Here's an example of some of the early research on methane detection from space (using SCIAMACHY, which has enough sensitivity to detect but not to localize wel

Here's an example of some of the early research on methane detection from space (using SCIAMACHY, which has enough sensitivity to detect but not to localize well): https://www.pnas.org/content/113/35/9734 https://www.pnas.org/content/113/35/9734 As documented in the paper, these space-based observations were later followed up by very high-spatial-resolution (1-3 m) airborne spectroscopic observations that revealed hundreds of sources in the Four Corners region of the US. The linked paper has a nice video of such a leak. The rates follow a very heavy-tailed distribution, meaning that a few big leaks dominate the total, at least for now. There are also complex time-dependent signatures associated with leaks depending on the source - gas pipelines vs. suboptimally-operated landfills. There's room in the observing system for ground, air, and space-based measurements.