Category Environtal Studies

WHAT IS NOISE POLLUTION AND ITS EFFECTS?

Noise pollution can be defined as unwanted or excessive sound that can have adverse effects on human health, wildlife, and environment quality. Sound is measured in decibels (dB) and the normal hearing frequency rate of healthy individuals ranges from 0 to 120 dB. Sounds that reach 85 decibels or higher can damage a person’s ears. Some audio sources that exceed this threshold include power lawn mowers (90 dB), trains (90 to 115 dB), and loud rock concerts (110 to 120 dB). Noise pollution impacts millions of people on a daily basis. The most common health problems it is responsible for include noise-induced hearing loss and high blood pressure.

Human Diseases Caused by Noise Pollution

Whether we realize we are subjected to it or not, noise pollution can be hazardous to our health in various ways.

Hypertension is, in this case, a direct result of noise pollution caused elevated blood levels for a longer period of time.
Hearing loss can be directly caused by noise pollution, whether listening to loud music in your headphones or being exposed to loud drilling noises at work, heavy air or land traffic, or separate incidents in which noise levels reach dangerous intervals, such as around140 dB for adult or 120 dB for children.
Sleep disturbances are usually caused by constant air or land traffic at night, and they are a serious condition in that they can affect everyday performance and lead to serious diseases.
Child development. Children appear to be more sensitive to noise pollution, and a number of noise-pollution-related diseases and dysfunctions are known to affect children, from hearing impairment to psychological and physical effects. Also, children who regularly use music players at high volumes are at risk of developing hearing dysfunctions. In 2001, it was estimated that 12.5% of American children between the ages of 6 to 19 years had impaired hearing in one or both ears
Various cardiovascular dysfunctions. Elevated blood pressure caused by noise pollution, especially during the night, can lead to various cardiovascular diseases.
Dementia isn’t necessarily caused by noise pollution, but its onset can be favored or compounded by noise pollution.
Psychological dysfunctions and noise annoyance. Noise annoyance is, in fact, a recognized name for an emotional reaction that can have an immediate impact.

Effects of Noise Pollution on Wildlife and Marine Life

Our oceans are no longer quiet. Thousands of oil drills, sonars, seismic survey devices, coastal recreational watercraft and shipping vessels are now populating our waters, and that is a serious cause of noise pollution for marine life. Whales are among the most affected, as their hearing helps them orient themselves, feed and communicate. Noise pollution thus interferes with cetaceans’ (whales and dolphins) feeding habits, reproductive patterns and migration routes, and can even cause hemorrhage and death.
Other than marine life, land animals are also affected by noise pollution in the form of traffic, firecrackers etc., and birds are especially affected by the increased air traffic.

Tips for Avoiding Noise Pollution

Wear earplugs whenever exposed to elevated noise levels.
Maintain a level of around 35 dB in your bedroom at night, and around 40 dB in your house during the day.
If possible, choose your residential area as far removed from heavy traffic as you can.
Avoid prolonged use of earphones, especially at elevated sound levels.
If possible, avoid jobs with regular exposure to elevated sound levels.

Credit : Environmental pollution centre 

Picture Credit : Google 

WHAT IS NITROGEN CYCLE? WHAT ARE THE STAGES OF NITROGEN CYCLE?

Our atmosphere is made up of 78% nitrogen. This element is essential for all living beings but we cannot directly take the nitrogen from the environment. We must absorb it through our food. The nitrogen cycle follows the circulation of nitrogen from the atmosphere to the soil, to animals and back. Nitrogen in the atmosphere falls to the earth through snow and rain. Once in the soil, the nitrogen combines with the hydrogen on the roots of the plants to form ammonia. This process is called Nitrogen fixation. Additional bacteria further combine this ammonia with oxygen in a process called Nitrification. At this point, the nitrogen is in a form called nitrite, which is further converted into nitrate by the bacteria. Plants can absorb nitrogen in this state through a process called assimilation and the rest is utilised by the bacteria. The remainder is released back into the atmosphere through the process of denitrification.

Nitrogen Cycle Explained – Stages of Nitrogen Cycle

Process of the Nitrogen Cycle consists of the following steps – Nitrogen fixation, Nitrification, Assimilation, Ammonification and Denitrification. These processes take place in several stages and are explained below:

Nitrogen Fixation Process

It is the initial step of the nitrogen cycle. Here, Atmospheric nitrogen (N2) which is primarily available in an inert form, is converted into the usable form -ammonia (NH3).

During the process of Nitrogen fixation, the inert form of nitrogen gas is deposited into soils from the atmosphere and surface waters, mainly through precipitation.

The entire process of Nitrogen fixation is completed by symbiotic bacteria, which are known as Diazotrophs. Azotobacter and Rhizobium also have a major role in this process. These bacteria consist of a nitrogenase enzyme, which has the capability to combine gaseous nitrogen with hydrogen to form ammonia.

