Sea-level riseSea-level rise

• The rise in the twentieth century • Satellite measurements

• Geographical differences• Forecasts

• Simulation 2050• Conclusion

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The rise in the The rise in the twentieth centurytwentieth century

• The latest IPCC reports, based on the records of The latest IPCC reports, based on the records of many coastal stations, conclude that the sea many coastal stations, conclude that the sea level is about 18 centimetres higher than in the level is about 18 centimetres higher than in the past century (between 1.5 and 2mm / year).past century (between 1.5 and 2mm / year).

• Failure to take into account the slow geological Failure to take into account the slow geological

movements that change the configuration of the movements that change the configuration of the oceans, sea level can rise for two main reasons: oceans, sea level can rise for two main reasons: and increase in ocean mass from melting and an and increase in ocean mass from melting and an increase of continental volume by thermal increase of continental volume by thermal expansion of oceans and decreased water expansion of oceans and decreased water density.density.

• The rise in the twentieth century of some 14 cm, was The rise in the twentieth century of some 14 cm, was due to changes in the water body, in the melting due to changes in the water body, in the melting continental. These figures should be taken with caution, continental. These figures should be taken with caution, because there are no well-known changes in the ice because there are no well-known changes in the ice covering Antarctica and Greenland and other glaciers. A covering Antarctica and Greenland and other glaciers. A type of calculation, based on changes in ocean salinity, type of calculation, based on changes in ocean salinity, indicates that the rise due to melting ice has been 6cm indicates that the rise due to melting ice has been 6cm during the twentieth century.during the twentieth century.

• Subtracting the 18 cm rise, 14 for thawing, warming the water would have been responsible for the rest of the increase: about 4 cm. This increase of 4 cm was calculated from measurements of temperature in seawater.

• During the period 1955-2003 a global ocean warming of 0.04 º C was deducted. This warming has not been uniform and continuous.

Satellite Satellite measurementsmeasurements

• Since 1992, the Topex-Poseidon satellite mission Since 1992, the Topex-Poseidon satellite mission estimated every ten days, the global average level of the estimated every ten days, the global average level of the sea surface. Their results so far indicate a general rise sea surface. Their results so far indicate a general rise quite strong.quite strong.

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Geographical Geographical differencesdifferences

   The change in sea level is geographically uneven.The change in sea level is geographically uneven.

Sea level variations (mm / year) during the period 1993-2003 in Sea level variations (mm / year) during the period 1993-2003 in various ocean regions of the planet, according to satellite various ocean regions of the planet, according to satellite measurements of the Topex-Poseidon missionmeasurements of the Topex-Poseidon mission..

ForecastsForecasts• With regard to the future the IPCC predictions With regard to the future the IPCC predictions

for 2100 reinforces the rise and estimates that for 2100 reinforces the rise and estimates that by then there will be an increase in the order of by then there will be an increase in the order of 50 cm (which would mean an average rate of 5 50 cm (which would mean an average rate of 5 mm / year, considerably higher than in the mm / year, considerably higher than in the twentieth century ).twentieth century ).

• But a more recent study, published in 2006, But a more recent study, published in 2006, specifies that in January 1870 to December specifies that in January 1870 to December 2004 the rise was 19.5 cm. This increase has 2004 the rise was 19.5 cm. This increase has been accelerating slightly with acceleration been accelerating slightly with acceleration calculated in 0,013 mm/año-2 therefore will calculated in 0,013 mm/año-2 therefore will continue to increase in 2100, between 28 cm continue to increase in 2100, between 28 cm and 34 cm.and 34 cm.

Simulation 2050Simulation 2050

Simulation of a given area shows to sea level rise due to Simulation of a given area shows to sea level rise due to

global warming.global warming.

In the picture there are several areas on the Andalusian In the picture there are several areas on the Andalusian coast, Atlantic and Mediterranean with a sea level rise of coast, Atlantic and Mediterranean with a sea level rise of 7 meters7 meters

ConclusionConclusion• Global Climate Change is a fact, although there are Global Climate Change is a fact, although there are

skeptics who are in no way a majority group. That is skeptics who are in no way a majority group. That is why governments around the world have reacted to why governments around the world have reacted to this growing threat of major climatic changes that this growing threat of major climatic changes that may put their economies at risk.may put their economies at risk.

• Global Climate Change, on the other hand, has made Global Climate Change, on the other hand, has made it very clear globalization of environmental it very clear globalization of environmental problems. It is impossible and pointless to confront problems. It is impossible and pointless to confront one of the most pressing environmental issues if all one of the most pressing environmental issues if all nations are not involved.nations are not involved.

The future of the world in our hands!

Help us!Help us!

• By: Andrea Suárez, María Rubio, Marta Montoro y Alba By: Andrea Suárez, María Rubio, Marta Montoro y Alba Mohedano.Mohedano.