Sea Level Change and Ozone Depletion

Summary

The lecture addresses critical global environmental issues: sea level change and ozone layer depletion. It explains sea level change as the fluctuation of Earth's oceanic water levels influenced by factors like polar ice melting, glaciers, and thermal expansion due to global warming. The talk highlights the accelerated rate of sea level rise since the Industrial Revolution and its socio-economic impacts, including coastal erosion and displacement of communities. It also discusses ozone depletion, primarily caused by human activities releasing chemicals like CFCs and halons, leading to increased UV radiation, which poses threats to human health and ecosystems.

Takeaways

• 🌊 Sea level change refers to the variation in the Earth's oceanic water levels over time, influenced by factors such as polar ice caps, glaciers, and thermal expansion due to global warming.
• 📈 Global average sea level has risen significantly since 1880, with a record high set in 2022, and the rate of increase is accelerating, posing threats to coastal communities and infrastructure.
• 🌡️ Climate change is a primary driver of sea level change, with rising global temperatures leading to the melting of ice caps and glaciers, contributing to sea level rise.
• 🌊 Human activities, such as deforestation and construction of dams, indirectly impact glaciation and sea level change by contributing to global warming.
• 🏞️ Coastal erosion, increased flooding, and loss of coastal habitats are some of the direct consequences of rising sea levels, affecting biodiversity and human settlements.
• 💧 The melting of Arctic sea ice is emphasized as a significant cause of sea level rise, with floating ice contributing to the increase and impacting ocean circulation patterns.
• 🌐 Ozone layer depletion, caused by the release of chemicals containing chlorine or bromine, is another critical environmental issue linked to increased UV radiation and climate change.
• ❄️ The Montreal Protocol, an international agreement aimed at halting the production and use of ozone-depleting chemicals, has been instrumental in addressing this issue.
• 🌞 Increased UV radiation due to ozone depletion has direct and indirect health impacts, including skin cancer, cataracts, and respiratory conditions.
• 🛠️ Human-made chemicals such as CFCs, Halons, carbon tetrachloride, and methyl chloroform are identified as leading factors in ozone layer depletion.
• 🌳 The ozone layer acts as Earth's natural sunscreen, and its depletion leads to ecosystem disruptions and increased UV radiation, affecting both human health and the environment.

Q & A

What is the main topic of the lecture?

The main topic of the lecture is sea level change and ozone layer depletion, which are important global environmental issues.

What does sea level change refer to?

Sea level change refers to the variation in the average level of the Earth's oceanic water over time, influenced by factors such as polar ice caps, glaciers, and thermal expansion of seawater due to global warming.

What are the consequences of sea level change for coastal communities?

The consequences of sea level change for coastal communities include erosion, flooding, displacement of communities, and inundation, which can impact social life activities and local economies.

How much has the global average sea level risen since 1880?

The global average sea level has risen 8 to 9 inches (21 to 24 cm) since 1880.

What is the rate of global sea level rise from 2006 to 2015?

The rate of global sea level rise from 2006 to 2015 is 0.14 inches per year, which is more than double the rate of 0.06 inches per year throughout most of the 20th century.

What is the Montreal Protocol and its significance?

The Montreal Protocol is an international agreement ratified in 1987 aimed at halting the production and use of ozone-depleting chemicals, which is significant in addressing ozone layer depletion.

What are the main human activities contributing to sea level change?

Human activities contributing to sea level change include industrial activities leading to global warming, deforestation, groundwater extraction, and construction of dams and reservoirs.

How does the melting of polar ice caps and glaciers contribute to sea level rise?

The melting of polar ice caps and glaciers contributes to sea level rise by adding a significant amount of fresh water to the oceans, increasing the overall volume of water.

What is the impact of ozone layer depletion on human health?

Ozone layer depletion leads to increased UV radiation, which can cause skin cancer, cataracts, and other health issues such as respiratory conditions and premature aging of the skin.

What are some of the chemicals responsible for ozone layer depletion?

Chemicals responsible for ozone layer depletion include chlorofluorocarbons (CFCs), halons, carbon tetrachloride, and nitrous oxide (N2O), which release chlorine or bromine atoms that destroy ozone molecules.

What is the role of the ozone layer in the Earth's environment?

The ozone layer acts as Earth's natural sunscreen, protecting life on Earth from harmful ultraviolet radiation. Depletion of this layer allows more UV radiation to reach the Earth's surface, leading to various environmental and health issues.

