SEA LEVEL RAISE AND ITS EFFECTS

G.D. UMADEVI TAM/2014-03

Dept. of Agronomy

What is Sea level rising Earth’s climate is warming because of an increase in

the “greenhouse gases,” especially CO2, in the atmosphere. (See“Increasing Atmospheric Carbon Dioxide”and“Climate Change” in this series.) This warming is resulting in a melting of large planetary ice masses, such as glaciers, sea ice, and the polar ice caps.

Four contributions to sea level rise

1. Thermal expansion of seawater

2. Melting of glaciers and ice caps

3. Ice sheet surface mass balance• snowfall - melting

4. Ice sheet surface dynamical imbalance

• increased flow rate

2006 - IPCC estimate

1. Thermal expansion of seawater .......... 28 cm

2. Glaciers and ice caps ......................... 12 cm

3. Mass balance ..................................... - 3 cm

4. Increased flow ................................... + 3 cm

Total: 40 cm

Range of Estimates: 18-59 cm

How do we know this is happening?

Glaciers are not good indicators of recent global warming, as their melting and growing can significantly behind air temperatures.

A more reliable indicator measure is sea ice, which is frozen seawater floating on the surface of the ocean.

The largest single mass of sea ice is the Arctic (North Polar) Ice Cap.

An additional effect is that, as more ice and snow in the Arctic region melts, it changes the reflectance, shifting the regions from white to darker colors associated with land and sea surfaces.

As you can see in the melting snow of white sidewalk adjacent to blacktop, a darker surface will absorb heat and further speed up the warming of the Arctic.

Summer minimum ice, average of 2000-2003

Summer minimum ice, average of 1979-1981

Greenland is the largest island in the world, a sparsely populated self-governing division of Denmark. Figure 3 shows a cross-section of Greenland, with part of the ice cut away .Unlike the Arctic sea ice, this ice is sitting on rock, so when it melts, it raises the level of the ocean. Greenland is 2,650 km long (1,650 mi) and the ice is an average of about 2.5 kilometers thick (1.5 mi).

Greenland is melting

How much sea level rise?

Amounts of water in those planetary ice masses that would raise sea level.

Ice Masses Area (1000 sq km)

Volume(1000 cubic km)

Potential Sea Level Rise (m)

Mountain Glaciers and Small Ice Caps

680 180 0.45

Greenland 1785 2620 6.55

Antarctica (total) East Antarctica West Antarctica Antarctic Peninsula Ice Shelves

135861015319184471068

30110260393262227582

73.4464.808.060.460.12

Total 16051 32910 80.44

What are the Dangers of Sea Level Rise

Dangers that come as a result of sea level rise include flooding, coastal erosion, wetland and coastal plain flooding, salinisation of aquifers and soils, and a loss of homes for fish, birds, and other animals and plants.

Sea level rising is mainly caused by thermal expansion and the melting of glaciers and ice caps.

Check out the major effects of rising sea level on people and the environment

Coastal Areas Recreation Plants, Animals, and Ecosystems

Global climate change threatens coastlines and the buildings and cities located along them.

Hundreds of millions of people around the world live in low–lying areas near the coast that could be flooded as the sea level rises.

Rising sea level will also erode beaches and damage many coastal wetlands.

Rising sea level and stronger storms caused by warmer oceans could completely wipe out certain beaches and islands.

Coastal Areas

Major Floods

Coastal futures

Recreation In addition to causing all sorts of problems, such as

heat waves, droughts, and coastline damage, warmer temperatures could also affect people's jobs, recreational activities, and hobbies.

For example, in areas that usually experience cold winters, warmer temperatures could reduce opportunities for skiing, ice fishing, and other winter sports. Also, rising sea level could wash away beaches.

Plants, Animals, and Ecosystems

Any change in the climate of an area can affect the plants and animals living there, as well as the makeup of the entire ecosystem. Some species are already responding to a warmer climate by moving to cooler locations.

For example, some North American animals and plants are moving further north or to higher elevations to find suitable places to live. Climate change also alters the life cycles of plants and animals.

For example, as temperatures get warmer, many plants are starting to grow and bloom earlier in the spring and survive longer into the fall. Some animals are walking from hibernation sooner or migrating at different times, too.

Disappearing HabitatsPlants, Animals, and Ecosystems

Quonnie Pond: present sea level

Quonnie Pond: 3 ft. sea level rise

THANKYOU