Rising sea levels linked to climate change pose a range of threats to islands and low-lying coastal areas.
Rising seas threaten human health, livelihoods and physical infrastructure all around the world.
The sea can rise and fall for many reasons but climate change is now thought to be causing a general increase in sea levels in two ways.
First, warmer water takes up more space than cooler water, and as our planet warms this is making the sea level rise.
The chair of the Intergovernmental Panel on Climate Change (IPCC), Rajendra Pachauri said in 2007 that a two-degree rise in temperature above pre-industrial levels would cause seas to rise by 0.4 to 1.4 metres due to this thermal expansion of water alone.
Second, rising temperatures are also causing glaciers and ice sheets to melt, adding to the total amount of water in the world’s oceans.
The 2007 IPCC report suggested that sea levels could rise by 19 to 59 cm by 2100, depending on different scenarios for future greenhouse gas emissions.
More recent scientific assements suggest a larger increase is likely, making adaptation to climate change more urgent.
This raises the risk of coastal erosion and floods – which can cause immediate physical damage and injury, threaten health with water-borne diseases, and contaminate drinking water and agricultural land with salt.
Small islands and low-lying areas of countries such as Bangladesh and Vietnam are especially at risk, but this is a worldwide problem. One-in-ten of all people on Earth — some 634 million — live less than ten metres above sea level.
ALTERNATIVES / SOLUTIONS
In the short to medium term, countries and communities need to adapt to rising seas by building sea defenses such as walls and dykes, moving people away from coastal areas and developing early warning systems to alert people of storms and sea surges.
Other ways to adapt include switching to salt-tolerant crops and raising the height of wells to protect them from flood waters.
Ultimately, for people living in some very low-lying places such as the Maldives and Tuvalu, migration to other countries may be the only way to adapt.
Rising seas threaten to cause very costly damage and one way to deal with this is through index-based insurance (see Adaptation to Climate Change).
Over the long term, scientists warn that the only way to limit sea level rise will be to drastically reduce emissions of the greenhouse gases that are warming the planet.
The science of sea levels is far from fixed and journalists need to be cautious about reporting unsubstantiated claims. This is uncertainty, for instance, about what contribution melting ice will make – and when.
In 2007 a British judge ruled that US vice-president Al Gore was scientifically inaccurate when he claimed in the film An Inconvenient Truth that melting of either west Antarctica or Greenland would cause a sea level rise of up to 7 metres in the near future.
Journalists should take care to assess the quality of any claims about the extent of sea level rise. Has the research been published in a peer-reviewed journal? What do independent scientists who also study sea levels say?
It is also important to remember that sea levels can rise for reasons unconnected to climate change, such as vertical land movements and changes in local weather conditions.
While reporting on impacts and potential impacts of sea level rise, journalists can enhance stories by reporting on ways to adapt. Local adaptation strategies from one part of the world may be applicable in very different settings.
Large amounts of finance for adaptation should soon be flowing from developed to developing nations. Journalists should be familiar with this climate finance and understand how it can be accessed to fund adaptation projects.
Story angles include investigations of whether coastal planning has taken account of rising sea levels, what authorities are doing to adapt, and how insurance companies are responding to the risk.
A good source for journalists is the Many Strong Voices coalition, which focuses on the impacts of climate change on coastal communities in the Arctic and small island developing states.
CASE STUDIES – Responses to rising tides
People in the Carteret Islands, Papua New Guinea, have often been portrayed in the media as the world’s first climate-change exiles, as it is feared that the islands will soon become uninhabitable.
Communities there have been struggling for years against rising seas. Waves are eroding the coastline, flooding vegetable gardens and destroying houses.
Already some of the islanders have migrated away from their homeland as related in this video interview with local community leader.
As journalist Greg Roberts reported in the Sydney Morning Herald, however, some people think that the islands are actually sinking, or that they are more prone to wave action because islanders destroyed protective coral reefs when using dynamite to fish.
LINKS TO TOOLKIT GLOSSARY
Integrated Coastal Zone Management
Alliance of Small Island States
Intergovernmental Panel on Climate Change
IPCC predictions of sea level rise according to different emissions scenarios
Climate change: study maps those at greatest risk from cyclones and rising seas