Making methane visible

Methane (CH 4) is one of the most important greenhouse gases, and an important energy carrier in biogas and natural gas. Its large-scale emission patterns have been unpredictable and the source and sink distributions are poorly constrained. Remote assessment of CH 4 with high sensitivity at a m 2 spatial resolution would allow detailed mapping of the near-ground distribution and anthropogenic sources in landscapes but has hitherto not been possible. Here we show that CH 4 gradients can be imaged on the <m 2 scale at ambient levels (â ˆ1/41.8 ppm) and filmed using optimized infrared (IR) hyperspectral imaging. Our approach allows both spectroscopic confirmation and quantification for all pixels in an imaged scene simultaneously. It also has the ability to map fluxes for dynamic scenes. This approach to mapping boundary layer CH 4 offers a unique potential way to improve knowledge about greenhouse gases in landscapes and a step towards resolving source-sink attribution and scaling issues. © 2016 Macmillan Publishers Limited. All rights reserved.