One issue that may be exacerbating the increase in
atmospheric biogenic methane is the growth and spreading of methanogens around
the oceans due to several factors. The first factor is fertilization.
Fertilization and Ocean Currents
Where agricultural nutrients
like phosphorus and nitrogen are collecting along the coasts, there is more
potential food for methanogens. These farm and animal wastes create the
conditions for explosive growth of methanogens along the coast and in the deep
ocean as well. Some coastal regions show methane production up to ten times
above background levels due to the added nutrients. The coastal regions that
receive the most waste also have access to more ocean currents than other
coastal regions, leading to more distribution of methanogens via ocean
currents. It is thought that since the nutrient additions are seasonal, so too
is the growth and spread of coastal methanogens.
Warmer Oceans
Warmer oceans also extend the
biological range of methanogens by thousands of miles. According to the article
by Julie Majid in PetsnPals, suggests that this expanding habitat range is
leading to higher totals of methanogens in the ocean, which means more biogenic
methane is being released to the atmosphere.
“Areas that were once too cold to support their
metabolism are now perfect breeding grounds, expanding their total habitat by
an estimated 40 percent over the past decade. The organisms are moving into
Arctic ocean regions, tropical shallow seas, and mid-depth waters that never
harbored methanogen populations before.”
She calls it “a biological
invasion that feeds on climate change itself.”
Glacial Meltwater
Glacial meltwater contains
dormant methanogens, which are released into the sea as the ice melts. This
reintroduces ancient microbial strains into modern ocean environments. This
increases genetic diversity, which makes current populations more resilient and
productive when they interbreed with existing colonies. Some of these
once-frozen methanogens exhibit enhanced cold tolerance and more efficient
metabolic pathways. This, in turn, helps them to spread to more places in the
ocean.
Disturbance Via Deep-Sea Mining
Disturbing the ocean floor
during deep-sea mining can break open “sediment layers that contain
concentrated methanogen populations, releasing them into the water column where
they can spread more easily. These disturbances also expose the microbes to
different chemical environments that can trigger increased methane production.
Mining operations target the same deep-sea environments where the highest
methanogen concentrations exist, creating perfect conditions for widespread
microbial dispersal.”
She also notes that the
disturbance may mix different colonies together, which can also aid their
proliferation as more robust hybrid populations.
Potential Implications
The potential implications
for increasing atmospheric methane could be huge and, by some measures,
potentially catastrophic. However, we need a better understanding
of oceanic methanogenesis in order to better understand the
implications of the growth and spread of methanogens and how to mitigate them.
“Mathematical models incorporating the new methanogen
data predict that these organisms alone could increase global atmospheric
methane concentrations by 100 percent by 2045. The projections account for
their expanding habitat range, increasing reproduction rates due to warming
temperatures, and the compounding effects of their rapid global dispersal.
These estimates assume current trends continue without major interventions to
limit ocean warming or methanogen populations.”
“The timeline could accelerate further if these
organisms continue adapting to new environments or if ocean warming happens
faster than current projections suggest. Some research teams believe the
doubling could occur as early as 2040 if multiple feedback loops reinforce each
other simultaneously. This potential methane surge would fundamentally alter
Earth’s climate trajectory, making current greenhouse gas reduction targets
insufficient and requiring entirely new approaches to climate mitigation that account
for biological methane sources.”
Other research has recently
shown that warmer atmospheric temperatures lead to warmer wetland temperatures,
which can also increase atmospheric methane. The research showed increasing
methane releases from satellite-measured methane hotspots such as the tropical
wetlands of the Amazon and the Congo regions. Tropical wetlands are a leading
candidate for increasing atmospheric methane. Thus, warmer wetlands can also
lead to the growth and spread of methanogens in that environment.
References:
New
Data Says Earth’s Dangerous Warming Traced To A Hidden Methane Culprit. Julie
Majid. Petsnpals. September 1, 2025. New
Data Says Earth’s Dangerous Warming Traced To A Hidden Methane Culprit
Scientists
may have solved the mystery behind a top climate threat. Shannon Osaka. The
Washington Post. November 4, 2024. Scientists
may have solved the mystery behind a top climate threat
No comments:
Post a Comment