Zero Trace CO₂e Report — Twelve Apostles Trek | 4-Day Great Ocean Walk (Victoria)
Results Summary
- Estimated total per person: ≈ 540 kg CO₂e
- Offset per person (200%): ≈ 1.08 t CO₂e
- Group total for context (10 guests): ≈ 5.40 t CO₂e
Method: high-estimate with Well-to-Tank (WTT) and aviation non-CO₂ effects via RF = 1.9; includes single-origin guest flights, all meals (included + off-tour), on-tour road shuttles & stays, and +10% uncertainty uplift.
Purpose
Conservatively estimate greenhouse gas emissions (CO₂e) across Scopes 1–3, report per person (with group totals for context), and state the 200% offset applied per person.
Key Tour Info
- Region: Victoria, Australia
- Duration: 4 days / 3 nights
- Start/Finish: Melbourne (return logistics to/from the Great Ocean Walk)
- Group size used for context totals: Maximum 10 people
- Trail distance: 46 km total; difficulty: Moderate
- Style: All-inclusive lodge-based trek (pack-free day walking)
Scope & Boundaries
- Scope 1: On-tour vehicle fuel (Melbourne ⇄ trailheads and local shuttles).
- Scope 2: Purchased electricity where directly attributable (otherwise captured via accommodation factors).
- Scope 3: Guest flights to/from the start (single-origin rule), accommodation nights, all meals (included + off-tour), and uncertainty uplift. Capital goods excluded.
- Method frame: GHG Protocol; DEFRA-aligned factors with WTT; aviation RF = 1.9.
Feeder Hub (Guest Flights) — Single Origin Rule
- Chosen origin hub: Sydney (SYD) (nearest other major city for a Melbourne-based tour).
- Routing applied: SYD ↔ MEL (return) per person.
Emission Factors & Conservative Defaults
- Flights: Distance-based economy factors (DEFRA), WTT included, RF = 1.9 applied.
- Road (mini-coach): Higher “local bus” passenger-km factor to reflect lower occupancy (conservative).
- Accommodation: Room-night method (Oceania benchmarks) for 3 lodge nights.
- Meals: Meat-heavy mixed diet at ~2.5 kg CO₂e/meal (upper-bound).
- Uncertainty uplift: +10% added to the subtotal where primary meter/fuel data is missing.
Activity Data Applied (this estimate)
- Guest flights: SYD ↔ MEL return (≈ 706 km each way; ~1,412 km total).
- On-tour road: ≈ 600 km total (Melbourne → Apollo Bay region; Twelve Apostles/Port Campbell → Melbourne; plus local shuttles) — set deliberately high for conservatism.
- Accommodation: 3 nights (lodge).
- All meals consumed: 12 meals/person (4 days × 3/day), regardless of inclusions.
Results — Per Person (high-estimate, no tables)
Flights (SYD ↔ MEL, return; WTT + RF = 1.9): ≈ 310 kg
On-tour road (≈ 600 km; conservative passenger-km factor): ≈ 90 kg
Accommodation (3 lodge nights; region benchmark): ≈ 60 kg
All meals (12 × ~2.5 kg): ≈ 30 kg
Subtotal: ≈ 490 kg
+10% uncertainty uplift: ≈ 49 kg
Estimated total per person: ≈ 540 kg CO₂e
Reporting focus is per person. Group totals are provided only for context.
Group Totals (context, 10 guests)
- Tour total: ≈ 5.40 t CO₂e
- (Offsets are applied per person only: ≈ 1.08 t CO₂e retired per traveller.)
Assumptions (transparent)
- Origin hub fixed: Sydney for all travellers (single-origin rule).
- Aviation: Distance-based; WTT included; RF = 1.9 to reflect non-CO₂ warming.
- Road distance: Not listed in full on page; used known Melbourne ⇄ Great Ocean Walk transfer distances and added buffer to remain conservative.
- Accommodation: Lodge nights counted via room-night benchmarks to avoid underestimation.
- Meals: Every meal during the trip window counted, independent of inclusions.
- Uncertainty: +10% uplift applied to subtotal to capture unknowns.
Versioning
Generated 23 Aug 2025 (Australia/Perth). Factors reviewed at least annually or when official sources update.
References