How Are They Formed?
Glaciers are formed when the snow that has fallen remains long enough to get compressed by fresh snow, and turns into solid ice. Almost throughout the year, new layers of snow will fall and compress the layers below.
For a glacier to form, it is very important that the amount of snow that falls in a given year is more than the amount of glacier ice/fresh snow that melts. It is only in this way that any glacier can increase in size. If the amount of fresh snow is less than the amount of melting ice/snow, then the glacier will diminish in size and gradually vanish. This is exactly what is happening with almost all glaciers on our planet. The ones that have taken centuries to form are melting at an alarming rate. Some well-known ones have diminished in size, and some have become extinct; all in the time period of the past 100 years.
Do They Melt Normally?
This is a normal process, and all glaciers melt to some extent during warmer climates. Certain glaciers melt constantly, but are replenished with the falling of more snow. Many communities depend on these melting glaciers for their freshwater needs. Water for drinking and farming is supplied by these rivers of ice, without which these communities would have to move and settle down where other sources of freshwater are available. Some nations depend on this constant flow of water to produce hydroelectricity, which costs less to produce and is extremely ecofriendly.
This process is perfectly normal, as long as the amount of ice that is melting is replaced by the same or more amount of fresh snow. A serious problem occurs when things go the other way - the ice melts too fast, and the fresh falling snow is not able to replace it. When this happens, the glacier will gradually begin diminishing in size, and will vanish completely.
What If They Melt Totally?
Many glaciers across the world are diminishing in size each year. Some well-known ones of the past have just melted away, never to return. The speed at which this process is taking place is getting increasing with each passing year. Almost everyone today agrees to one major cause for this - 'Global Warming'.
Many persons/communities that depend totally on glacier water for drinking and irrigation purposes have already felt the horrible effects of fast melting. These glaciers are bad not just for us humans, but also for animals, birds, fish, and marine plants.
Lakes Formed out of Glacier Water Could Burst
Glaciers that are melting faster than normal create lakes on the mountainsides as they flow. The size of these water bodies keeps on increasing with time. The walls that hold these lakes can bear pressures only up to certain limits. Once the water in these lakes increase to levels, where the limits are crossed, the lake will burst. As they are huge in size, the sudden amount of water released by the bursting will be tremendous. The force will destroy anything that comes in its way; including entire villages settled on the bottom of such mountains. Such disasters are a current reality, and have already happened (for example, in Nepal and Bhutan) causing tremendous loss to the villagers who were affected by it. Many places in these countries still face grave dangers from such lakes that are increasing in size, and could burst anytime.
When the amount of ice/snow melting on mountains increases above normal, it will cause a lot of water to be released into streams, and finally the rivers it feeds. This will cause flooding all along the river banks. All those living in low lying areas in close proximity of the rivers will be affected. The amount of havoc that floods can create is very well-known worldwide. People affected will have to relocate to safer regions.
Floods bring with them tremendous misery. Waterborne disease will be widespread and very difficult to curtail. Pure drinking water will not be available. Irrigated farmlands will drown, and crops will be destroyed. Living in such areas will not be humanly possible.
Once these glaciers have completely melted, the streams and rivers that are fed by them will run dry. People depending on these sources for all their freshwater needs will not have any source of water (unless fresh groundwater is available). Entire villages will have to resettle elsewhere. Places that are abundant in the production of crops for their needs, and also the needs of others will face famine. Food grains will be in short supply.
Sea Levels Will Rise
We are already witness to a sea level rise in the past century. This is minor proportions, but if the sea continues to rise further, it could have devastating effects. Persons living in low-lying areas on the seashore will be the first to be affected. Entire areas around the seashore will be flooded, making it compulsory for people in close vicinity to relocate. All fresh groundwater in the surrounding areas will get contaminated with sea water, which will be unfit for human consumption and for agriculture.
Global Temperatures Will Rise Further
Glaciers absorb approximately 20% heat from the sun, reflecting the remaining 80% back into space. When these glaciers melt and expose the Earth below, exactly the opposite will take place. Earth will absorb 80% of heat and reflect just 20% into space. This in turn will cause global temperatures to rise further, leading to a faster melting of the remaining glaciers.
Animals, Birds, and Fish Will Be Affected
Many species of animals, birds, and fish that depend on the glacier waters that empty into the sea will be affected. Many fish in such areas depend for their food on the coral reefs that are in abundance. When sea levels rise, the sunlight that these corals receive will diminish, and they may deteriorate or even vanish. This will affect the fish that feed on it. Birds and animals that depend on these fish for survival will be affected due to a shortage of fish. Humans in such areas depending on these animals, birds, and fish for food will be affected.
Who is Responsible For Vanishing Glaciers?
Almost everyone today believe that the prime cause of fast vanishing glaciers is global warming. The industrial revolution of the past century started it all, and it has just got worse with every passing year. Greenhouse gas emissions are at an all time high. We all contribute in some way or the other to global warming.
We may not be able to reverse the situation, but by living in a responsible manner, we may be able to drastically slow down the process of global warming. This may not help us much today, but it will surely have a positive effect on the future generations.