Sea Level Rise

Questions 1.Why does water take up more space as it gets warmer? 2.Why does climate change raise sea levels? 3.How much has the ocean risen? 4.Why is melting in Greenland and Antarctica bad? 5.What are the effects of sea level change?

Reminder About 70% of the Earth's surface is water-covered – The oceans hold about 96.5% of all Earth's water – Other water is stored in glaciers and groundwater

Rising Sea Levels As water gets warmer, it takes up more space. – Each drop of water only expands by a little bit, but multiplied over the entire depth of the ocean, it adds up and causes ocean levels to rise. – Sea level is also rising because melting glaciers and ice sheets are adding more water to the oceans.

Climate Change The main cause of sea level rise is climate change – Greatly influenced by greenhouse gases A warmer climate does 2 things: – Melt ice sheets and glaciers – Cause water to heat up an expand

Changes in Temperature, Sea Level and Northern Hemisphere Snow Cover Courtesy of IPCC, 2007

What’s going on now Over the past 100 years, the average sea level around the world rose by nearly 7 inches

Greenland and the Antarctic The melting of Greenland’s and Antarctic ice sheets are particularly dangerous – The ice from the land flows into the water, raising the overall ocean level – Ice that is already in the ocean that’s melting won’t raise the sea level

The loss poses grave environmental dangers … but not Sea Level Rise Summer 1979 Summer 2003 Arctic Sea Ice Is Disappearing At Record Rate

10 Global change - More ice on land = Lower sea level

Sources of Ice Melt & Potential Impact on Sea Level 70 m Antarctica 6 m Greenland 0.7 m Mountain Glaciers

Changes in sea levels During the last Ice Age (10,000 years ago), global sea levels were 130 meters (425 feet) lower than current day – Glacial melting has raised the level of the ocean Every year, the ocean rises mm

The Future If our climate keeps getting warmer, the average sea level around the world by the end of this century (the year 2099) could be anywhere from 7 to 23 inches higher than it was in – Sea level could rise even more if the big ice sheets in Greenland and Antarctica melt faster.

Effects of Rising Waters

Effects of Sea Level Change No matter the cause, rising ocean levels can cause great damage – Beaches are eroded – Flooding Netherlands, many islands, all of Florida and Louisiana would be underwater Cities would disappear – New York! – Increased salinity of rivers, bays, and groundwater table Estuaries would be destroyed Drinking water would be ruined

Sea level rise: Fraser Valley scenarios North America current Source:

Sea level rise: Fraser Valley scenarios North America: 1 metre sea level rise

Sea level rise: Fraser Valley scenarios Africa, Asia, Europe: 1 metre rise

Sea level rise: Fraser Valley scenarios Africa, Asia, Europe: 6 meter rise

Sea level rise: Fraser Valley scenarios Coastal futures : New Orleans & Katrina