a.) The impact of climatic change and global warming on sea and ice volumes:
Climate change is a long-term change in the earth’s climate, especially a change due to an increase in the average atmospheric temperature. Climate change affects the mass balance of glaciers and ice sheets. When the temperature exceeds a certain temperature for a long enough period, and/or there is insufficient precipitation, glaciers and ice sheets will lose mass. Sea level has been rising, likely primarily as a result of human induced climate change. During the 20th century, sea level rose about 1520 centimeters (roughly 1.5 to 2.0 mm/year), with the rate at the end of the century greater than over the early part of the century.
b.) The impact of rising sea levels:
A sea level rise is an increase in global mean sea level as a result of an increase in the volume of water in the world’s oceans. Sea level continues to rise at a rate of about one-eighth of an inch per year. The two major causes of global sea level rise are thermal expansion caused by warming of the ocean (since water expands as it warms) and increased melting of land-based ice, such as glaciers and ice sheets. As seawater reaches farther inland, it can cause destructive erosion, wetland flooding, aquifer and agricultural soil contamination, and lost habitat for fish, birds, and plants. During the last ice age, massive ice sheets covered portions of both the Northern and Southern hemispheres. When these massive ice sheets melted, they released the water locked inside them, which was enough liquid water to make the seas rise by about 390 ft. Also, the global mean sea level has been rising since the end of the last ice age almost 18,000 years ago. Globally, sea levels rose four to ten inches in the last century. Over 600 million people live in coastal areas that are less than 10 meters above sea level, and two thirds of the world’s cities that have populations over five million are located in these at risk areas. Coastal communities are particularly vulnerable to the effects of climate change, which puts much of the population at risk –loss of homes, infrastructure, livelihoods, and even lives.
c.) The impact of agriculture and the supply of water for industrial and domestic use upon natural supplies of water
The use of water in mass quantities is now a major controversial issue among governments and farmers. Water scarcity and usage have a huge impact on the agricultural world. The mass production of crops does not focus upon the recycling and treatment of used freshwater, therefore runoff and pollution of the water table occurs (with materials like phosphate in fertilizers.) This affects the amount of freshwater we have.
Ex.) Ogallala Aquifer: This aquifer is located underneath the great plains, and supplies the water for approximately 1⁄5of the nation’s wheat, corn, cotton, and cattle that is grown locally. Due to this mass amount of usage for agriculture, the water within the aquifer is being used too fast to be deemed sustainable. More than 90% of the aquifers usage goes toward crop irrigation in the great plains. At the rate it is being depleted, scientists estimate the aquifer will take approximately 6,000 years to replenish itself properly.
Ex.) Australian Artesian Basin: one of the largest underground water reservoirs in the world. It underlies approximately 22% of Australia—occupying more than 1.7 million square kilometers beneath the arid and semi-arid parts of Queensland, New South Wales, South Australia and the Northern Territory. The basin is being drilled extensively due to urban sprawling. When these wells are drilled, most are left open, and the groundwater rises and evaporates away.
d.) The interaction between growth in population and water supply in countries with contrasting levels of economic development.
Population and economic growth are putting pressure on available fresh water resources worldwide. Uncertain water availability is a challenge that many countries face, which can impact economic growth. This ‘water challenge’, and its links to economic growth, has multiple dimensions, one of which is access to safe drinking water and basic sanitation services. This ‘water challenge’, and its links to economic growth, has multiple dimensions, one of which is access to safe drinking water and basic sanitation services. Improved access has a direct positive impact on people and communities leading to significant social, economic and environmental benefits. Therefore, low economically developed countries employing technologies such as piped water and sewage connections to have access to more sanitary water.