Climate change

Over the last few years there has been much to-do about climate change and associated rise in sea level. A sea level rise would be especially disastrous for the Netherlands. Only half of the dry surface would remain if the dikes break at the current sea level, let alone when sea levels rise. The climate change also causes more extreme events with rainfall. This is therefore a major concern for water management. As a result, water boards who are in charge of water management have started projects to make more space for the river. In this way more water is stored before it reaches the sea and flooding can be buffered. Interestingly this often goes together with the development of new wetlands and nature areas.

Not horizontal– The sea level itself is often used as a standard surface. We say that something lies ‘above or below sea level.’ However, the use of the sea level as a standard surface for determining height has a major disadvantage, since the sea level is not completely flat: it has a small inclination. This means that the sea level is higher in some places than others. This inclination can have different causes, such as the tide, the carioles force and atmospheric influences. The tides obviously influence the sea level, but also cause differentiation along the coast because the ebb and flood tides do not necessarily occur at the same time at different locations.

The carioles force is, simply put, a force which originates at the Earth’s surface due to the turning of the Earth. Because of this, a moving subject on the northern hemisphere may turn to the right, whereas a moving subject on the southern hemisphere may turn to the left. With flowing water, the carioles force causes a small inclination in clockwise direction, resulting in an uneven sea surface.

The atmospheric influences may also influence the sea level. Atmospheric influences include air pressure and wind. During a heavy storm for example, the sea level is not flat.

Rise of the sea level- The sea level has risen more than 120 meters since the peak of the last ice age 18,000 years ago. The bulk of that occurred earlier than 6000 years ago. From 3000 years ago to the beginning of the 19th century, the sea level has remained almost constant, rising at only 0.1-0.2 mm per year. Since 1900, the level has risen at 1-3 mm per year, and since 1992 satellite altimetry indicates an increased rate of about 3 mm per year.

Read more:

An Overview of Coastal Land Loss: With Emphasis on the South Eastern United States. Accessed on February 14, 2005.
Changes in the Earth's shorelines during the past 20,000 years caused by the deglaciation of the Late Pleistocene ice sheets
(http://www.pol.ac.uk/psmsl/palaeoshoreline_webpage/HTML/HOME.htm), from the Permanent Service for Mean Sea Level
Includes pictures of sea level for past 20,000 years based on Barbados coral records
(http://www.pol.ac.uk/psmsl/palaeoshoreline_webpage/HTML/Science.htm)
Global sea level change: Determination and interpretation (http://www.agu.org/revgeophys/dougla01/dougla01.html)
Sea level rise FAQ (1997)
(http://www.radix.net/~bobg/faqs/sea.level.faq.html)
The Global Sea Level Observing System (GLOSS)
(http://www.pol.ac.uk/psmsl/programmes/gloss.info.html)