The Prayas ePathshala

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06 November 2024

DAILY CURRENT AFFAIRS ANALYSIS

1 – Cloud seeding: GS III – Science and Technology

Important information:

An experiment using cloud seeding in the city of Solapur produced an 18% relative improvement in rainfall, or 8.67mm more.
Because Solapur is located on the leeward side of the Western Ghats, it receives little precipitation.
Two hours after seeding the clouds, the relative enhancement of collected rainfall was seen.
867 million litres of water were made more available overall as a result of the cloud seeding trials.

Which experiment was it?

In the summer monsoon season of 2018 and 2019, a scientific study known as the Cloud Aerosol Interaction and Precipitation Enhancement Experiment (CAIPEEX phase-4) was carried out in Solapur City.

Goal:

Developing a cloud seeding methodology and examining the effectiveness of hygroscopic seeding in deep convective clouds were the main goals.

How was it executed?

Two aeroplanes were utilised in the experiment to seed the clouds and examine different cloud properties.
The study discovered that, in the right circumstances, cloud seeding works well to increase rainfall in a certain area.
A randomised seeding experiment was conducted to investigate how well cloud seeding produces precipitation.
Out of the 276 convective clouds that were selected, 150 were seeded and the remaining 122 were not.
More rain fell from the seeded clouds than from the unseeded ones.
The clouds were seeded using calcium chloride flare.
When activated, a cloud seeding flare discharges these particles.
In order to allow the seed particles to enter the clouds with the least amount of dispersion, the seeding was done near the base of the warm convective clouds during the stage of cloud growth.

Important conclusions from the research:

While cloud seeding can help deliver 18% more rainfall and partially solve water requirements, it cannot prevent droughts on its own.
Implementing catchment-scale cloud seeding initiatives may aid in the management of drought conditions.
The study offers complex procedures and technical advice for organising and carrying out cloud seeding in India.

The two-year investigation contributed to the creation of a high-resolution numerical model that can assist interested parties in determining:

target areas
clouds with seeding capabilities, and
an effective seeding plan to increase the amount of rainfall in a region.
The study’s key discovery was that, even with cloud seeding, not all cumulus clouds result in precipitation.
Rainfall occurs in 20–25% of cumulus clouds when cloud seeding is done properly.
The real increase in rainfall across a 100 sq. km region was only 18, despite the fact that automatic rain gauges indicated a 46% relative augmentation of rainfall.
The approximate cost per litre for cloud seeding water production was 18 paisa.
If we employ domestic seeding planes, the cost will decrease by over 50%.

Cloud seeding: What is it?

Little water vapour in the atmosphere cools and condenses around a tiny dust or salt particle floating in the atmosphere to produce tiny water droplets or ice crystals, which make up clouds.
Precipitation cannot happen and raindrops or snowflakes cannot form without these particles, sometimes referred to as condensation or ice nuclei.
By inserting small ice nuclei into specific kinds of subfreezing clouds, a weather modification technique known as “cloud seeding” increases a cloud’s capacity to generate rain or snow.
These nuclei give snowflakes a place to start.
Cloud seeding results in newly produced snowflakes that expand swiftly and fall back to the Earth’s surface, boosting streamflow and snowpack.

Source – The Hindu

2 – Developed nations will exceed the target for carbon emissions: GS II – International Issues

Important information:

The study is being conducted in advance of the UN Framework Convention on Climate Change’s 28th Conference of Parties (COP-28), which will take place in Dubai.
It indicates that the United States, Russia, and the European Union will be responsible for 83% of this overshoot.
Countries are due to report on their Nationally Determined Contributions (NDCs), or UN-mandated emission reduction commitments, at COP-28.
Countries outline the steps they will take to cut their greenhouse gas emissions in their NDCs in order to meet the objectives of the Paris Agreement.
The steps that each nation will take to increase resilience and prepare for the effects of climate change are also included in their NDCs.
According to the study, the industrialised countries’ NDCs do not yet meet the worldwide average emission reduction of 43% below 2019 levels, which is required to prevent global temperatures from rising above 1.5 degrees Celsius.
Rather, the combined NDCs of industrialised nations only represent a 36% reduction.

Actions taken to stop global warming:

Rich nations are required to spearhead international efforts to cut greenhouse gas emissions with legally binding objectives after decades of negotiations.
The developed world was supposed to cut emissions overall between 2008 and 2012 by 5% from 1990 levels and between 2013 and 2020 by 18%.
By 2050, a number of nations have pledged to achieve net zero carbon emissions.
This would necessitate consistent, quantifiable reductions every ten years until that year.

Present situation:

As a stepping stone, nations provided the UN with information about their anticipated reductions through 2030.
Developed nations must reduce emissions to 43% below 2019 levels in order to keep temperatures below 1.5 degrees Celsius.
But according to the analysis, given their present emissions trajectories, their reductions by 2030 would probably only total 11%.
With the exception of Belarus and Norway, not a single developed nation appears to be headed towards achieving its 2030 targets.
Despite this, Kazakhstan and Japan are predicted to miss their goals by a mere percentage point.

