Incredible amounts of greenhouse gases rise from the bottom of the Red Sea. According to researchers, their concentration in the region was 40 times higher than expected.
|Red sea gases Research, 2020.|
The gases are not only a problem for the climate, but also for the air quality. This is because they react with exhaust gases from shipping to form toxic nitrogen oxides.
The hydrocarbon gases ethane and propane escape in huge quantities from the seabed of the Red Sea and damage the environment to an extent equivalent to the emissions in the form of gas leaks from a group of large fossil fuel producers.
This was reported by researchers in an article published in the scientific journal Nature on Tuesday.
On their way into the atmosphere, the escaping gases mix with emissions from industrial shipping and are transformed into harmful environmental toxins, which are also very dangerous to human health.
The researchers had become aware of the natural source due to pollutant measurements in the region. The Middle East is generally a very oil and gas rich region, where more than half of the fossil fuels are stored.
As a result, many of these gases also enter the atmosphere there. But during an expedition in 2017, researchers from the Max Planck Institute of Chemistry had noticed that the concentration of ethane and propane over the northern Red Sea was up to 40 times higher than predicted.
The predictions took into account human influences in the region, so the question remained where the large amounts of gas came from.
Quantity of emissions comparable to Kuwait's gas lossesA detailed analysis of traffic volume, agriculture, biomass combustion and combustion of fossil fuels for electricity and heating was then carried out.
|Ethane and propane data.|
The result of a two-year search for the source was that the two gases had to come from somewhere else, namely the bottom of the Red Sea, from oil and gas reservoirs.
According to the researchers, the gases continue to react during the ascent and form nitrogen oxides with exhaust gases from shipping, which are dangerous to human health.
The researchers also put the amount of released gases into a visual relationship: according to their calculations, the amount of released gases should be equal to the gas losses of countries such as the United Arab Emirates or Kuwait.
As shipping in the region continues to increase, the reaction between the gases from natural sources and shipping emissions could have fatal consequences for air quality in the region, according to the researchers.
Leaks in underground reservoirsBased on this previous geological-tectonic knowledge, the researchers suspect that the ethane and propane released by the Red Sea comes from previously unrecognised sources on the sea floor.
"Since this region is known for its large oil and gas reserves, the hydrocarbons could rise from leaks in the reservoirs," explain Bourtsoukidis and his team.
But the saline depressions at the bottom of the Red Sea could also release the gases, as some of them are known for their high levels of organic material and hydrocarbons.
Even if we do not know the relative importance of the various submarine hydrocarbon sources, we assume that together they represent the unknown source identified in our measurements, the researchers say.
The gases released on the seabed then reach the water surface relatively quickly via surging water currents along the Egyptian coast and thus enter the atmosphere.
The new findings are also important for the environment and health. This is because ethane and propane react in the atmosphere with nitrogen oxides and form both ground-level ozone and peroxyacetyl nitrate - a trace gas that is toxic to humans and plants.
In the Red Sea, heavy shipping traffic in particular emits large quantities of nitrogen oxides, which can then react with the locally increased hydrocarbon gases.
The result is a significant deterioration in regional air quality, say Bourtsoukidis and his colleagues.
This problem could be exacerbated in the future when shipping traffic through the Red Sea and the Suez Canal increases.