Science · Missions & impact ledger · iChallenge network
Earth-science rounds every day, plus missions that leave a measurable mark where you live.
What fraction of Earth's surface is covered by ocean?
Oceans cover roughly 71% of the planet's surface and hold about 97% of its water.
One ranked attempt per day. Practice as much as you like.
What players on EarthChallenge.com have actually done. Every check-in and approved proof adds one line. The math behind each number is shown on the card, with its source. Full ledger →
Local missions are things you can do where you live — in Columbus that means your own street, shoreline or school. Global missions add up across every arena on the network.
Photograph and identify ten wild species (plants, birds, insects, anything) within walking distance of home. Post the list and a link.
+1 actions when approvedCounted as one completed survey. Upload your sightings to iNaturalist or GBIF and your list becomes open biodiversity data.
Counted with SavingTheWorld.org
Plant a native tree where it can survive, or sponsor one through a verified planting program. Post the species, the place and a photo or receipt link.
+1 trees when approvedOne tree. We count trees planted or protected, not carbon, because a sapling's CO₂ uptake depends on survival, species and decades of time.
Counted with SavingTheWorld.org
Spend an hour clearing litter from a beach, riverbank, park or your own street. Post a photo link or a short note with the spot and roughly how much you collected.
+4 kg waste when approvedOne full standard trash bag of mixed litter weighs about 4 to 6 kg (Ocean Conservancy International Coastal Cleanup averages). We count 4 per approved cleanup.
Counted with SavingTheWorld.org
Seven days with no disposable cups, bottles, bags or cutlery. Carry your own. Check in each night.
+0.1 kg waste per check-inA typical day of single-use items (one coffee cup, one bottle, two bags, one set of cutlery) weighs about 0.1 kg (Ocean Conservancy item weights).
Counted with SavingTheWorld.org
Every night, switch off lights in empty rooms and kill standby power on TVs, consoles and chargers. Check in before bed.
+0.1 kg CO₂e per check-inStandby and lighting waste is ~0.3 kWh per household per evening; at the US grid average of ~0.37 kg CO₂ per kWh (EPA eGRID) that is ~0.1 kg.
Pick one climate or nature problem you can see from where you live. In three weeks, ship a page, a tool, a service or a pilot that moves it. Post the link and what you learned.
+1 actions when approvedCounted as one shipped founder sprint. Entrepreneurs.org reviews these for its builder spotlight.
Counted with Entrepreneurs.org
SavingTheWorld.org is the impact home of the eCorp network: 2% of every venture is set aside for the planet and for keeping AI safe. Planet-track missions roll up there.
Founder trackEntrepreneurs.orgEntrepreneurs.org backs people who turn a challenge into a venture. Founder-track missions are build sprints: ship a thing, show the proof, get seen.
Community trackContrib.comContrib.com is where contributors earn a stake in the ventures they help. Community-track missions count hours and local actions.
Free alerts for every Florida county when sewage is spilled, algae toxins are detected, lake discharges surge or the Weather Service issues a warning. The local-mission radar for this arena.
Alerts, every marketAlertStream.comEcoBoard’s alert engine expanding beyond Florida: weather warnings, water quality and other concerning events for any place you follow, so a mission can start the day something changes near you.
Daily briefingClimateNews.comThe climate newsroom of the network: what moved today, with sources, so the daily round has something real to ask about.
Check-ins are self-reported and shown as logged. Proof missions are reviewed by a person before they count as verified. Each per-action figure is a conservative public estimate (EPA, IEA, UN Environment or peer-reviewed sources named on the card), rounded down. These numbers are for keeping score and staying honest, not for carbon accounting or offsets. If you think a figure is wrong, say so on the contact form and we will fix it in public.
Live counts from EarthChallenge.com. All arena stats →
Earned on any arena, shown on your profile everywhere.
Add your email to keep your level, streak and badges if you switch devices, and carry them to every iChallenge arena. One email when you save; no spam.
Fund a prize on EarthChallenge.com and your brand sits on the challenge card, the leaderboard and every finisher's share. Prizes only appear once they're funded, so players can trust what they see.
Post a link or note as proof. Approved entries finish the challenge and earn the Finisher badge.
Sponsors can fund cleanup and conservation prizes. Each funded prize is listed on its challenge card.
Everyone on this arena gets the same five questions each day, from easy to hard. You get one ranked attempt; practice rounds are unlimited.
100 points per correct answer, up to 50 more for answering quickly, a combo multiplier for answers in a row, and 150 bonus points for a perfect round.
Yes. Playing, streaks, badges and leaderboards are free. Some challenges carry a sponsor-funded prize; the challenge card shows it when one is funded.