Context: Termites are detritivore insects that primarily consume decaying plant material such as wood, leaf litter, and soil humus. They are consider as natural sources of methane emissions, alongside wetlands, wild animals, livestock, and geological features like volcanoes. Termites are estimated to account for 1-3% of methane emissions on a global scale.

Each termite produces, on average, about half a microgram of methane per day, a seemingly insignificant amount. However, when this is multiplied up by the world population of termites, global methane emission from this source is estimated to be about 20 million tonnes each year.

Greenhouse Effect and Greenhouse Gases:

The greenhouse effect occurs when certain gases in a planet’s atmosphere trap heat radiated from the planet’s surface, leading to a rise in its average surface temperature.

Greenhouse gases like carbon dioxide, methane, nitrous oxide, and others absorb and reduce the escape of infrared radiation from the planet’s surface into space.

Major Treaties to Limit GHGs:

Kyoto Protocol (1997):

The Kyoto Protocol is an international treaty adopted in 1997. It has aim to reduce the emission of gases that contribute to global warming. The protocol called for reducing the emissions of six greenhouse gases in 41 countries plus the European Union to 5.2 percent below 1990 levels. The Kyoto Protocol is an international agreement having link with the United Nations Framework Convention on Climate Change. It is by committing industrialized countries and economies in transition to limit and reduce greenhouse gases (GHG) emissions in accordance with agreed individual targets.

Principles of the Kyoto Protocol

1. Carbon dioxide (CO₂);
2. Methane (CH₄);
3. Nitrous oxide (N₂O);
4. Hydrofluorocarbons (HFCs);
5. Perfluorocarbons (PFCs); and.
6. Sulphur hexafluoride (SF₆)

Paris Agreement (2015):

• A legally binding international treaty on climate change aiming to limit global temperature increase.
• Paris Agreement requires all countries to set emissions-reduction pledges.

Termite Connection to GHGs:

• Termites have been recognize as contributors to global methane emissions since 1932.
• Earlier estimates in 1982 suggested they were responsible for 150 Tg (teragrams) of methane emissions annually, accounting for 40% of total methane emissions at the time (though this was an overestimation).
• Recent data from the Global Carbon Project indicates that termites contributed 9 Tg of methane emissions out of the 576 Tg emitted globally in 2008-17.
• Termites consume decaying organic matter, leading to methane emissions as methanogenic microorganisms in their gut break down cellulose and release methane.
• Termites partially mitigate their emissions by depositing specific microbes in their mounds, which capture some of the methane.

Problems in Data Collection:

• Data on termite emissions is collected through two main methodologies, but they have limitations.
• The first method studies individual termites in a laboratory setting but does not account for methane capture by mounds.
• The second method measures emissions from individual mounds in forests but misses emissions from individual termites outside the mound.
• Challenges in estimating termite emissions include the lack of data on most termite species, difficulties in determining termite biomass, and limited information on mound methane capture.
• Variability among termite colonies across different geographical locations is also a factor to consider.
• The impact of climate change on termite behavior and emissions is not fully acknowledge.

Conclusion:

• Declining biodiversity and predator populations could lead to an increase in termite populations and, consequently, methane emissions.
• One potential solution to mitigate termite emissions is to restore ecological balance.

Understanding and accurately quantifying termite-related methane emissions is essential. So that developing strategies to address this environmental concern and mitigate its impact on the greenhouse effect is possible.
Down to Earth Summary (01-15th May 2023)