The 323 sites that are identified with "human" activities -- other than the exploitation of oil, gas and coal -- are associated, for the most part, with waste disposal sites. Like all the places depicted in the map, they are "ultra-emitter" sites, defined as producing more than 25 tons of methane per hour -- the largest produced 574 tons per hour -- and the map therefore underestimates the importance of diffuse sites, including agriculture and wetlands.
The map also, like the satellite-based measurements on which it is based, underestimates methane emissions from the places -- notably places close to the Equator -- that are under cloud cover for much of the year.
The largest number of sites is in South Asia -- 156 in Pakistan, 76 in Bangladesh, and 56 in India -- and most are in or close to very large cities, Lahore, New Delhi and Dacca. There are no sites observed below latitude 16, or in the tropical, monsoon-affected metropolitan areas of Bengaluru, Chennai, or Jakarta.
The only "human" ultra emitter sites observed in South America -- 19 -- are in Argentina; there are none in Brazil. There are 4 sites in China, 3 in Russia, and 3 in Iran. Then there are countries with 1 ultra emitter site each: Australia, Czechia, Germany (a mystery, in apparently idyllic country east of Pegnitz), Mauretania (the only "human" methane site in all of Africa), Serbia, Ukraine, the US (near Fresno), and Uzbekistan.
The "human" observations are much more difficult to interpret than the oil and gas related observations. Most of the sites are in countries with low greenhouse gas emissions per capita, although India has large and growing overall emissions of methane and other greenhouse gases, including from the old and expanding coal industry. Many of the largest waste disposal and landfill sites are in countries -- or regions of countries -- that are difficult to observe with satellite-based instruments.
But the size of the methane emissions from these sites is very large indeed. The largest single site in the entire dataset -- the one that produced 574 tons of methane per hour on March 23, 2019 -- is at {90.42, 23.84} and corresponds to the Amin Bazar Landfill in North Dhaka, Bangladesh. Of the ten largest emitting sites in the data, seven are identified as of human origin, two are related to oil and gas (in Iraq and Turkmenistan) and one to coal (in eastern India.)
The history of the "human" sites is a vivid illustration, above all, of the extent to which methane emissions -- so colorless and odorless, so ethereal in discussions of the "low-hanging fruit" of global methane policy -- are co-located with other, far more proximate forms of pollution, including the pollution of land, water and neighborhoods. This history -- or these many histories -- is an illustration, too, of the local as well as global benefits of reducing methane emissions, and the human activities that produce them.