Nitrogen fixation can occur either by atmospheric fixation- which involves lightening, or industrial fixation by manufacturing ammonia under high temperature and pressure conditions. This can also be fixed through man-made processes, primarily industrial processes that create ammonia and nitrogen-rich fertilisers.

Assimilation

Primary producers – plants take in the nitrogen compounds from the soil with the help of their roots, which are available in the form of ammonia, nitrite ions, nitrate ions or ammonium ions and are used in the formation of the plant and animal proteins. This way, it enters the food web when the primary consumers eat the plants.

Ammonification

When plants or animals die, the nitrogen present in the organic matter is released back into the soil. The decomposers, namely bacteria or fungi present in the soil, convert the organic matter back into ammonium. This process of decomposition produces ammonia, which is further used for other biological processes.

Denitrification

Denitrification is the process in which the nitrogen compounds make their way back into the atmosphere by converting nitrate (NO3-)  into gaseous nitrogen (N). This process of the nitrogen cycle is the final stage and occurs in the absence of oxygen. Denitrification is carried out by the denitrifying bacterial species- Clostridium and Pseudomonas, which will process nitrate to gain oxygen and gives out free nitrogen gas as a byproduct.

Conclusion

Nitrogen is abundant in the atmosphere, but it is unusable to plants or animals unless it is converted into nitrogen compounds.

Nitrogen-fixing bacteria play a crucial role in fixing atmospheric nitrogen into nitrogen compounds that can be used by plants.

The plants absorb the usable nitrogen compounds from the soil through their roots. Then, these nitrogen compounds are used for the production of proteins and other compounds in the plant cell.

Animals assimilate nitrogen by consuming these plants or other animals that contain nitrogen. Humans consume proteins from these plants and animals. The nitrogen then assimilates into our body system.

During the final stages of the nitrogen cycle, bacteria and fungi help decompose organic matter, where the nitrogenous compounds get dissolved into the soil which is again used by the plants.

Some bacteria then convert these nitrogenous compounds in the soil and turn it into nitrogen gas. Eventually, it goes back to the atmosphere.

These sets of processes repeat continuously and thus maintain the percentage of nitrogen in the atmosphere.

Credit : BYJU’S 

Picture Credit : Google 

WHAT IS A MONSOON SEASON?

A monsoon is a seasonal wind pattern that lasts for several months and results in heavy rainfall during the summer and dry spells in the winter. It is responsible for the wet and dry seasons throughout much of the tropics. Typically Indian monsoon lasts from June-September, with large areas of western and central India receiving more than 90% of their total annual precipitation during the period. The word comes from the Arabic ‘mausin’ which means season and was first used in the English language during the British occupation of India.

What causes a monsoon?

A monsoon (from the Arabic mawsim, which means “season”) arises due to a difference in temperatures between a land mass and the adjacent ocean, according to the National Weather Service. The sun warms the land and ocean differently, according to Southwest Climate Change, causing the winds to play “tug of war” eventually switching directions bringing the cooler, moister air from over the ocean. The winds reverse again at the end of the monsoon season.

Wet versus dry

A wet monsoon typically occurs during the summer months (about April through September) bringing heavy rains, according to National Geographic. On average, approximately 75 percent of India’s annual rainfall and about 50 percent of the North American monsoon region (according to a 2004 NOAA study) comes during the summer monsoon season. The wet monsoon begins when winds bringing cooler, more humid air from above the oceans to the land, as described above.

A dry monsoon typically occurs between October and April. Instead of coming from the oceans, the winds tend to come from drier, warmer climates such as from Mongolia and northwestern China down into India, according to National Geographic. Dry monsoons tend to be less powerful than their summer counterparts. Edward Guinan, an astronomy and meteorology professor at Villanova University, states that the winter monsoon occurs when “the land cools off faster than the water and a high pressure develops over the land, blocking any ocean air from penetrating.” This leads to a dry period.

The winds and rains

The monsoon season varies in strength each year bringing periods of lighter rains and heavier rains as well as slower wind speeds and higher wind speeds. The Indian Institute of Tropical Meteorology has compiled data showing yearly rainfalls across India for the last 145 years.

According to the data, the intensity of a monsoon varies over an average of period of 30 – 40 years. In each period, the amount of rain received is higher than average resulting in many floods or lower than average resulting in droughts. The long-term data suggest that the monsoon trends may turn from being in a low rain period that began in approximately 1970 to a higher rain period. Current records for 2016 indicate that total rainfall between June 1 and September 30 is 97.3 percent of the seasonal normal.

The most rain during a monsoon season, according to Guinan, was in Cherrapunji, in the state of Meghalaya in India between 1860 and 1861 when the region received 26,470 millimeters (1,047 inches) of rain. The area with the highest average annual total (which was observed over a ten year period) is Mawsynram, also in Meghalaya, with an average of 11,872 millimeters (467.4 inches) of rain.

The average wind speeds in Meghalaya during peak summer monsoon season average 4 kilometers per second and typically vary between 1 and 7 kilometers per hour, according to Meteoblue. During the winter months, wind speeds typically vary between 2 and 8 kilometers per hour with an average of 4 – 5 kilometers per hour.

