Climate change increases threats in South West Pacific

10 November 2021

Sea surface temperatures and ocean heat in parts of the South-West Pacific are increasing at more than three times the global average rate, with marine heatwaves bleaching once vibrant coral reefs and threatening vital ecosystems upon which the region depends.

Glasgow, 10 November 2021 (WMO) - Sea surface temperatures and ocean heat in parts of the South-West Pacific are increasing at more than three times the global average rate, with marine heatwaves bleaching once vibrant coral reefs and threatening vital ecosystems upon which the region depends.

On land, storms and floods routinely trigger death, destruction and displacement in South East Asia and Pacific Small Island Developing States (SIDS) whilst 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 a new report from the World Meteorological Organization (WMO).

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 South East Asia (including Brunei Darussalam, Indonesia, Malaysia, Philippines, Singapore) and Oceania (including Australia, New Zealand and Pacific Islands. It is one of a new series of regional climate reports by WMO and the first of its kind for the region.

The report and an accompanying story map was launched at the United Nations Climate Change negotiations, COP26, on 10 November. The existential threat to many Small Island Developing States (SIDS) is one of the recurrent themes at COP26, which is described as a make-or-break effort to achieve the Paris Agreement targets of limiting global temperature increase to a maximum of 2 degrees Celsius above pre-industrial levels.

“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,” said WMO Secretary-General Prof. Petteri Taalas.

“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 socio-economic development in the region, affecting key drivers of growth and revealing gaps in countries’ capacities for addressing systemic and cascading risk,” said Prof. Taalas.

Key messages


South-West Pacific land and ocean difference

In the South-West Pacific region, 2020 was the second or third warmest year on record, depending on the data set. A cooling La Niña event developed in the second half of 2020, but this is likely to have a greater impact on 2021 temperatures.

Sea surface temperatures are an important physical indicator of Earth’s climate system.  The ocean area of the South-West Pacific region is influenced by natural phenomena such as El Niño/La Niña as well as human-induced climate change. Between 1982-2020, ocean surface temperatures in the Tasman Sea and in the west of the Timor Sea increased at three times the global average rate.

Ocean warming

Ocean heat content

The ocean absorbs more than 90% of the excess heat from human activities. Since 1993, the global rate of ocean warming has likely more than doubled, and it will continue throughout this century. In parts of the South-West Pacific region, 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, 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.

Ocean warming, deoxygenation and acidification are changing the oceans’ circulation pattern and chemistry. Fish and zooplankton are migrating to higher latitudes and changing behaviours. 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

Sea-level trends from 1993 to 2020

Sea-level trends from 1993 to 2020. The coloured frames indicate the regions where
the coastal sea-level time series (see the figures to follow) are computed. Source: Copernicus Climate Change Service (C3S)

Global mean sea level has risen at an average rate of about 3.3 mm 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.

The North Indian Ocean and in the western part of the tropical Pacific Ocean, the rates of sea-level change are substantially higher than the global mean rise, mainly due to geographical variations in thermal expansion. Sea-level is also dependent on natural phenomena such as ENSO.

Sea-level rise is already having a major impact on society, economies and ecosystems in Pacific Islands. It also increases vulnerability to tropical cyclones, storm surge and coastal flooding.

Tropical Glaciers

The glaciers near Puncak Jaya, in Papua, Indonesia (4 884 m) are last remaining tropical glaciers between the Himalayas and the Andes, and have existed for around 5 000 years. At the current rate, total ice loss will be expected within the next five years – especially if there is a strong warming El Niño event.

Extreme weather

Storms and floods have historically been the most devastating extreme weather events in the region. The Philippines and Small Island Developing States have suffered greatly from regular typhoons/tropical cyclones. Droughts are also a major hazard.

In April 2020, 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. Typhoon Goni (Rolly) had one of the most intense landfalls of any tropical cyclone on record when it reached the Philippines on 30 October.

The unprecedented 2019–2020 wildfire season in eastern Australia led to severe smoke pollution. More than 10 million hectares were burned, 33 people were killed, more than 3 000 homes were destroyed and millions of animals died.

In January, Western Sydney, reached 48.9 °C – 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

Total Annual average losses from climate-related hazards in the South-West Pacific

Total Annual average losses from climate-related hazards in the South-West Pacific. Data sourced from ESCAP, 2021: The Risk and Resilience Portal.

Weather-related hazards continue to threaten the sustainable development of countries in the South-West Pacific and many of these are expected to become more extreme as a result 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 South-West Pacific is estimated to be US$ 28.1 billion in Indonesia, US$ 19.6 billion in the Philippines, US$ 14.8 billion in Australia and US$ 7.1 billion in Malaysia.

When the size of the economy is considered, 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

Adaptation and Resilience

Early Warning Systems are a key adaptation measure to reduce climate related risks and impacts. About three quarters of countries in South-West Pacific have a multi-hazard early warning system in place, representing approximately 73 000 in 100 000 people. Activities under the Climate Risk and Early Warning System (CREWS) initiative are seeking to strengthen this further.

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

The World Meteorological Organization is the United Nations System’s authoritative voice
on Weather, Climate and Water

For further information contact: Clare Nullis, media officer. Email Mobile phone: +41 79 709 13 97

Related Topics: