Effects of Climate Change on Freshwater

Lake By Mountain


Of the 70% of the world that is covered in water, only 2.5% of it is actually fresh water. And of this 2.5%, only 1% of it is easily accessible; while glaciers and snowfields contain the remaining 1%. We are stating these facts because fresh water for centuries has been the core fabric of humankind.

To get their fair share of water, humans in the past fought several wars and signed numerous treaties. Water is a need without which life cannot sustain on this planet.

Water resources are integral to the development of any country and society. To all living organisms, water is the most crucial resource.  From drinking, bathing, washing to fishing and farming, without fresh water human life would cease to exist.

However, the world that has heavily relied on freshwater and will carry on doing so is now running out of this resource. Freshwater resources are depleting at a rapid rate making this an issue of grave concern.

To understand this, educating ourselves about the water cycle and how this natural process has been the primary source of water resources for the world since its inception is vital.

The Water Cycle

The 1% of freshwater that is easily accessible is involved in the continuous process of circulation. The method of water moving around the Earth's atmosphere is called Water Cycle.

There are four stages of the water cycle; each step plays a pivotal role in transferring water from one place to another. The process starts with evaporation. Evaporation is the process of moving water from the surface of the earth to the atmosphere. Evaporation occurs when water molecules gain kinetic energy due to high temperatures.

Evaporation usually occurs through soil, snow, and lakes. Another way that water joins the atmosphere is via transpiration, and this happens when water evaporates through the pores of the plants' leaves.

Once water reaches the atmosphere from all of its sources, the air in the atmosphere carries it. The stored water is called water vapor. Water vapor is a source of humidity in the environment, and it supplies water to the surface in the form of dew, frost, fog, clouds, and precipitation.

The water vapors, although a source of water is not exactly liquid. It is the process of condensation that converts the vapor into a liquid state. Condensation is a direct result of the air receiving more water vapor then it can carry. Condensation mainly occurs due to the cooling and mixture of air masses of different temperatures. The process converts the water vapor into liquid. Precipitation is the liquid form of water vapor.

Precipitation or rain falls to the Earth’s surface. Rainfall concludes the water cycle. Once it rains, the whole process restarts with evaporation from lakes and plants. Do keep in mind that the cycle is a continuous process, and each stage is taking place concurrently.    

However, recently the water cycle has been subject to remarkable changes. The areas where rain was once common now witnesses long periods of little or no rainfall followed by heavy and deadly rain. The excess rain causes lakes and rivers to flood.

Floods have wreaked havoc in recent times leading to a loss of countless lives and the destruction of property.

Why is this happening? What is the cause of this remarkable change in patterns of rainfall? Yes, you guessed it right - Climate Change.

Although human advancement has been at a steady rate since the industrial revolution, the effects of climate change and global warming have only just dawned upon us.

Pollution, the effects of greenhouse gases and overpopulation have all affected the climate adversely. We as human beings have failed to draw ethical boundaries on the use of this essential resource. Each resource has a role to play in maintaining the ecology of the system; once a resource is depleted the ecology gets affected. Freshwater is no different.

How Is the Water Cycle Affected?

Average temperatures continue to rise mainly due to actions of us human beings. Deforestation, pollution and an ever increasing population are few of the reasons for increased temperature. On average, the temperature has risen in the recent past, by approximately 0.7 degrees Celsius. At this going rate, most experts believe it can increase another 3 to 5 degrees by 2100.

The rapid change in climate has affected the water cycle in many ways. The first and most significant difference is the melting of glaciers and snow. When glaciers melt, it causes an increase in the flow of water in lakes and rivers.

The increased flow of water has led to an increase in the ability of the atmosphere to hold water; this leads to an increase in rainfall when the air gets cooler. Although it does raise the supply of water and adds to freshwater resources available it also causes the rapid movement of water from the atmosphere to the oceans.

This increase in the movement of water from the water source to the oceans reduces our ability to store and use it. The increasing temperature also implies a decrease in the snow, and as rainfall replaces snowfall, the process of evaporation speeds up.