Outlines

00:00

🌊 Sea Level Change and Its Impacts

The speaker expresses gratitude for the opportunity to discuss the critical global issue of sea level change. Sea level change is defined as the variation in Earth's oceanic water levels over time, influenced by factors such as polar ice caps, glaciers, and thermal expansion due to global warming. The speaker highlights the social and environmental impacts, including erosion, flooding, and displacement of communities. Notably, the global average sea level has risen significantly since the Industrial Revolution, with an accelerating rate of increase. Data from www.climate.gov illustrates the progressive change in sea levels, indicating a potential for future challenges.

05:03

🌍 Causes of Sea Level Change and Climate Change

This paragraph delves into the primary drivers of sea level change, emphasizing climate change and its effects on ice caps and glaciers. Human activities, such as deforestation and construction, indirectly impact glaciation, increasing the risk of melting. The speaker also discusses glacial isostatic adjustment and changes in ocean circulation, which can redistribute water and affect sea levels regionally. The melting of Arctic sea ice is particularly concerning, as it contributes to sea level rise and alters the albedo effect, further exacerbating global warming. The impacts of sea level rise, such as coastal erosion, flooding, and ecosystem loss, are significant and threaten both local communities and biodiversity.

10:05

🏞️ Socioeconomic and Environmental Ramifications of Sea Level Rise

The speaker outlines the socioeconomic and environmental challenges posed by sea level rise, including the displacement of communities and the potential loss of freshwater resources. The intrusion of saltwater into coastal aquifers and freshwater systems threatens drinking water supplies, while ecosystem loss can disrupt aquatic life and coastal habitats. The economic impact of sea level rise is also significant, affecting industries such as tourism, fisheries, agriculture, and real estate, and leading to increased insurance costs and infrastructure damage. The speaker also addresses the challenges of relocating and rehabilitating displaced populations.

15:09

🌞 Ozone Layer Depletion and Its Consequences

The final paragraph shifts focus to the issue of ozone layer depletion, caused by the release of chemical compounds containing chlorine or bromine from human activities. The thinning of the ozone layer is most pronounced over the polar regions, particularly Antarctica. The speaker connects ozone depletion to increased ultraviolet radiation, which poses health risks such as skin cancer and cataracts, and can also disrupt ecosystems. The Montreal Protocol is mentioned as an international effort to halt the production of ozone-depleting substances. The speaker concludes by discussing the role of the ozone layer as Earth's natural sunscreen and the importance of protecting it to mitigate the harmful effects of increased UV radiation.

Keywords

💡Sea Level Change

Sea level change refers to the variation in the average level of the Earth's oceanic water over time. It is a central theme of the video, illustrating the impact of global warming and melting ice caps on the Earth's environment. The script discusses how sea level rise can lead to erosion, flooding, and displacement of communities, with the global average sea level having risen significantly since 1880.

💡Ozone Layer Depletion

Ozone layer depletion is the gradual thinning of the ozone layer in the upper atmosphere due to the release of certain chemical compounds. The script explains its relevance to global environmental issues, particularly how it increases UV radiation, affecting both human health and the ecosystem. The video mentions the ozone hole over Antarctica as a significant example.

💡Global Warming

Global warming is the long-term increase in Earth's average surface temperature due to human activities, such as the emission of greenhouse gases. In the script, it is identified as a primary driver of sea level change through the melting of polar ice caps and glaciers, contributing to the rise in sea levels.

💡Polar Ice Caps

Polar ice caps are large masses of ice found at the Earth's poles. The script discusses how the melting of these ice caps, particularly in Antarctica and Greenland, contributes significantly to sea level rise, which is a direct consequence of global warming.

💡Thermal Expansion

Thermal expansion is the process by which matter expands when heated. In the context of the video, thermal expansion of seawater due to global warming is highlighted as an important factor influencing sea level change, as warmer water occupies more volume.

💡Coastal Erosion

Coastal erosion is the wearing away of the coastline due to the action of the sea. The script explains how rising sea levels contribute to increased erosion, impacting coastal habitats and communities, and leading to the loss of important ecosystems and biodiversity.

💡Climate Change

Climate change refers to long-term shifts in temperatures and weather patterns. The video script emphasizes climate change as a root cause of sea level change and ozone layer depletion, illustrating the interconnectedness of these global issues.

