How will climate change impact Malaysia? Part 2

A 1 to 3 degrees Celsius difference probably doesn’t mean much to us in the short term, but the impact is huge over the long term.

To quote from Bill Gates in his new book on climate change, the average temperature in the last ice age was just 6 degrees Celsius lower than it is today, and dinosaurs were alive (with crocodiles swimming in the Arctic) when average temperatures were around 4 degrees Celsius higher than today.

In part 2 of my reading of Malaysia’s National Communications reporting to the UNFCCC (see part 1 here), I’m going to highlight the projected impact (or vulnerability assessments) of climate change in Malaysia.

Quick questions:

Is this just happening in Malaysia?

No. The average global temperature has increased at the fastest rate in recorded history in the past 50 years and the trend is accelerating.

Why do GHG emissions cause global average temperatures to go up?

GHG like carbon dioxide and methane absorb sunlight and solar radiation in the atmosphere. This keeps the earth warm. The problem is when there is too much of GHG up there, trapping the heat in Earth.

Why does global warming cause more intense rainfall and dry spells or extreme weather events?

1. Higher temperatures increase the rate of evaporation from the ocean and other water bodies.
2. Warmer air can hold more moisture.
3. As a result, there is a drier condition on land.
4. When the air cools down, the evaporated water becomes rain or snow. The intensity of rainfall depends on how much moisture is held in the air. If it’s a lot, then you can expect a heavy rain.
5. Changing air temperatures and circulation patterns will also result in different regions getting different kinds of weather events.

Why does global warming result in sea level rise?

Glaciers and ice sheets are melting due to global warming, thus adding water to the ocean. The volume of the ocean also expands with higher temperature. Melting of glaciers and ice sheets have accelerated over the past few decades.

Hotter & rain-ier

1. Average air temperature for the country may increase by 0.5 to 1 degrees Celsius by 2030, and may increase by 0.9 to 1.6 degrees Celsius by 2050.
2. All regions show increment of rainfall amount by 2030, except for west coast of Sabah, which will see reduction by 3.9%. Most increment of rainfall will be seen in southern Sarawak, central region and southern region in Peninsular Malaysia.

Flooding and drought

1. Over the last decade, more weather extremes have been occurring in the country.
2. Major flooding occurred in 2010, 2012 and 2014, with the 2014 northeast monsoon floods being one of the worst recorded in history. A very strong El Nino occurred in 2016, which resulted in prolonged dry periods and associated water shortages, heat waves and wild fires.
3. 144 out of 191 river basins in Malaysia are prone to flood. Among 14 of these flood-prone basins, Batu Pahat Basin shows highest increment of total flood prone area, followed by Kelantan Basin.
4. Most severe dry spells are projected to occur between 2025 and 2035 in Peninsular Malaysia, and between 2045 and 2055 in East Malaysia.

Sea level rise

1. West Coast of Peninsular Malaysia is projected to experience a maximum sea level rise of 0.05–0.10 m by 2030 and 0.11–0.21 m by 2050.
2. East Coast of Peninsular Malaysia is projected to experience maximum sea level rise of 0.07 m by 2030 and 0.11–0.15 m by 2050.
3. Sabah and Sarawak are projected to experience maximum sea level rise at 0.11–0.15 m and 0.04–0.12 m by 2030, and 0.21–0.62 m and 0.15–0.22 m by 2050.

Dams, groundwater and coastal erosion

1. Heavy rainfall can result in more frequent critical dam levels and subsequent downstream flooding. This occurred in 2013 and 2014, as well as 2006 and 2007.
2. This situation is expected to worsen with the future average annual rainfall projected to rise by 31.5% and average annual mean river flow to rise by 36% by 2100.
3. A formal dam safety inspection conducted on Klang Gates Dam shows that dam overtopping could occur if climate change factor is included in the analysis. (We have 93 dams in Malaysia, 57 of which provide water supply. The rest are for hydroelectric, flood mitigation etc — 2013)
4. Dry spells can result in water storage level of dams to fall below the 50% warning level consecutively for a few months. This occurred in 2014, 2015 and 2016 and is expected to occur more frequently in the future.
5. Ground water faces the threat of saltwater intrusion to the aquifers. Preliminary assessment indicates that several tube wells in Sabah and Sarawak may be vulnerable to sea level rise in 2030 and 2050. (In 2010, groundwater use is equal to approximately 3.4% of total water consumption in the country. Kelantan is the biggest user, where 40% of potable water supply comes from groundwater.)
6. Of the total coastline of 8,840 km in Malaysia (31% of population of Peninsular Malaysia live and work here), 1,346.3 km (15%) are continuously being eroded. Of these, 55.4km are under the critical erosion category. 37 out of 344 areas under critical and significant erosion categories are at risk of sea level rise by 2030.

Food security and agriculture

1. The major rice granary areas in Peninsular Malaysia may face average rice yield production reductions of 6% to 13% between 2030 and 2050, due to higher average daily temperatures.
2. Malaysia has a self-imposed rice self-sufficiency of about 71.6%. 74% of the country’s rice production is contributed by 10 main granary areas, including Muda Agricultural Development Authority (MADA), Kemubu Agricultural Development Authority (KADA) and Integrated Agricultural Development Authority (IADA).
3. Based on simulation models for 2030 and 2050, IADA-Barat Laut Selangor faces most significant reduction of yield over 30% over the main season in 2030. KADA is most prone to flooding. Dry spells are known to affect MADA, which is also vulnerable to sea level rise or seawater intrusion due to its location at low-lying coastal plains.
4. Assessment of flood risks of oil palm areas planted in 15 flood prone basins in Peninsular Malaysia indicates that areas affected will increase by 85% and 460% in 2030 and 2050.
5. Extreme dry spells are expected to occur and negatively affect yield of rubber by up to 18% to 20%. (90% of total rubber planters are smallholders)
6. Local dairy production would be reduced by over 25% due to severe heat stress.

Khazanah Research Institute

Diseases galore

1. Dengue, Malaria, food and water borne diseases like Cholera and Typhoid, and chronic non-communicable diseases sensitive to air pollution and heat are expected to be challenges as average temperatures rise.
2. Dengue epidemics in Malaysia have been observed to occur every 5 to 8 years and have been increasing since 2001.
3. There is evidence that a warming trend over past decades has enhanced the presence, survival and vectorial capacity of malaria vectors, increasing the probability of malaria transmission and highland epidemics.
4. Extreme weather events may cause food and water borne diseases to become widespread as it is a triggering factor.

Forestry and biodiversity

1. Mangrove forests may be susceptible to sea level rise and salt water intrusion. (However, it currently faces greater threat from habitat loss.)
2. During prolonged dry spells and temperature rise, reduced growth rates of forests are observed.
3. Coral reefs are affected by temperature increases, especially during El Nino episodes where over 40% of corals die through coral bleaching. (In 1998, an estimated 40% of corals in reefs around Peninsular Malaysia died. Coral bleaching also occurred in 2010, 2014, 2015 and 2016.)
4. Drained peat swamp forests are more susceptible to forest fires, which occurs more frequently during dry seasons.
5. Research has documented that various species of moth native to Mt Kinabalu have been moving their ranges uphill due to temperature rise.
6. It is likely that most birds, amphibians and reptiles in Malaysia may move to higher altitudes with climate change temperature increase.