by Nabiha Shahab
Global sea levels are rising as a direct cause of rising earth temperatures. A recent US National Oceanic and Atmospheric Administration (NOAA) report reveals that sea level along the U.S. coastline is projected to rise, on average between 0.25 and 0.30 metres in the next 30 years (2020 – 2050). Higher global temperature melts glaciers and ice sheets in the high latitudes and also as the water warms, the volume of water in the ocean expands further.
The Meteorology, Climatology and Geophysics Agency (BMKG) Head of Climate Change Information Centre, Dodo Gunawan said that although sea level rise is found in small measurements in the Indonesian waters, “when combined with a few other weather variations, and marine weather phenomena including high tides or seasonal sea level rises, it still pose as disaster threats.”
“Such variations are indirectly the impact of climate change. Examples of extreme events, such as strong winds, hurricanes, are getting more intense, the frequency is getting higher and the intensity is getting stronger,” said Gunawan.
Indonesia, the largest archipelagic country in the world, is particularly susceptible to the threat of climate change. The country’s large and small islands and coastal dwellings will almost certainly be impacted by rising sea levels.
“Areas on the north coast of Java for instance, such as Semarang, Kudus have experienced abrasion and often suffer from floods caused by high tides. In these areas, sea levels have increased permanently. On top of that, there are daily and seasonal variations that cause floods during high tides,” he explained.
Gunawan said that directly or indirectly, climate change has impacted weather patterns in Indonesia: “Tropical cyclones for instance, naturally are limited to 10 degrees north and south latitudes, but now have often impacted Indonesia.” Indonesia, located at 6 degrees north latitude to 11 degrees south latitude, has until recently been spared from the brunt of tropical cyclones. He said that extreme conditions caused by global warming are increasingly felt both in the land and seas.
Rising sea levels exacerbates forest fires probability
Managing and controlling forest fires, especially in fire-prone peatland areas in Sumatra and Kalimantan becomes more important as a recent study found that rising sea levels increase severity of forest and land fires in coastal areas.
“We were surprised to find that rising sea levels could potentially exacerbate fires in coastal areas in Indonesia,” the University of Göttingen study’s lead author Anggi Hapsari told tanahair.net this week. “Our findings underline how the interaction between rising sea levels and dry climate may contribute to massive forest fires even in relatively fire-proof ecosystems, such as pristine peatlands. This reveals the potential hidden impact of sea level rise exacerbating climate warming.”
The research led by the University of Göttingen found clues in the ancient peatlands of Kalimantan presenting a good indicator of rising sea level and increase of salinity in the otherwise freshwater peatland ecosystem and its susceptibility to fires.
Peatlands are landscapes where dead organic matter is waterlogged with acidic water for and, much like pickles, prevents them from rotting. The process in essence conserves layers of organic matter that build up over time and, like rings in a tree trunk, it tells the story about the environmental condition at the time.
The study found that much higher concentrations of charcoal were found between 9,000 to 4,000 years ago or the mid-Holocene era, when sea level was higher than it is now, is a sign that at that time there were much larger forest fires .
However in a later period, or around 3,000 years ago, the fires were fewer than in the earlier mid-Holocene, despite irregular weather phenomenon that would have caused prolonged drought, making the forests drier and more susceptible to fires, which presented a puzzle.
A clue was that during the earlier period in the mid-Holocene period, researchers found a high proportion of mangrove pollen. “The pollen grains indicate the presence of mangrove forests which grow along the coast in salty water,” researchers said in a press release.
The presence of mangrove forests strongly indicates higher sea level and an increase of salt in the otherwise freshwater peatland ecosystem. Salt causes vegetation to dry. Imagine that in traditional ways of preserving food, salt helps to absorb water content, causing it to dry. The same happens to dry or dead trees in areas waterlogged with salt water, and these “mangrove woods are high-quality fuels that can burn for a long time and reach high temperatures,” explained the study.
Hapsari told tanahair.net this week, that their research suggests “salt-related damages and dieback of peat swamp forest or other freshwater inland vegetation could lead to massive forest fire once it is ignited and will result in large amounts of carbon release,” referring to a condition when the tree stands or forest vegetation are ill or dying due to various reasons, including drought and parasites.
She said that the best way to anticipate the potential disaster of increasing fires in coastal areas, is to prevent the sea surface level from rising further. This means that there needs to be a concerted effort to take action in reducing our carbon emission and curb further warming of the earth. Failing to do so could “potentially derail not only the Indonesian commitment to reduce their carbon emission, but also deforestation or forest loss rate”, she said.
In order to anticipate the worst-case scenario, the University of Göttingen recommended that land managers or local stakeholders refine and intensify existing fire hazard and risk reduction strategies on the coastal areas and start to develop saltwater intrusion vulnerability assessment.