Crude oil: Impact on nature
Flares, leaks, spills and tailings beyond the exhaust pipe
What this tab covers What taking energy from this source does to land, water, air and climate, wildlife and ecosystems, with life-cycle emissions and land use where measured.Burning oil is the main impact, but extraction adds flaring, methane leaks, spills and, for oil sands, large mines and tailings ponds.
Life-cycle emissions about 264 (combustion only) g CO2/kWh of fuel heat1 Converted from the IPCC default of 73.3 t CO2/TJ. Oil is a minor power source, so no harmonised life-cycle electricity figure is used here. Upstream flaring and methane add to this. Land use about 895 (oil sands mining disturbance, 2013) square km10Effects on nature
| Area | Effect | Size | How it is reduced |
|---|---|---|---|
| Climate (combustion) | Each unit of heat from oil emits less CO2 than coal but more than gas. Oil shale is the most carbon-intensive.1 | 73.3 t CO2/TJ crude oil; 107 t CO2/TJ oil shale and tar sands | Efficiency, electrification of transport, biofuels and synthetic fuels |
| Climate (flaring) | Gas produced with oil is often burned at the wellhead for lack of a pipeline.12 | 151 bcm flared in 2024, emitting 389 Mt CO2e (46 Mt CO2e of it as unburnt methane); about $63 billion of energy wasted | Gas capture and use, reinjection, bans on routine flaring |
| Climate (methane) | Venting and leaks from oil operations release methane.13 | About 45 Mt CH4 from oil in 2024 | Leak detection and repair, vapour recovery |
| Sea and coast (spills) | Tanker and pipeline spills poison wildlife and coasts. Tanker spills have fallen sharply since the 1970s.14 | About 10,000 t from tanker spills in 2024 | Double hulls, routing rules, response capability |
| Land (oil sands mining) | Boreal forest and peatland are stripped to reach bitumen ore within 75 m of the surface.10 | About 895 square km disturbed by 2013, out of 4,800 square km of mineable area | Reclamation; in situ (steam) extraction for deeper deposits |
| Water and waste (oil sands tailings) | Bitumen extraction leaves fluid tailings that must be contained for decades.15 | 1.392 billion cubic metres of fluid tailings and 417 million cubic metres of mine water at end-2022 | Tailings treatment and dewatering, pit lakes, water recycling |
Most of oil's climate impact happens in engines and boilers, far from the oilfield. Upstream impacts vary greatly. Global average methane intensity of oil and gas is about 1%, and the best and worst producers differ by a factor of about 100, so the same barrel can have very different footprints depending on where and how it is produced.
Local effects range from the large surface footprint of Alberta's mines to fracking's water and truck traffic, and to offshore spills. Tanker spills are now far smaller than in the 1970s, but single events can still dominate a decade's total.
Sources
- 2006 IPCC Guidelines for National Greenhouse Gas Inventories, Vol. 2 Energy, Ch. 1 Introduction (Tables 1.2 and 1.4) IPCC, 2006
- Oil sands facts and statistics Government of Alberta, 2024
- Global gas flaring hits highest level since 2007 (Global Gas Flaring Tracker 2025) World Bank, 2025
- Global Methane Tracker 2025: Understanding methane emissions IEA, 2025
- ITOPF oil tanker spill statistics for 2024 ITOPF, 2025
- Oil sands tailings and mine water fact sheet Government of Alberta, 2024