Credit : Live science 

Picture Credit : Google 

WHAT IS THE KYOTO PROTOCOL?

The Kyoto Protocol was the first significant international treaty that aimed to combat global warming. It was named after the city (in Japan) in which it was adopted in December 1997.

It urged participating countries to develop national programmes to reduce emission of greenhouse gases (like carbon dioxide and methane). It came into effect only in 2005 after delayed approval. Since 1997, 191 countries have backed the agreement. However, some developed countries including the US, Canada, and Russia have denied meeting the emission targets.

While the Kyoto Protocol expired in 2020, the Paris Agreement is now the active instrument to fight climate change.

The Kyoto Protocol is based on the principles and provisions of the Convention and follows its annex-based structure. It only binds developed countries, and places a heavier burden on them under the principle of “common but differentiated responsibility and respective capabilities”, because it recognizes that they are largely responsible for the current high levels of GHG emissions in the atmosphere.

In its Annex B, the Kyoto Protocol sets binding emission reduction targets for 37 industrialized countries and economies in transition and the European Union. Overall, these targets add up to an average 5 per cent emission reduction compared to 1990 levels over the five year period 2008–2012 (the first commitment period).

In Doha, Qatar, on 8 December 2012, the Doha Amendment to the Kyoto Protocol was adopted for a second commitment period, starting in 2013 and lasting until 2020.

As of 28 October 2020, 147 Parties deposited their instrument of acceptance, therefore the threshold of 144 instruments of acceptance for entry into force of the Doha Amendment was achieved.  The amendment entered into force on 31 December 2020.

The amendment includes:

New commitments for Annex I Parties to the Kyoto Protocol who agreed to take on commitments in a second commitment period from 1 January 2013 to 31 December 2020;
A revised list of GHG to be reported on by Parties in the second commitment period; and
Amendments to several articles of the Kyoto Protocol which specifically referenced issues pertaining to the first commitment period and which needed to be updated for the second commitment period.

Credit : United nations climate change 

Picture Credit : Google 

WHAT IS ICEBERG CALVING

Iceberg calving, also called glacier calving, is the breaking away or release of huge ice chunks from the termini of glaciers or the margins of ice shelves. Ice shelves can calve huge tabular icebergs over decades or longer like the Antarctic’s Larsen C Sometimes, small fast flowing glaciers continuously calve small chunks of ice into their fjords like the San Rafael glacier in Chile.

Causes of iceberg calving

It is useful to classify causes of calving into first, second, and third order processes. First order processes are responsible for the overall rate of calving at the glacier scale. The first order cause of calving is longitudinal stretching, which controls the formation of crevasses. When crevasses penetrate the full thickness of the ice, calving will occur. Longitudinal stretching is controlled by friction at the base and edges of the glacier, glacier geometry and water pressure at the bed. These factors, therefore, exert the primary control on calving rate.

Second and third order calving processes can be considered to be superimposed on the first order process above, and control the occurrence of individual calving events, rather than the overall rate. Melting at the waterline is an important second order calving process as it undercuts the subaerial ice, leading to collapse. Other second order processes include tidal and seismic events, buoyant forces and melt water wedging.

When calving occurs due to waterline melting, only the subaerial part of the glacier will calve, leaving a submerged ‘foot’. Thus, a third order process is defined, whereby upward buoyant forces cause this ice foot to break off and emerge at the surface. This process is extremely dangerous, as it has been known to occur, without warning, up to 300m from the glacier terminus.

Credit : Wikipedia 

Picture Credit : Google 

WHAT IS HEAT WAVE?

Heatwave is a period of abnormally high surface temperatures relative to what’s actually expected over a region at a particular time of the year. Countries have adopted their own standards to declare a heatwave. Heatwaves occur in summer when the high pressure across an area moves slowly, thereby persisting over it for a few days or even weeks. Heatwaves have been observed globally since the 1950s, and have been associated with climate change. It can lead to heat-related stress such as dehydration, exhaustion and heatstroke.

Dangerous Heat

For some, a heat wave might sound like an excuse to run around with a hose or into some sprinklers. In reality, though, heat waves are no laughing matter. They are serious weather phenomena that can be quite dangerous.

How Do Heat Waves Form?

Heat waves are generally the result of trapped air. During the 2012 heat wave, air was trapped above much of North America for a long period of time. As opposed to cycling around the globe, it simply stayed put and warmed like the air inside an oven.

The culprit? A high-pressure system from Mexico. Between June 20th and June 23rd, this system migrated north. It grew in size, and it parked itself over the Great Plains of the United States.

High-pressure systems force air downward. This force prevents air near the ground from rising. The sinking air acts like a cap. It traps warm ground air in place. Without rising air, there was no rain, and nothing to prevent the hot air from getting hotter.

But that wasn’t all. A weather pattern that normally pulls air toward the east was also weaker at the time. That meant that there was little that could be done to push this high-pressure cap out of the way.

Credit : Sci jinks

Picture Credit : Google