How to read this site
Every figure here is a screening indication: a reason to look closer, not a conclusion. These are the words the pages use.
- Pass
- One time a satellite or aircraft looked at a landfill. Most passes show no plume. Only usable passes, with enough coverage and few clouds, count.
- Plume
- A visible cloud of extra methane in an image, with a point of origin and sometimes a rate.
- Plume day
- A day on which at least one usable pass saw a plume at a site. Read it against how many usable passes the site had.
- 90% range
- The band we are 90% sure the true value sits in. It is shown with every estimate and every change.
- Inconclusive
- The change after a dated record was neither clearly down nor clearly up at the 97.5% level. It is a result, not a failure.
- Smallest detectable drop
- The smallest drop this site's own passes would have caught 80% of the time. If it reads 75%, a smaller real drop could have been missed.
- Insufficient data
- Fewer than eight usable passes, a range wider than two orders of magnitude, or a fit that failed its diagnostics. Shown in grey, never ranked.
- Data through
- The last observation date in the latest update. Sources publish about 30 days after an observation.
- Provisional
- A placeholder outline or an unconfirmed detection curve stands behind the figure, which may change.
- Restricted
- Rows from a source whose publication terms are not yet confirmed. They are held back from the public site.
Colours
Colour never stands alone; every result has an icon and a label. Red: strong evidence of a severe increase. Orange: strong evidence of a moderate increase. Yellow: an increase that is small or uncertain. Green: no increase indicated. Grey: not enough data.