海平面上升英文ppt

1、what causes the sea level to rise1. as air temperatures rise (due to climate change) the water in the oceans is warmed and expands. this process is called thermal expansion.2. as ice sheets and glaciers melt, they increase the amount of water in the oceans.consequences of the rise of sea levelsrisin

2、g sea levels put our coasts at rising sea levels put our coasts at riskriskroughly a third of the u.s. populationmore than 100 million peoplelive in coastal counties. coastal states with large areas of low-lying land, including louisiana, florida, north carolina, california, and south carolina, are

3、particularly vulnerable to rising seas and coastal storm surges. the risks to coastal states include:consequences of the rise of sea levelsshoreline erosion and shoreline erosion and degradation.degradation. rising sea levels allow waves to penetrate further inland, even during calm conditions, incr

4、easing the potential for erosion.consequences of the rise of sea levelsamplified storm amplified storm surges.surges. coastal storms often cause storm surges, which occur when high winds push water inland. with rising seas, storm surges occur on top of an elevated water level and reach farther inlan

5、d, with potentially catastrophic damage to homes and infrastructure.consequences of the rise of sea levelspermanent permanent inundation.inundation. many low-lying coastal land areas are expected to be gradually submerged by rising sea levels. a rise of two feet above todays sea level would put more

6、 than $1 trillion of property and structures in the u.s. at risk of inundation, with roughly half of that value concentrated in in florida.consequences of the rise of sea levelssaltwater intrusion.saltwater intrusion. saltwater can reach further into coastal groundwater sources as sea level rises, i

7、ncreasing the salinity of freshwater used for drinking and agriculture.my estimate for the sea to rise in china and around the worldlength records form the only direct evidence of glacier change that has potential global coverage before 1950. we calculate a globally representative signal from 349 gl

8、acier length records. by means of scaling, we deduce a global glacier volume signal, that is calibrated on the mass-balance and geodetic observations of the period 19502005. we find that the glacier contribution to sea-level rise was 8.4 2.1 cm for the period 18002005 and 9.1 2.3 cm for the period 1

9、8502005.my estimate for the sea to rise in china and around the worldthe central estimates for sea level rise in table 10.7 are smaller than the tar model means (church et al., 2001) by 0.03 to 0.07 m, depending on scenario, for two reasons. first, these projections are for 2090-2099, whereas the ta

10、r projections were for 2100. second, the tar included some small constant additional contributions to sea level rise which are omitted here (see below regarding permafrost). if the tar model means are adjusted for this, they are within 10% of the central estimates from table 10.7. (see appendix 10.a for further information.) for each scenario, the upper bound of sea level rise in table 10.7 is smaller than in the tar, and the lower bound is larger than in the tar. this is because the uncertainty on the sea level projection has been reduced, fo