Source – The Hindu

3 – The growth of communities in places vulnerable to flooding: GS I – Urbanization related issues

Important information:

The study claims that since 1985, the number of people living in flood-prone areas has more than doubled.
The results highlight India’s vulnerability to unsustainable urbanisation.
The study also discovered that compared to low- and high-income countries, middle-income nations like India have a higher number of urban settlements in flood-prone areas.

Why is India vulnerable?

India was the third-largest contributor to global settlements, behind China and the United States, although it is not one of the 20 nations whose settlements are most vulnerable to flooding.
It ranks third among nations from 1985 to 2015 with new settlements growing into flood-prone zones, after China and Vietnam.
This indicates that, if the nation isn’t vigilant, India is seriously at risk of experiencing flood-related issues that could get worse in the upcoming years.

Bengaluru, for instance:

The city of Bengaluru lost ₹225 crore due to the floods.
The population of the city increased from approximately 1.6 lakh to over a crore between 1901 and 2022.
The city grew to accommodate these people, but new neighbourhoods ignored the terrain of the area.

Who is impacted the most?

The hazards are disproportionately greater for people who reside in non-formal arrangements.
The geography of low-income informal dwelling is closely linked to the geography of environmental danger.
In cities, informal housing is typically located in low-lying, flood-prone locations on undeveloped, unappealing property, where it allows residents to remain without being forcibly removed.

Why cities grow in high-risk zones for flooding?

Absence of leadership:

Due in large part to the lack of regulatory mechanisms, urbanisation has spread into flood-prone areas despite the fact that this type of growth is not environmentally viable.
When it comes to new construction, environmental rules are frequently only applied to large infrastructure projects rather than medium- and small-scale locality alterations.
This runs counter to the idea that floods and flood risk are localised problems and that some areas are more prone to flooding than others.

Breaking the law:

People frequently break the laws that are in place.

As an illustration:

an increase in forest-based ecotourism resorts.
the building of substantial structures, such as government buildings.
religious buildings on the floodplains of rivers.

Path ahead:

We can no longer prevent cities from growing into places that are vulnerable to flooding as they continue to grow.
Expansion into flood-prone areas is typically driven by market pressures.
However, the first step towards risk-aware, sustainable urban design is knowing what these places are and that we are expanding into them.
Certain adaptations are required, and they must distinguish between low-income inhabitants and unauthorised buildings built for the wealthy.
Every city must map the regions that are vulnerable to flooding using scientific methods.
Urban governments must safeguard low-income housing and increase the resilience of homes in these locations to flooding.
A few instances that can be modified are riverbank communities with stilt buildings, such as the Mishing and Miyah tribes near the Brahmaputra.

Source – The Hindu

4 – Xerography: GS III – Science and Technology

About photocopying:

In general, photocopying is a group of methods for making copies of content utilising light as one of the mediums.
But the term “photocopying” as it is used colloquially today almost entirely relates to xerography.
The Greek root word “xero,” which means “dry,” is the source of both the word “xerography” and the company name “Xerox.”
This is so that photocopying processes involving dirty liquid chemicals are avoided, such as xerography.

Fundamental xerographic components:

A surface that conducts light:

The first is a surface that has been covered in a photoconductive substance, or a photoconductive surface.
When such a substance is exposed to light, it conducts electricity by allowing electrons to pass through it, but in the dark, it inhibits them.
A thin, highly voltaged, negatively charged wire is placed adjacent to this surface to create a negative charge.
The sheet of paper that needs to be duplicated is then brightly lit.
While the unmarked portions of the paper reflect light, the darker portions do not.
Lenses and mirrors transfer this reflected light, causing it to land on the photoconductive surface.
The photoconducting material will turn conductive in the areas of its surface where light falls, allowing the electrons close to its surface to disperse downward (into a grounding).
As a result, the portions of the paper-to-be-copied (TBC) where anything was printed will match the portions that are still negatively charged after this step.

Toner application:

Toner is a powder that is applied to the surface.
Since the toner has a positive charge, it will settle in areas where the surface still has a negative charge.
After that, the surface transfers the toner’s pattern to a piece of paper.
The toner jumps because the paper has a larger negative charge.

The ultimate outcome:

Heat is applied to the toner causing it to melt and fuse with the paper.
This is the paper that emerges from the photocopier after a brief but efficient processing time.
In actual application, a revolving drum is utilised in place of a flat surface, and a moving scanner or a flashing or stroboscopic light illuminates the paper TBC.

Who made xerography possible?

By 1938, an American lawyer by the name of Chester F. Carlson had developed a basic kind of xerography.
After seven years, he sold the invention to the Ohio-based nonprofit Battelle Memorial Institute, where scientists improved the method.
1946 saw the Haloid Photographic Company buy a licence from Battelle to construct a machine utilising the method, one year later.
In 1948, the company registered the name “Xerox machine” as a trademark, and the first model went on sale in 1949.
The term “xerography” was created by Haloid’s managers, who did away with Carlson’s “electrophotography.”

Source – The Hindu