💡Glacial Isostatic Adjustment

Glacial isostatic adjustment is the slow uplift or rebound of the Earth's crust following the melting of massive ice sheets. The script mentions this geological process as a factor in sea level change, particularly in regions that were once covered by ice during the last ice age.

💡Ocean Currents

Ocean currents are the continuous movement of ocean water in a specific direction, driven by various factors including temperature and salinity. The script discusses how changes in ocean circulation patterns can redistribute water and influence sea levels regionally.

💡Montreal Protocol

The Montreal Protocol is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. The script refers to this protocol as a significant measure taken to halt the production and use of ozone-depleting chemicals.

💡UV Radiation

UV radiation, or ultraviolet radiation, is a form of electromagnetic radiation with shorter wavelengths than visible light. The script explains the harmful effects of increased UV radiation due to ozone layer depletion, such as skin cancer and cataracts, and its role in accelerating the melting of ice and snow.

Highlights

Sea level change and ozone layer depletion are important global issues impacting the environment and future planning.

Sea level change refers to variations in Earth's oceanic water levels over time, influenced by factors like polar ice caps, glaciers, and thermal expansion.

Global average sea level has risen 8-9 cm since 1880, with most of the increase occurring after the Industrial Revolution.

The rate of global sea level rise is accelerating, more than doubling from 0.06 mm/year in the 20th century to 0.14 mm/year from 2006-2015.

Melting of polar ice caps and glaciers contributes significantly to sea level rise due to human activities like deforestation and construction of dams.

Glacial isostatic adjustment in regions like North America and Scandinavia impacts sea levels as the land rebounds from ice removal.

Changes in ocean circulation patterns, like the Gulf Stream, can redistribute water and affect regional sea levels.

Melting Arctic sea ice contributes to sea level rise and increased absorption of sunlight by darker ocean water, further contributing to warming.

Rising sea levels lead to coastal erosion, increased flooding, and loss of coastal habitats, impacting biodiversity and ecosystems.

Saltwater intrusion from sea level rise can contaminate coastal aquifers and freshwater systems, affecting drinking water supplies.

Ozone layer depletion, caused by chemicals like CFCs and halons, allows more UV radiation to reach the Earth's surface, increasing health risks.

The Montreal Protocol, ratified in 1987, aimed to halt the production and use of ozone-depleting chemicals.

Ozone depletion leads to increased UV radiation, which can degrade materials like plastics, rubber, and fabric.

Health impacts of ozone depletion include increased risks of skin cancer, cataracts, respiratory conditions, and immune system issues.

Ecosystem disruptions from increased UV radiation can harm aquatic life and affect the balance of marine ecosystems.

Sea level rise and ozone depletion have significant socioeconomic and political impacts, affecting communities and requiring adaptation strategies.

Economic impacts of sea level rise include effects on industries like tourism, fisheries, agriculture, and real estate, as well as infrastructure damage and increased insurance costs.

