Sea Level Rise and the Pacific Island Region

Master of Sustainability Candidate Tong Wu, explores how Anthropogenic climate change, relative sea level rise, and vertical land movement will impact the Pacific Island region and its people.

Image via Shutterstock

Global warming has resulted in rapid sea-level rise in recent years, and seas will continue to rise as the effects of climate change become direr.

Greenhouse gas emissions are the primary cause for Anthropogenic climate change. The rise of ocean temperatures as a result of climate change is causing land based glacier ice to melt, resulting in the expansion of ocean water in the phenomenon of global sea level rise. While patterns of sea level rise and decline have changed throughout Earth’s history, relative sea level rise has traditionally been caused by nature. The past 200 years of human exploitation of underground resources such as groundwater, natural gas, oil and solid minerals, have had a greater impact on contributing to relative sea-level rise than ever recorded in human history. Furthermore, Nicholls and Cazenave (2010) highlight that climate change is also causing significant changes to vertical land movements; a phenomenon of subsurface land moving upwards, or the subsidence or sinking of land as oceans rise. Vertical land movement around the globe is not homogenous, and how a region experiences sea level rise is dependent on their locality (see Figure 1 below for an indication of the regions who are most at risk of sea level rise).

Figure 1: Vulnerable regions to coastal flooding (Nicholls and Cazenave, 2010)

For instance, Shanghai coast has subsided by up to 3 meters, while the coast in Tokyo has subsided by up to 5 meters (Nicholls et al., 2008). The direct impacts of sea-level rise are submergence, flooding and saltwater intrusion (Nicholls and Cazenave, 2010).

Climate change will directly threaten the lives of people living in coastal areas around the world, but the effects of climate change will not impact regions of the planet and people distinctly. Currently, a great number of Pacific Islanders are fighting for survival as climate change is having severe impacts on their coastal environments and ways of life. There is an urgent need for global residents to focus on how climate change and our changing oceans are having on the Pacific Islands regions.

For the people living in the Pacific, the effects are real (The world Bank, 2013). Approximately 41 tropical cyclones with earthquakes closely behind occur each year in the Pacific Islands, which cause severe environmental damage and economic loss (The World Bank, 2013). These natural disasters contribute to further land erosion, which further impact on people’s ability relocate. Vidal (2013) explains that the island country of Tuvalu in the Western Pacific, is likely to be underwater in the coming years.

The Marshall Islands located between Hawai’i and Australia, consist of 29 atolls and coral islands with average altitude of 2 meters (Vidal, 2013). In 2013, the capital almost was destroyed by a freak tide, while 6000 residents only had less than one liter of water per day because of the drought (Vidal, 2013). Anote Tong, the president of Kiribati, explains that further seawater encroachment would contribute to flooding and freshwater contamination, and would result in Kiribati being uninhabitable for its people (Vidal, 2013).

If we are to reduce the damage to coastal regions, we must take actions to respond to sea-level rise on a global level. Coastal areas need water management infrastructure and substantial flood defense to avoid flooding and submergence (Nicholls and Cazenave, 2010). However, it is a severe challenge especially for developing countries. Poverty and socioeconomic disadvantage mean that Pacific Island countries have a limited ability to respond to natural disasters, and are highly vulnerable to climate change (The world Bank, 2013). To assist in making the region resilient to the oncoming effects of climate change, there needs to be significant investments from developed countries and international organisations. For example, the World Bank supports the Samoa’s construction of climate resilient transport infrastructure, establishment of seawalls and planting mangroves in Kiribati (The World Bank, 2013). For responding to climate change, the World Bank invested over $120 million to Pacific Island Forum countries (The World Bank, 2013). Even though from 1990 to 2100, the global sea-level rise is estimated to be between 9 and 88 cm, it still remains a large range of uncertainty due to the concentrations of greenhouse gas in the future (Church et al., 2001).

Through a global response to reducing global warming, the sea-level rise could be controlled and contribute to protecting-the coastal residents of the Pacific, their homes, culture and ways of life.


Tong Wu is a Masters of Sustainability Candidate at the University of Sydney and holds a degree in Architecture from the University of Liverpool.