App help

How challenges and daily missions reduce emissions

What each challenge avoids per kept day, how check-ins work, how to do a challenge with friends, and what the daily mission adds.

EarthReheal Team · 29 September 2026 · 2 min read · Checked on app v1.2.1

On this page
  1. What each challenge avoids
  2. Starting a challenge
  3. Checking in
  4. Doing it together
  5. The daily mission

A challenge is a commitment to one specific change for a set number of days, anywhere from 3 to 90. It works for two reasons. A behaviour kept up for a couple of weeks tends to stick. And every day you keep it, the app counts the emissions that day avoided.

What each challenge avoids

ChallengeWhat a kept day avoids
Cycle or walk to workThe emissions of your usual commute
Bus or metro weekMost of your usual commute's emissions
Carpool to workAbout half of your usual commute's emissions
Meat-free daysAbout 1.5 kg CO₂e
Cook, don't orderAbout 1.6 kg CO₂e
Refill, not PETThe bottled water you didn't buy
Lighter screensThe electricity from reduced device use

Travel challenges are measured against your own commute, so they count most for people who usually drive. Dry week and Smoke-free week are personal pledges. The scoreboard challenges (Battery quarter, Collector segregation streak and Cleanup contribution) tally what your collector or recycling partners have already recorded, so they don't add anything extra.

A challenge you create yourself tracks your progress but doesn't add to your offset, because there's no fixed factor for a goal you define.

Starting a challenge

Start with 7 or 14 days rather than 90. A shorter window you complete beats a long one you abandon.

Checking in

Each day, mark the challenge Kept, Skip or Slipped. Some challenges ask for simple proof: photos of lunch and dinner for meat-free days, for example. For travel challenges the proof is the trip itself, which the app logs from your office distance if you haven't logged it yourself. You get a small number of skips for days you genuinely can't do it. Two slips end the challenge.

Your active challenges also appear on the Day log tab, so you can check in while you log your day.

Doing it together

Up to 12 people can share a challenge. Invite friends by email if they already use the app, or share the invite code. If someone sends you a code, enter it under Invite code on the Challenges screen and tap Join. You'll see the details before you commit. A shared challenge is noticeably easier to keep.

The daily mission

Every morning the app suggests one small action, such as taking public transport once, carrying a reusable bag or skipping a single-use plastic item. Mark it done when you have. Where the action has a clear saving, it adds to your offset: a walk, a cycle ride or a public transport trip counts for about 2 kg CO₂e.

Completing the mission on consecutive days builds a streak. If you miss a single day, your monthly streak freeze covers it automatically.

Put this into practice with the EarthReheal app

Free on Android and iPhone. Know your footprint, sort any item, sell your scrap and join drives near you.

More help

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