PPT-30 G reen E arth M ovement

An E-Newsletter for the cause of Environment, Peace, Harmony and Justice

Remember - “you and I can decide the future”

RISING SEA LEVELS

Sea-level rise is one of the most concerning consequences associated with global climate change, thanks to melting polar ice and thermal expansion caused by warming ocean waters - and we're already starting to see its effects on coastal communities around the world.

Global average sea level rose roughly eight inches from 1880 - 2009.

The average annual rate of global sea level rise accelerated from 1993 - 2008, increasing 65 - 90 percent above the twentieth century average. The U.S. East Coast and Gulf of Mexico experienced some of the world's fastest rates of sea level rise in the twentieth century due to local and regional factors.

The US Geological Survey estimates that if all the world's glaciers melted, sea level would rise by about 80 meters, or more than 260 feet. This scenario could be thousands of years in the future, but it would render many of the world's best-loved coastal cities unrecognizable.

Global warming is the primary cause of current sea level rise. Human activities, such as burning coal and oil and cutting down tropical forests, have increased atmospheric concentrations of heat-trapping gases and caused the planet to warm by 1.4 degrees Fahrenheit since 1880.

Rising temperatures are warming ocean waters, which expand as the temperature increases. This thermal expansion was the main driver of global sea level rise for 75 - 100 years after the start of the Industrial Revolution, though its relative contribution has declined as the shrinking of land ice has accelerated.

Land ice—glaciers, ice caps, and ice sheets—is shrinking at a faster rate in response to rising temperatures, adding water to the world's oceans.

As the rate of ice loss has accelerated, its contribution to global sea level rise has increased from a little more than half of the total increase from 1993 - 2008 to 75 - 80 percent of the total increase between 2003 - 2007.

Sea level will rise significantly over the coming century. Our past heat-trapping emissions have committed us to continued sea level rise over the coming decades, but our present and future emissions choices can affect the rise in seas and the pace at which it unfolds beyond 2050.

As global temperatures continue to rise, ice in the polar regions and glaciers will melt, dumping tons of extra water into the ocean. Warmer water temperatures will also lead the oceans to expand.

These factors will cause sea levels to increase and swamp coastal areas all over the world.

Although flooding is the obvious consequence of rising sea levels, there are plenty of other effects to consider — none of them good.

Here are five of those effects you probably haven't thought about:

1. It will contaminate our drinking water As the rising sea crawls farther and farther up the shore, in many places it will seep into the freshwater sources in the ground that many coastal areas rely on for their drinking water. These underground water sources, called aquifers, are crucial springs of freshwater — in fact, groundwater accounts for most of the planet's freshwater.

Saltwater is unsafe to drink, and while it is possible to remove the salt from water, doing so is an expensive and complicated process. Some communities are already investing in costly desalination plants in anticipation of hard times ahead.

2. It will interfere with farming Those same freshwater sources we use for drinking also supply the water we use for irrigation. The problems here are the same: The intruding sea could make these groundwater sources saltier. Saltwater can stunt or even kill crops, but creating freshwater from saltwater is a costly and unsustainable practice.

In a twist of irony, recent research has suggested that pumping freshwater from the ground for human use may actually be contributing to a rise in sea levels. After the groundwater has been used — for drinking, irrigation, or other industrial purposes — it is often discarded into the ocean, where it adds to the already-growing volume of water lapping at our shores.

3. IT WILL CHANGE OUR COSTAL PLANT LIFE More saltwater hitting our shores will change the chemistry of the soil on the coast, meaning the plant life there will most likely change as well. Plants are really sensitive to their environments. Air temperature, access to water, and the chemical characteristics of soil are all factors that influence whether a plant can thrive in a given location. As rising ocean water seeps into the ground, the soil near the coast will become saltier. Some plants will simply be unable to cope with the change in soil salinity and may disappear from the shoreline.

Trees have to work harder to pull water out of salty soil; as a result, their growth can be stunted — and if the soil is salty enough, they will die, a common sign of sea level rise. Even trees that are especially suited to salty soil can't survive repeated flooding by seawater.

4. IT WILL THREATEN WILD LIFE POPULATIONS Many forms of wildlife make their home on the beach. As the rising ocean erodes the shoreline and floods the areas in which coastal animals live, animals like shorebirds and sea turtles will suffer. Their delicate nests may be swept away by flooding, an especially big problem for endangered animals like sea turtles that can't afford to lose any offspring. Their habitats may be so damaged by flooding or changes in the surrounding plant life that they can no longer survive in the environment.

5. It will hurt the economy The tourism and real-estate industries in coastal areas are likely to take a hit as prime beachfront properties and recreational areas are washed away by rising waters. This is a fact that some involved in these industries are finding hard to swallow.

Even if global warming emissions were to drop to zero by 2016, scientists project another 1.2 to 2.6 feet of global sea level rise by 2100 as oceans and land ice adjust to the changes we have already made to the atmosphere.

Projections for global sea level rise by 2100 range from 8 inches to 6.6 feet above 1992 levels, though the lowest end of this range is a simple extension of historic sea level rise—and recent data indicate this rate has nearly doubled in recent years.

The rate and magnitude of the loss of ice sheets, primarily in Greenland and West Antarctica, will have the greatest effect on long-term sea level rise.

1] We must prepare for rising seas and work to limit the long-term pace and magnitude of sea level rise by dramatically reducing global warming emissions. Communities must weigh the costs and risks of accommodating the rising seas, retreating from them, or trying to defend coastal properties and infrastructure with protective measures.

2] Traditional Defensive approaches -such as building seawalls and levees, or replenishing sand along eroded beaches -can help protect against flooding and damage but may not provide adequate or sustainable long-term protection.

3] Maintaining or restoring natural buffers, such as barrier islands, tidal wetlands, and mangroves, can also help defend coastlines.

4] Measures like elevating and flood proofing structures can help accommodate temporary flooding and gradual inundation.

5] The most vulnerable coastal communities may increasingly need to consider the stark option of some form of retreat from the rising seas.

6] To limit the long-term risks of sea level rise and the costs of adapting to it, we must work toward deep reductions in the Global warming emissions that are the primary cause of rising sea levels.

This educational PowerPoint Presentation (editable) is prepared by GEM Team (courtesy: internet). For other similar GEM PowerPoint Presentations on various environmental issues see next slide. These PPTs may be downloaded from our website www.stfrancisxavierpanvel.in

The GEM PPTs can be creatively used for various groups like school/college students, NGOs, government officials, Church groups, SCC groups, housing society members and so on.

Zero Garbage Solar Energy Junk Food Twenty Tips To Save Nature Plastic – a boon or bane?

Green Passion Soft drink – A Health Hazard Waste to energy Rain Water Harvesting Eco-friendly Religions Happy Green Diwali Climate Change The future of Biodiversity Genetically Modified Foods Waste Water Treatment Give thanks, Give Life (Body, Organ, Tissue Donation) Organic Farming Waste to cooking gas Reduce, Reuse. Recycle Protect Mangroves Say NO to Bottled water Save Lakes and Ponds Forests are green lungs Coal Mining and Ecology Sin of Food Waste Climate change and Poverty Stop Water Pollution Carbon Footprints Parks and Open Spaces Rising Sea Levels

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