The Ocean, our climate and weather

The Ocean, our climate and weather

23 Mar 2021

Bangkok, Thailand

By Dr. Senaka Basnayake and Lalit Kumar Dashora

The Ocean and Climate:

The ocean and climate are inextricably interrelated. The ocean plays a significant role in Earth’s environment. One of its largest contributions is to absorb energy (heat) and distribute it more evenly throughout the Earth. The ocean also helps to absorb Earth’s CO2 (NOAA, n.d.), covers 70% of the Earth's surface and has a significant impact on the Earth's weather and climate.

On a local to global scale, oceans influence the short-term weather patterns to long-term climate variability and climate change. The interaction of oceanic and atmospheric processes controls Earth’s weather and climate (NOAA, n.d).

For example, the heat transferred from the tropical ocean provides the energy that drives atmospheric circulation, including hurricanes, cyclones, and polar storms. The ocean exchanges heat, moisture, and carbon with the atmosphere on a continuous basis, affecting our weather patterns and the slow, subtle changes in our environment. Ocean water evaporates steadily, raising the temperature and humidity of the surrounding air, resulting in rain and storms carried by trade winds. In fact, the ocean is the source of almost all rain that falls on land.

All places on the Earth have different climate. Climate describes the average weather conditions of a particular location over a 30-year period. The weather we experience hourly and daily basis depends on where we reside on the Earth.

Places around the Equator experience warm weather all year round, but experience alternate periods of rainy and dry seasons. Places near oceans may experience more cyclone and storms, whereas places on continental plains may be more prone to hail, thunderstorms, and tornados in the summer. The different kinds of weather we might experience in these regions are caused by moving patterns in the Earth’s atmospheric and oceanic circulation, unequal heating of the Earth, and the rotation of the Earth on its tilted axis.

Island nations, the Ocean and weather and climate events:

The Pacific island states has a highly variable climate, which is heavily influenced by the El Niņo Southern Oscillation (ENSO). According to the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC), current and future climate-related drivers of risk for SIDS in the 21st century are sea level rise (SLR), tropical and extra-tropical cyclones, increasing air and sea surface temperatures, and changing rainfall patterns (Allen et al. 2014).

Current and projected climate change for the Pacific islands will increasingly impact the regions’ geophysical, biological and socio-economic systems, livelihood, food production, increased flood risk, salinization of water resources and in some areas permanent loss of land (Allen et al. 2014, Wing, 2017, Kumar et al., 2020).

The Pacific island states are generally small in size with a limited and narrow range of natural resources. Due to their small sizes, generally low elevations and isolation, they are highly vulnerable to natural hazard events. Many of them fall directly in the paths of tropical cyclones.

Floods, tropical cyclones, droughts and storm surges have become a part and parcel of these people. However, over many generations, inhabitants of these island states have adapted well to the natural hazard events that are quite regular and over which they have no control. The people of the Pacific have become accustomed to these, and now, such events are inseparable from their lives (Kumar et al. 2020).

Some of the Pacific island countries rank among the world’s worst affected by disasters. Climate change is a new entrant that is causing havoc in many small islands and is destroying lives and livelihoods.

This situation compounded due to climate change, the region is witnessing intense fluctuations in weather patterns, such as changing temperatures and precipitation patterns, severe storms and rising sea levels. Lack of economic diversification, remoteness from major trade centers and strong gender inequalities characterize many Pacific island nations and exacerbate their vulnerability to disasters.

Making island nations more climate and disaster resilient:

Regional organizations are well prepared to strengthen regional coordination in the Pacific on hazard detection and analytical services for a range of hazards, particularly meteorological services.

Both the Secretariat for the Pacific Regional Environment Programme (SPREP) and the Pacific Community (SPC) play a leadership role in managing weather and climate information in addition to obtaining and analysing geophysical information with other international and regional organizations such as UNDP, UNDRR, FAO.

The Pacific Islands Meteorological Strategy 2012-21 (PIMS Strategy) provides a mechanism for improved donor coordination on future EWS or MHEWS investments. There are clear objectives to enhance regional MHEWS capacity in the Strategy. SPREP manages the Strategy through the Pacific Meteorological Council (PMC). There may be scope to organize development partner communities of practice through the PMC, to ensure investments are coordinated.

At the global level, the World Meteorological Organization (WMO) provides a framework for coordination of National Meteorological and Hydrological Services (NMHS), setting standards and maintaining a regional center in Fiji. The ultimate aim of the WMO regional programme is to support NMHSs to provide weather, climate and water information services to the various socio-economic sectors in their countries, and also to contribute to the regional and global observation system.

Both international and regional organizations are trying to move towards integrated systems for early warning across the Pacific. Despite some positive steps, it is not clear how this will be achieved without stronger cross-institutional collaboration and a clearer definition of roles and mandates across regional organizations.

For example, SPC assists countries with geohazard and hydrological capacity building (flood, landslide, earthquake and tsunami), and coordinates disaster response activities, while SPREP provides significant leadership on climate and meteorological matters (climate change, drought, cyclone and storm surge). SPC also provides technical services to Pacific countries on a range of areas relevant to building capacity in MHEWS.

Under aegis of WMO, ADPC recently conducted a study to assess existing MHEWSs in seven selected Pacific Islands countries (including Cook Islands, Fiji, Kiribati, Nauru, Niue, Tokelau, and Tuvalu) to make recommendations for further advancement of MHEWSs to better prepare for future hazards.

Dr. Senaka Basnayake is Director of Climate Resilience Department and Director a.i. of Urban Resilience Department at ADPC.

Lalit Kumar Dashora is the Senior Early Warning Specialist at ADPC.