In August 2012, two Australian research scientists attached a highly sensitive spectrometer to a vehicle with a GPS tracker and took a 700 kilometre drive around gas fields in Queensland.
Starting at 3.30am in the morning, Dr Isaac Santos and Dr Damien Maher, of Southern Cross University, wanted to measure the levels of methane and carbon dioxide in the air around coal seam gas fields operated by BG Group, formerly known as British Gas.
Twelve hours of driving took them past fields with about 300 wells that tap coal seams to release gas, often with the help of hydraulic fracturing (fracking) technology.
They also drove past other areas where you might expect levels of methane to be high such as wetlands, fields of cows and sewage treatment plants.
The researchers found methane levels at the gas fields were triple the background levels.
The chemical fingerprints of the methane they detected near the gasfields — known as isotopic signatures — matched those from the gas produced from the wells.