Concentrations of methane are increasing over the UAE, a new study has revealed.
Levels are high in coastal areas, where there are landfill sites and sabkha habitats – mud flat or salt flat areas – both of which are key sources of the gas.
Inland, concentrations are high around the Hajar Mountains, where methane is thought to be emitted by farms and microorganisms that live in wadis.
The researchers at Khalifa University in Abu Dhabi behind the new study in Frontiers in Environmental Science used satellite data to calculate concentrations of the gas – which has the chemical formula CH4 – over the past few years.
They found that “column values” of methane, known as XCH4, were increasing by around nine parts per billion per year.
This was double the increase recorded over two other locations – the Arctic and Argentina – for which similar work has been carried out using satellite data.
Increasing population
Dr Diana Francis, an assistant professor in the earth sciences department at Khalifa University and the first author of the study, said that the increases in concentration were probably mostly the result of human activity “related to population growth and economic development in the region and globally”.
“Landfill sites and industrial sites in general are the most significant contributors to anthropogenic emissions and, therefore, they are the key sources to focus on when it comes to strategies towards net-zero targets,” she said.
A large proportion of the methane over the UAE may come, she said, from countries to the north, given that the prevailing winds are north-westerlies.
Methane is described as being 86 times more potent than CO2 at warming the Earth’s atmosphere over a two-decade period.
While CO2 retains its warming capacity for about 200 years, methane only remains for around nine to 12 years. As a result, measures to cut methane emissions can have a major effect on limiting temperature rises in a relatively short period.
Contributing to global warming
Scientists estimate that methane is responsible for around 0.5°C of the increase in temperatures experienced since pre-industrial times. This is just over one-third of total warming.
The UAE is among 150 nations to have signed the Global Methane Pledge – a commitment to ensure that methane emissions in 2030 are 30 per cent lower than in 2020.
Pledge organisers say that cutting methane emissions by 30 per cent by 2030 “could eliminate over 0.2˚C warming by 2050” .
Dr Francis said that cutting methane emissions required the implementation of regulations, the introduction of new technology and, across various sectors, efforts to minimise leaks, losses and emissions.
Methane-absorbing vegetation
Even in natural habitats that give off significant amounts of methane, such as the sabkha habitats, efforts can be made to reduce emissions.
These include helping to promote the growth of native vegetation, including plants adapted to high salinity, such as Salicornia.
“Vegetation acts as a sink for methane and can help reduce emissions by absorbing the gas,” said Dr Francis, who heads Khalifa University’s environmental and geophysical sciences laboratory.
Another way to reduce methane emissions is to avoid soil disturbance, as this can release stored carbon and trigger the production and release of methane, she added.
“By reducing methane emissions, we can help mitigate significantly the rate of global warming in the coming decades and its associated impacts, such as rising temperatures, extreme weather events and sea-level rise,” said Dr Francis.
The researchers behind the latest study are keen to see more measurements of CH4 levels taking place in the UAE.
This would help, for example, to distinguish between methane that originates locally and regionally, and between that caused by human activity and nature.
“This is very critical if we want to put in place effective measures and strategies for emission reduction,” Dr Francis added.
Other authors of the new study are based at Dubai Electricity and Water Authority and the Stevens Institute of Technology in the US.
