NASA (National Aeronautics and Space Administration), through its EMIT project, detects and publishes data on methane emission sources, accessible through the portal https://earth.jpl.nasa.gov/emit/data/data- portal/Greenhouse-Gases/

Methane is a powerful greenhouse gas and therefore contributes to global warming and climate change. The effect of methane is quantified in different time horizons, 84 times more powerful than carbon dioxide over a period of 20 years; 25 times more powerful in a period of 100 years.

Data from the EMIT project shows two important methane emission sources (plumes) in the Iberian peninsula, one near Pinto (Madrid) and the other near Alcantarilla (Murcia).

---

Pinto plume

Pinto emission focus has a perimeter of 15.2km and a surface of 14.8km², with a maximum concentration of 6084ppm (the average concentration of methane in the atmosphere is 2ppm, 3000 times less).

This emission focus matches the Pinto biomethanization plant:

According to its website, “It allows 140000 tons of domestic waste from the organic container to be treated annually, out of the total tons generated by the more than 1880000 inhabitants who live in the municipalities that make up the Commonwealth of the South.”

---

Alcantarilla plume

The emission focus of Alcantarilla has a perimeter of 8.6km and a surface of 5.5km2, with a maximum concentration of 1900ppm, this is 1000 times more than the concentration of methane in the atmosphere.

This emission focus matches the Cañada Hermosa waste treatment center:

Its website explains that “The waste management center is located in the Murcia district of Cañada Hermosa, in the north-west of the municipality of Murcia, about 14 km from the capital. It carries out the appropriate management of urban waste, treatment, recovery, disposal and valorization, with extensive facilities equipped with the most modern technology”, being a “point of reference in innovation and a symbol of the circular economy”

---

Amount of emitted methane

The data from the EMIT project is not sufficient in order to evaluate the total content of methane released into the atmosphere, but we can make some approximate calculations.

Assuming an emission upward velocity of 0.5km/h, and constant characteristics of the emission, the total volume of methane expelled is equivalent to the surface area of the emission multiplied by the upward velocity and by the time period to be considered, taking into account the average concentration of the emission.

Thus, the Pinto plume emits, during 10 hours, the equivalent to: 14.8km² x 0.5km/h x 10h x (3000ppm/1000000) = 0.222km³ of methane. Methane density is 0.717kg/m³ at room temperature, so total emitted methane weight would be approximately 159000 tons every 10 hours.

The Alcantarilla focus emits 5.5km₂ x 0.5km/h x 10h x (1000ppm/1000000) = 0.027km³ of methane every 10 hours. Considering again a methane density of 0.717kg/m³, the total emitted weight would be approximately 19,700 tons of methane every 10 hours.

Both values, especially Pinto’s, are very high. These sources of emission are clear contributors to climate change and their management should be evaluated.