.6% |
| Pork | 1,220 g | 22.3% |
| Chicken | 620 g | 11.3% |
| Fish | 550 g | 10.0% |
| Eggs | 450 g | 8.2% |
| Milk | 320 g | 5.8% |
| Tofu | 200 g | 3.6% |
| Beans | 100 g | 1.8% |
| Vegetables | 50 g | 0.9% |
Travel — per 10km trip, share of a 5.48 kg daily budget:
| Mode (10km trip) | CO2e | % of daily budget |
|---|---|---|
| Airplane | 2,550 g | 46.5% |
| Car (diesel) | 1,920 g | 35.0% |
| Bus | 1,050 g | 19.2% |
| Train | 410 g | 7.5% |
| Bicycle / walking | 0 g | 0% |
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 hard cutoff, or as a general orientation point? [CONFIRM: individual daily variance is expected; treating any single day as pass/fail may misrepresent how annual budgets actually work.]
In Decarbonr
Decarbonr's dashboard is built around exactly this kind of daily framing. The app's central circular gauge shows your current-day CO2e against a goal you set, with the 2-tonne/year (≈5.48 kg/day) Paris-aligned target offered as a reference point. This tracking — the daily gauge, goal-setting, streaks and achievements, and comparisons against country-level averages — is part of Decarbonr's core subscription, which starts with a free trial before converting to a paid weekly, monthly, or yearly plan. Faster meal logging via the AI photo scanner (GPT-4 Vision) or the barcode scanner is a separate, optional paid add-on on top of that subscription — useful if you want to populate your daily number without manual entry, but not required to see or track against the daily budget itself. All tracking happens on-device, with no account required to start.
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 Paris Agreement-aligned reference point.
Is 5.48 kg CO2e per day realistic for most people right now? [CONFIRM] This article does not have a verified, in-repo source for current national or global average daily per-person emissions, so no direct comparison figure is given here. What the food and travel tables above show is how quickly common choices consume that budget in isolation.
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 — goal-setting is part of Decarbonr's core tracking features, available with the app's subscription (after a free trial).
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? [Try Decarbonr on the App Store] — free trial, no account required.