A new report from the World Meteorological Organization (WMO) has found that sea surface temperatures and ocean heat in parts of the Southwest Pacific are increasing at more than three times the global average rate, causing marine heatwaves to bleach once vibrant coral reefs and threaten ecosystems upon which the region depends.
The report, The State of the Climate in the South-west Pacific 2020, provides a snapshot of climate indicators like temperatures, sea level rise, ocean heat and acidification and extreme weather, alongside risks and impacts on economies, society and the environment. It covers much of Southeast Asia (including Brunei Darussalam, Indonesia, Malaysia, Philippines, Singapore) and Oceania (including Australia, New Zealand and Pacific Islands.
The report found that on land, storms and floods routinely trigger death, destruction and displacement in Southeast Asia and Pacific Small Island Developing States (SIDS) while extreme heat and a more intense fire season are expected to become a feature of Australia’s climate. Tropical glaciers – the last remaining ones between the Himalayas and the Andes – may disappear within five years, according to the report. The existential threat to many SIDS was one of the recurrent themes at COP26, which was described as a make-or-break effort to achieve the Paris Agreement targets of limiting global temperature increase to a maximum of 2°C above pre-industrial levels.
Prof. Petteri Taalas, WMO secretary-general, said, “This report highlights the real and potential risks associated with the changes occurring in ocean circulation, temperature, acidification and deoxygenation, as well as rising sea level. The Small Island Developing States are increasingly vulnerable to these changes, as their incomes are highly linked to fisheries, aquaculture and tourism.
“Over land areas, the significant and growing impacts of extreme hydrometeorological phenomena and tropical cyclones, plus new multi-dimensional threats, pose increasing
challenges to communities in the region. The Covid-19 pandemic has disrupted socioeconomic development in the region, affecting key drivers of growth and revealing gaps in countries’ capacities for addressing systemic and cascading risk.”
Overall, the report highlighted temperature, ocean warming, sea-level rise, tropical glaciers, extreme weather and their impacts as well as adaptation and resilience.
While drawing attention to the fact that the Southwest Pacific Ocean is influenced by natural phenomena such as El Niño/La Niña as well as human-induced climate change, the report highlighted that ocean surface temperatures in the Tasman Sea and in the west of the Timor Sea increased at three times the global average rate from 1982-2020. Overall, the data set used found that 2020 was the second or third warmest year on record. (A cooling La Niña event developed in the second half of 2020, but this is likely to have a greater impact on 2021 temperatures.)
In terms of global ocean warming, the report estimates that the rate of ocean warming has more than doubled since 1993 and it will continue to do so throughout this century. This is likely to be because the ocean absorbs more than 90% of the excess heat from human activities.
In parts of the Southwest Pacific region specifically, ocean heat content has increased more than three times faster than the global average rate. In 2020, the Great Barrier Reef region of Australia suffered a major heatwave. In February, sea surface temperatures over the region were 1.2°C above the 1961–1990 average, making it the hottest month on record. High temperatures affected the entire reef and widespread coral bleaching was reported, making it the third mass bleaching event in the past five years. If global temperature rises 2°C above pre-industrial levels, there is a risk that 90% of the coral reefs in the Coral Triangle and the Great Barrier Reef could face severe degradation.
Additionally, ocean warming, deoxygenation and acidification are changing the oceans’ circulation pattern and chemistry. Fish and zooplankton are migrating to higher latitudes and changing behaviors. Consequently, traditional fisheries are altering. This has critical implications for the Pacific islands where coastal fishing is a principal activity that provides for nutrition, welfare, culture and employment. Between 1990 and 2018, total fisheries production has decreased by as much as 75% in Vanuatu, 23% in Tonga and 15% in New Caledonia.
Sea level rise
When looking at sea level rise, the report found that global mean sea level has risen at an average rate of about 3.3mm per year since the start of satellite records in the early 1990s and has accelerated as a result of ocean warming and land-ice melt. In the North Indian Ocean and the western part of the tropical Pacific Ocean, the rates of sea-level change are substantially higher than the global mean rise. This was found to be primarily due to geographical variations in thermal expansion and natural phenomena such as ENSO. In the report, the researchers pointed to the major impact that sea-level already has on society, economies and ecosystems in Pacific Islands as it increases vulnerability to tropical cyclones, storm surge and coastal flooding.
The glaciers near Puncak Jaya, in Papua, Indonesia (4,884m) are the last remaining tropical glaciers between the Himalayas and the Andes and have existed for around 5,000 years. At the current rate, the total ice loss will be expected within the next five years, especially if there is a strong warming El Niño event, the report said.
Storms and floods have historically been the most devastating extreme weather events in the region. The report reviewed the events that occurred in the Philippines and SIDS which suffered greatly from regular typhoons/tropical cyclones as well as droughts.
In April 2020, the category 5 tropical cyclone Harold led to extensive human and economic damage in the Solomon Islands, Vanuatu, Fiji and Tonga. The Philippines was devastated by consecutive tropical cyclones during October and November 2020. Similarly, typhoon Goni (Rolly) had one of the most intense landfalls of any tropical cyclone on record when it reached the Philippines on October 30.
On the other end of the scale, the WMO report found that the unprecedented 2019-2020 wildfire season in eastern Australia led to severe smoke pollution. More than 10,000,000ha were burned, 33 people were killed, more than 3,000 homes were destroyed and millions of animals died. In particular, Western Sydney reached 48.9°C in January 2021, the highest temperature on record for any major Australian metropolitan area; and Canberra reached 44.0°C – more than one degree above the city’s previous record. Australian land areas have warmed by around 1.4°C since 1910 – above the global average.
Impacts of extreme weather
The report found that the impact of this extreme weather and weather-related hazards not only threatens the sustainable development of countries in the Southwest Pacific but can also be expected to become more extreme because of climate change. An increase in the intensity of typhoons is likely in regions of the western North Pacific near the Philippines.
Between 2000 and 2019, about 1,500 fatalities occurred and close to 8 million people were affected during extreme weather events per year on average in the region. In 2020, there were about 500 fatalities, about one-third of the long-term annual average, but more than 11 million people were affected, mainly by tropical cyclones. The Philippines and Indonesia typically report large numbers of affected people from extreme weather events. However, Pacific islands suffer disproportionately when the size of the population is taken into consideration. In Vanuatu and Fiji, more than one-fifth of their populations were affected in 2020 by tropical cyclones.
The average annual loss (AAL) from extreme weather events across the Southwest Pacific is estimated to be US$28.1bn in Indonesia, US$19.6bn in the Philippines, US$14.8bn in Australia and US$7.1bn in Malaysia. As the report considered the size of the economy, it found that the estimated AAL is as high as 17.9% of GDP for Vanuatu, 14.6% of GDP for Tonga and 7.7% of GDP for the Federated States of Micronesia.
Adaptation and Resilience
As a result of these findings, the report emphasized that early warning systems are a key adaptation measure to reduce climate-related risks and impacts. About three-quarters of countries in Southwest Pacific have a multi-hazard early warning system in place, representing approximately 73,000 in 100,000 people. Therefore, activities under the Climate Risk and Early Warning System (CREWS) initiative are seeking to strengthen this further.
The State of the Climate in the South-west Pacific 2020 concluded that addressing the rising climate risks and associated impacts requires local, regional and transnational capacity building, development of climate services and integrated disaster risk reduction approaches. These constitute foundational elements for achieving the 2030 Agenda for Sustainable Development and building back better from the Covid-19 pandemic.