Floods, hurricanes and ozone
GLOBAL warming is likely to jeopardise not only our seafood; it’s also linked to stronger hurricanes and floods.
This issue was discussed when several hurricanes hit the United States recently. It’s also a relevant issue for Malaysia.
As sea surfaces warm up, the frequency of hurricanes is not going to change much, but the intensity of hurricanes is going to go up, explained Prof Datuk Dr Azizan Abu Samah, director of the National Centre for Antarctic Research (NCAR).
He was speaking at a recent seminar organised by the Institute of Ocean and Earth Sciences (IOES) at Universiti Malaya, Kuala Lumpur.
Prof Azizan, who is also deputy director of IOES, showed a graph revealing how the intensity of hurricanes has spiked globally in the last 20 years.
In addition, we are also experiencing stronger winds and more intense rain these days.
“With higher sea surface temperatures, the atmosphere can take in more water vapour. And the fuel for hurricanes and thunderstorms is the vapour,” he said, adding that the Philippines has among the most hurricanes in the world.
Heavy rain followed by flooding happens annually along the east coast of Peninsular Malaysia during the North-East monsoon (November to February). In mid-December 2014, two episodes of extreme rainfall began, causing widespread flooding in Kelantan, Trengganu and Pahang.
What’s unusual was that these long-lasting “extreme rainfalls” were concentrated over the catchment areas in the (mountainous) upper reaches of the Kelantan and Pahang River basins, instead of near the lower reaches.
Available records show that these extreme meteorological events were the first to occur in Peninsular Malaysia.
‘Halo’ hits ozone
Global warming can also hit us in other unexpected ways.
It’s all connected; higher temperatures affect the amount of halocarbons released by algae which then contributes to ozone layer depletion.
“Loss of the protective ozone layer increases cases of cataracts and skin cancer in humans and animals, and also affects plant growth,” said Prof Dr Phang Siew Moi, director of IOES.
Halocarbons are chemical compounds capable of altering the chemical composition of gasses in the atmosphere. They affect local climate and also contribute to
global warming.
Marine algae (seaweeds and phytoplankton) produce halocarbons through the activities of certain enzymes. Seaweed, which thrive in the coastal region, produce around 70% of global bromoform (a type of halocarbon) while phytoplanktons are important sources of halocarbon in the open ocean.
Algae are now intensely exploited due to their pharmaceutical and nutraceutical properties, and as a food source.
“The Malaysian government has been interested in seaweed farming for potential agricultural development,” said Prof Phang.
However, these marine organisms produce halocarbons as a form of defence against predators and under stressful environmental conditions.
Most long-lived halocarbons (with an atmospheric lifetime of six months to hundreds of years) are man-made, while the marine environment is an important source of short-lived halocarbons.
Research at IOES focuses on understanding the interactions between halocarbon emissions from marine algae and climate change, and investigating the effects of environmental changes like temperature, irradiance (light levels) and ocean acidification on these emissions.
“The data generated will help us understand future climate scenarios in the region,” she said. —