01
Your tasks are ready
Every day the app picks three tasks that fit your profile: one easy, one medium, one hard. From transport to food, from energy to waste.
The gamified carbon app
Turn your footprint into a leaf.
Three small tasks a day. Each one a measurable CO2 saving. Streaks, celebrations and a tree that grows with your savings: Source Green turns cutting carbon into a game you play every day.
Atmospheric CO2 at Mauna Loa, 14 October: 426.84 ppm
- 500tasks
- 5categories
- 10levels
- 6languages
- 308tasks tied to a published source
The game loop
One day, three tasks, one celebration.
At the heart of Source Green is a simple loop. It starts fresh every day, and every round ends with a real carbon saving.
02
Complete and log
Done it? Tick it off with a single tap. The carbon you avoided goes straight to your account and your daily total updates.
03
Celebrate
Every second task brings the milestone of the day: confetti, the tree-day equivalent of the carbon you avoided and a short "Keep it up!"
04
Keep your streak
Your unbroken days are counted and your activity calendar fills up. Your history keeps every task with its date and saving.
Level tree
As your savings grow, so does your tree.
Your total savings take you through ten levels. Level two takes 5 kg; level ten takes 225 kg in total. Drag the slider and grow your own tree.
5 kg to the next level
0tree-days
0km of driving
0cups of coffee
0kWh of electricity
Equivalents use the app's own factors: 1 kg CO2e is about 6.2 km in a petrol car, 26 cups of coffee and 6 tree-days (a tree absorbs 60 kg of CO2 a year).
Features
A reason to come back every day.
Your weekly carbon budget
Compare your weekly footprint with the Paris Agreement target. While the gauge stays green, you are below the target.
Paris target: 47 kg / week
Your savings, category by category
Where did you make the biggest difference this month? The ring chart and ranked bars tell you.
- Food11.74 kg
- Consumption and Shopping7.50 kg
- Energy4.20 kg
- Transport3.28 kg
- Waste and Water3.20 kg
A comment just for you
AI compares today's saving with yesterday's and writes you a short comment.
You saved 2.20 kg today, 29% more than yesterday. Great work!
Based on an in-app comment
Numbers you can picture
What 29.92 kg of savings means in the real world. The app converts every total into these units.
182tree-days
187km of driving
787cups of coffee
63kWh of electricity
Your city's green map
See collective savings district by district, with a district ranking. Districts with fewer than three users are never shown.
The planet's pulse
Atmospheric CO2 measured at Mauna Loa, from NOAA data every day. The last 30 days:
426.84 ppm14 October
Start in seconds
Sign in with Apple, Google or email. Lock the app with Face ID if you like; it opens in your phone's language.
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Tasks
500 tasks. 5 categories. All from real life.
100 tasks in every category, from easy to hard. The app shows the carbon each task avoids and the source behind the number.
Transport 100 tasksFood 100 tasksEnergy 100 tasksConsumption and Shopping 100 tasksWaste and Water 100 tasks
Take the train instead of flying today 26.15 kgHardCancel the flight and travel overland 19.21 kgHardTake the coach on your business trip today 12.06 kgHardTake the train instead of driving today 10.33 kgMediumVisit somewhere near instead of far 6.00 kgHardGo vegan for the day 2.74 kgMediumSpend a fully vegan day 2.74 kgHardSpend the day vegan and local 2.74 kgHardFill the day with vegan plates 2.74 kgHardSpend a vegan day with the family 2.74 kgHardKeep the heating at eighteen all day 3.32 kgHardTrap the heat with doors and curtains today 3.32 kgHardSpend the day on the least electricity possible 2.85 kgHardTurn the heat down two degrees today 2.60 kgMediumDo not switch the dryer on today 2.50 kgHardBuy only second hand today 5.00 kgMediumPut off replacing the tablet 2.50 kgMediumBuy no fast fashion today 1.92 kgMediumDo no shopping at all today 1.92 kgHardResist the pressure of the new model 1.50 kgEasyShower in three minutes today 1.28 kgHardShower in four minutes today 0.96 kgMediumHand in waste batteries and electronics 0.50 kgMediumCompost all your organic waste today 0.40 kgHardDo not rinse dishes under the running tap 0.30 kgEasy
Make the holiday trip by train today 19.38 kgHardIntercity by high speed train 15.50 kgMediumTake the coach for a long trip today 11.30 kgHardTake the train to the next city 7.34 kgMediumTake the train to the nearby district 5.17 kgMediumEat vegan today 2.74 kgMediumEat no animal protein today 2.74 kgHardSpend the day completely vegan 2.74 kgHardSpend the day fully vegan and waste free 2.74 kgHardSkip both dairy and meat today 2.35 kgHardHalve your gas use today 3.32 kgHardKeep the thermostat at seventeen all day 3.00 kgMediumManage all consumption by hand today 2.85 kgHardSpend the day cool without air conditioning 2.50 kgHardFind the energy leaks at home today 2.50 kgHardZero furniture purchases today 3.00 kgHardCarry on using your device 2.50 kgMediumGive an experience as a gift 1.92 kgMediumZero fast fashion today 1.92 kgHardWait before you buy today 1.00 kgMediumDiscover the benefits of a cold shower 1.00 kgMediumProduce no rubbish today 0.60 kgMediumSet all appliances to the lowest water mode 0.50 kgHardWash a full load of laundry 0.30 kgEasyUse vinegar instead of bleach 0.30 kgMedium
Science
Open sources, transparent maths.
Task savings are based on published emission factors. Each factor's publisher, year and link are listed on the Data Sources screen in the app.
EmberGrid carbon intensity
DESNZ 2026Public transport and travel
IPCC 2006Fuel combustion
Poore & NemecekFood emissions
Scarborough et al.Diet patterns
US EPAWaste and recycling
WWF Sweden & SLUCoffee and drinks
Türkiye ETKBNational grid factor
308 / 500
tasks tied to a published source
Carbon figures in the app are estimates, not binding measurements.
Privacy
Privacy first.
Nobody stands out alone
The heat map only shows districts with at least three users. Your location is kept at province and district level only.
No ads, no tracking
The app has no ads and no third-party analytics. Your data is never sold for marketing.
Your data stays in the EU
Account and usage data is stored on AWS servers in Frankfurt, with encrypted backups.
Delete whenever you want
You can delete your account in the app. Your tasks, codes and notifications go with it.
The film
See Source Green in 30 seconds.
Daily tasks and celebrations, savings, live CO2 readings, the city map and the data sources. Screens recorded in the app itself.
The app speaks six languages:
TürkçeEnglishDeutschFrançaisEspañolItaliano
Contact
An idea, a question or a partnership?
Write to the Source Green team; we are here for support, partnerships, press and data protection requests.