The melting glaciers also increase freshwater supply most of which rushes to the oceans or spillover in the form of floods. However, the increased temperature means the rate at which glaciers are melting also increases. This increase also means that the increased water supply may not be available in the long run.

Regions where there is already significantly less rainfall and areas which are prone to long dry spells have seen a considerable decrease in the amount of precipitation. This change is because of rising temperatures; regions such as these in the future will be prone to less rainfall with no or little rain. Rainfall rather than occurring throughout the season will happen in the form of thunderstorm affecting life in the area.

The intensification of the overall water cycle is the primary cause of extreme drought and rainfall in these areas.

In addition to the intensification, water resources are also depleting because of rapid acidification. Acidification in oceans, which is harmful to marine life but also causes our ecosystem to become acid sensitive, is due to Carbon dioxide dissolving into the water's surface.

The “Wet Get Wetter and Dry Get Drier” Phenomena

Researchers conducting studies on the topic using climate models have predicted that due to the presence of heat-trapping gases in the atmosphere, precipitation will change in two main ways.

Strengthening of existing precipitation patterns

With an increase in temperature, warmer air is expected to trap more water vapor. Scientists are expecting an exponential increase in the amount of rainfall as warm air carries more water vapor. Regions that are already subject to relatively high rainfall will witness a surge in rainfall.

The surge in rainfall in comparatively wetter parts of the planet is referred to as the phenomena of the wet-get-wetter. Dry regions, however, will experience prolonged dry spells making them drier.

This change in global weather conditions is a cause for grave concern and is a call for immediate action.

Change in Storm Track

The second shift will be in the form of a change in storm tracks. Storm tracks are narrow zones in seas and oceans where storms are driven by prevalent winds. 

As atmospheric circulation increases, storm tracks will move away from the equator towards the poles. Storm tracks are essential for transporting heat, momentum, and moisture, which is why they strongly affect the climate of the surface.

Dynamics regarding the movements of these storm tracks is still unclear. However, climate models that are supported by observational data suggest that storm tracks move toward the North and South Poles as the weather warms up.

Understanding the Climate Model

In any climate change study, it is vitally important to uncover the reasoning behind the change of climate. You see there are cases when climate change occurs due to natural factors. For example, El Nino is a part of routine climate change which occurs when sea surface temperatures rise above normal levels. This process makes the wet regions wetter and dry drier.

However, for anyone studying climate change and its effects on ecology, it is vital for them to have the ability to differentiate the signal amid the noise. 

It is essential to know whether the change in some natural factor is due to seasonal variations or is a direct effect of climate change.

To determine the causes researchers use the tried and tested mechanism of observing and then applying data. Climate models available are run initially without the influence of greenhouse gases. Running these models without the impact of greenhouse gases helps in determining whether natural factors contributed to a change or not. 

The results are then observed to find out the reasons for the change of climate. The models used to study climate change give us a sound interpretation of what ails the Earth. We all know the symptoms but to find a long term curb to the ailing problem a dedicated effort is required.

Solutions

We are in a state of emergency, regardless of how serious the world leaders consider the issue of water shortage to be we need to act now. Depleting oil and gas resources may severely impact one's life, but running out of fresh water resources will have a devastating effect on the balance of life on our planet.

Water demand is globally projected to increase by 55% from 2000 to 2050; this increase in demand will be a problem when there is a shortage of fresh water. To meet the demand, preserving water resources is crucially important. There needs to be an engineered redistribution of water; funds should be used by governments to build dams and reservoirs.

An efficient piping system should be in place to ensure waste-effective transportation of water. Desalination plants should be installed to recover freshwater from the ocean.
Investments in research will be essential for combating water scarcity. Freshwater scarcity will affect the survival of all living things. In addition to making necessary changes in one's lifestyle, becoming a freshwater advocate and lending your voice for the preservation of water resources is also critically important.