Transcripts

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good afternoon

everyone first of all I want to be

thankful to the university

Authority and the respected Madam

iqc for offering this chance to talk on

the topic today the topic I going to

discuss is a course of of SEC course 2

and the title of the lecture is sea

level change and ozone layer depletion

one of the very important Global issues

that are becoming

nowadays

highly important for a futuristic plan

and to save our

environment what is sea level change the

first question comes to our mind a sea

level change refers to the variation in

the average level of the Earth's Oceanic

water over time and the change can be

influenced by various factors especially

the polar ice caps the glaciers and

important issue is thermal expansion of

the sea water due to global warming so

in one hand due to the oceanic currents

tectonic movements the sea level is

always

receiving uh an

oscillating character and over supply of

Water by melting ice caps can make the

level of water to be increasing

vertically and this will definitely lead

to

erosion flood displacement of

communities from their native places and

localities so these are the important

social life uh activities that will be

highly impacted by the sea level change

and the chances of inundation and

transgression is a very vital important

issues not only for the uh local

communities of rural areas but also for

the Metro cities it is very important to

be considered global average sea level

has risen 8 to 9 in 21 to 24 cm since

1880 mostly connecting after the

Industrial

Revolution in 2022 global average sea

level set a new record high

101.2 mm above 1993 levels and the rate

of global sea level is highly

accelerating more than double from uh

0.06 in per year throughout the most of

the 20th century to 0.14 in per year

from 2006 to

2015 out of this important uh databases

one thing is very important to note that

the rate of increment is always

happening to be developing the level of

the C from its earlier position to the

successive periods

this is a database gathered from the

www. climate.gov

where we are seeing how changing in the

sea level compared to 1993 2008 average

and uh this is really changing the scale

is in millimeter and the x-axis it is

showing the year marks and after 1880

the scenario in 2020 how it has reached

to a

very

high

Progressive change a positive change a

high positive change in the sea level

growth and that has really uh discovered

the chances to see that in future what

is going to

happen this is the sea level change 1993

to that of 2022 the global sea level

change scenario taken from the same

source and where we are seeing the

change in sea level in the world uh over

the world and for the important

countries at a

glance considering this fact first we

should reach to find out the causes this

is the most important it's like the root

of a plant and the main is the cause

climate change one of the prim Prim Ary

drivers of sea level change is climate

change the increase in global

temperature leads to the melting of ice

caps already say glaciers contributing

fresh water to the ocean now melting of

ice caps and Glaciers the melting of

polar ice caps such as those in the

Antarctica and Greenland and Glaciers

around the world contribute significant

amount of water reaching to the

oceans in view of this human influence

and human activities such as groundwater

extraction deforestation construction of

dams

reservers have indirectly impacted upon

the cases of

glaciation over the time due to global

warming and deforestation the chances of

melting has going to be very very high

even the forest line in the upper parts

of the mountainous belts the forest line

the Snow Line This is also changing at a

very faster rate and it is assuming by

the scientist that after

2050 many of the Metro cities not only

in the world this maybe in our country

are chanceful to be

deluged glacial isostatic adjustment

should also be considered here under

discussion in regions that were once

covered by Massive ice seeds during the

last ice age such as parts of North

America Scandinavian countries uh I will

refer the names of uh Netherland then

Finland some of the Scandinavian

countries uh Norway okay the land is

still slowly rebounding as the weight of

the ice is removed similarly changes in

Ocean circulation is also impacting

regularly alteration in Ocean

circulation patterns can affect sea

level Regional

changes in the currents such as the Gulf

Stream can redistribute water and

influence sea level in different parts

of the world and the ocean current and

their circulations are really very

important in this regard melting of the

Arctic sea ice is one of the very

important causes given more emphasis by

the scientists not only in view of

melting of the ice but also the floating

of the sea ice the floating of the sea

ice directly contribute to sea level

rise in the preceding time maybe the

icebergs and the floating ices are

frozen nowadays but over the time

temperature changes will cause into

delation of that and directly loss of

refle reflective sea ice leads to

increased absorption of sunlight by the

darker ocean water and further

contributing to

warming impacts of sea level change

Coastal erosion rising sea level

contribute to increased erosion of the

coastlines increased flooding higher sea

levels raise the Baseline for storm

surges and uh High tipes increasing the

frequency and uh severity of the coastal

flooding events low-lying coastal areas

become more prone to inundations

loss of coastal habitat is a really big

loss because the species is

dangered uh endangered

species uh the threatened species rare

species and some of the very important

species as contributing their important

role for The Aquatic ecosystems can also

be hampered wetlands and Man groups have

the very direct impact salt mares may be

some merged under the clutches of the

Salty Sea water and that may be

permanently unproductive even if they

are Exum after withdrawal of the uh

flood water but everything is becoming

to be a very chanceful the supply of the

melting water versus its withdrawal is

completely situational over time and the

S line stabilization habited for

biodiversity and the biodiversity

protection Against The Storm surges the

loss of life and the reduced level of

resilience of the coastal people or the

coastal communities to fight against the

uh sea level rises and submergences by

sea water salty water can be a very uh

high level of challenges in

future salt water

intrusion I have already said that the

salt water if they start in intruding

into the coastal aquifers and freshwater

systems it will completely destroy even

the chances of drinking water uh

harnessing the uh amount of drinking

water will be also lossing if the ice

works are all coming to be molten the

good uh Sweet Water will also be

unavailable in future and ecosystem loss

this is additional very badly effects

will come displacement of communities

already you can understand that if the

life is in challenge under submargin so

living being lowline coastal areas the

living being in the lowline coastal

areas especially in the developing

countries rising sea level can force

people to relocate to new locations and

the chances of Rehabilitation government

will also be in challenge to relocate

this uh uh uh destitute people this uh

uh victimize people and how to uh give

them with the new livelihoods can also

find out some newer uh challenges in the

social life so it will not only hamper

the physical setup of any geographical

area it will also impact upon the

socioeconomic and political challenges

impact on economy and livelihoods the

sea level rise can have significant

economic impact on coastal regions

affecting Industries such as tourism

Fisheries Agriculture and real estate

and damage to infrastructure loss of

property and increased insurance cost

that will be a very important one so

ozone hole depletion ozone hole

depletion uh is another important issue

and uh gradual thinning of 's ozone

layer in the upper atmosphere caused by

the release of chemical compounds

containing gaseous chlorine or bromine

from industry and other human

activities the thinning is most

pronounced in the polar regions

especially over Antarctica and ozone

depletion is a very important major

environmental problem why I have clapped

these two topics together because in one

hand ozone layer depletion is becoming a

very important cause of the Ozone gas to

penetrate inside the Aquatic lives and

that also impacting the delation I mean

the melting of the snow if the

ultraviolet radiation that reaches Earth

surface which increases the rate of skin

cancer eye cataracts genetic problems

immune system these are the other issues

but it will definitely uh increase the

chances of melting the Montreal protocol

we know that it ratified in the year of

1987 was the first of several

comprehensive International agreements

ended to Halt the production

and use of ozone depletion

chemicals so this is the scenario lowest

value of ozone measured by uh Toms each

year in the ozone hole the source is

given here and this is the ozone hole in

the North America strong long waves and

weak long long waves we are seeing the

two contrasting features in the year of

1984 uh we are seeing that uh uh in the

northern part concerning the

Alaska Greenland and the Very frigid

areas of uh Northern pole we are seeing

uh the situation and in

1997 definitely we are also seeing the

situation from how uh the strong long

waves uh the North America during 84

abnormally warm reducing ozone depletion

and 97

abnormally cold resulting in increased

seasonal

depletion this is the ozone

cycle oxygen molecules are photoed

yelding two oxygen atoms ozone and

oxygen atom are continuously

being interconverted as solar UV and

ozone is lost by a reaction of the

oxygen atom and this

uh inter uh uh connections of the uh

releasing of O3 and the important global

warming are highly uh important uh we

see that if oxygen uh where it is uh

considered to be a very resourceful gas

on the other hand uh O3 is considered to

be one of the very important greenhouse

gases that causing the depletion of

ozone

layer so causes of ozone layer depletion

I will go a bit F chlorofluorocarbon

CFCs and mostly uh aerosol propolin we

know that refrigerators and the

production of these release the

chlorofluorocarbon in the atmosphere and

this chlorine atoms can uh catalytically

destroy the ozone molecules so

destruction of ozone molecules is a very

fatal Factor Hons Hons are similar to

CFCs but contain bromine atoms insteed

of chlorine and they are commonly used

in the fire extinguisher and fire

fighting equipments like CFCs allons can

release bromine atoms in the

stratosphere contributing to Ozone

depletion and releasing of uh uh uh

bromine atoms due to Hons uh

contributing to the uh puncturing the

stratosphere is really very much fatle

for the future civilization carbon uh

tetrachloride is another chemical

compound that can release chlorine atoms

when it is broken down in the

stratosphere it was previously used as a

solvent as a refrigerant and in the

production of ious chemicals so these

three important issues are the very

leading factors behind the puncturing of

the ozone layer methy chloroform and the

nitrous oxide we know that while not

hogen containing compound nitrous oxide

n2o can also contribute to Ozone

depletion and at the same time methy

chloroform is a solvent that normally

used in various industrial applications

including cleaning and uh uh degreasing

it can release chlorine atoms when it

reacts with the UV

radiations so impacts of oone layer

depletion increase UV radiation

ecosystem disruption climate change

human health

issues the impact on the materials UV

radiation can degr degrade the materials

such as the Plastics rubber fabric Etc

and health impact apart from Direct

effects on human health like skin cancer

and the cataracts increased UV radiation

can exer respiratory conditions such as

asthma and lead to other health issues

like sunburn premature aging of the skin

and immune sups etc etc uh obvious ly

the UV radiation increased UV radiation

acts as Earth's natural sunscreen so the

ozone layer is actually acting as the

Art's natural sunscreen and this

increased UV radiation can definitely be

harmful for this and depletion of this

layer leads to more UV radiation

ecosystem disruptions as well we have

talked about so uh this was the

discussion thank you for hearing me and

this is uh the discussion for this uh

topic thank you listeners

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