Greenhouse Effect and Global Warming Questions in English

(D) Carbon dioxide $(CO_2)$ is a primary greenhouse gas that traps heat in the Earth's atmosphere.
An increase in the concentration of $CO_2$ leads to an enhanced greenhouse effect,which results in global warming.
Therefore,a $25\%$ increase in $CO_2$ levels will significantly contribute to the greenhouse effect and subsequent climate change.

(D) The greenhouse effect is caused by the accumulation of greenhouse gases in the atmosphere, which trap heat from the Earth's surface.
Among the given options, $Methane$ $(CH_4)$ is a potent greenhouse gas.
Other major greenhouse gases include Carbon dioxide $(CO_2)$, Nitrous oxide $(N_2O)$, and Chlorofluorocarbons $(CFCs)$.
Therefore, the correct option is $(d)$.

(B) $CO_2$ acts as a greenhouse gas in the earth's atmosphere.
It traps the infrared radiation emitted by the earth's surface,which is known as the greenhouse effect.
This process acts as an insulator,preventing heat from escaping into space and keeping the earth's surface warm.
If there were no $CO_2$,the heat would escape into space,leading to a significant decrease in the earth's surface temperature compared to the present.

(B) $CO_2$ acts as a greenhouse gas in the earth's atmosphere. It traps infrared radiation reflected from the earth's surface,acting as an insulator that prevents heat from escaping into space. Therefore,in the absence of $CO_2$,the greenhouse effect would be significantly reduced,causing the earth's surface temperature to be lower than the present level.

(D) The correct answer is $D$. The increase in the concentration of greenhouse gases (such as $CO_2$,$CH_4$,$CFCs$,and $N_2O$) leads to global warming by trapping heat in the atmosphere. This rise in temperature causes the melting of polar ice caps and glaciers,which results in a significant rise in sea levels. Consequently,coastal regions and low-lying areas across the globe are at risk of being submerged under water.

(D) The greenhouse effect is a natural phenomenon that warms the earth's surface.
It is primarily caused by greenhouse gases that trap heat in the atmosphere.
Among these,$CO_2$ (carbon dioxide) is the most significant contributor,accounting for approximately $50\%$ of the increase in global temperature.
Other gases like chlorofluorocarbons (CFCs) contribute about $20\%$,while methane and nitrous oxide also play roles.
Therefore,the presence of a $CO_2$ layer in the atmosphere is the primary driver of the greenhouse effect.

(A) The phenomenon where atmospheric gases like $CO_2$,water vapour,and other greenhouse gases trap the infrared radiation (heat) reflected from the Earth's surface is known as the greenhouse effect.
This process prevents the heat from escaping into space,thereby warming the Earth's atmosphere.
Therefore,the correct option is $A$.

(D) The correct answer is $(d)$. The $USA$ is historically and currently one of the largest emitters of greenhouse gases due to its high industrial activity,extensive transportation networks,and massive consumption of fossil fuel energy.

(D) The greenhouse effect is a natural process that warms the earth's surface.
When the sun's energy reaches the earth's atmosphere,some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.
An increase in the concentration of greenhouse gases like $CO_2$,$CH_4$,$CFCs$,and $N_2O$ due to human activities has led to an enhanced greenhouse effect,which results in global warming or the warming of the earth.

(D) The correct answer is $D$. The phenomenon where atmospheric gases like $CO_2$,ozone,and water vapour trap infrared radiation (heat) reflected from the Earth's surface and prevent it from escaping into space,thereby warming the atmosphere,is known as the greenhouse effect.

(B) Greenhouse gases are gases in the atmosphere that trap heat.
$CO_2$ (Carbon dioxide) is the primary greenhouse gas emitted through human activities such as deforestation and the burning of fossil fuels.
$CO$,$H_2$,and $N_2$ do not act as significant greenhouse gases in the context of global warming.

(D) The gases that contribute to the warming of the Earth's atmosphere by trapping heat are known as greenhouse gases.
These gases include Carbon dioxide $(CO_2)$,Methane $(CH_4)$,Chlorofluorocarbons $(CFCs)$,and Nitrous oxide ($N_2O$ or $NO_2$ in some contexts).
This phenomenon is known as the 'greenhouse effect',which leads to global warming.
Therefore,option $D$ is the correct choice.

(C) $CO_2$ concentration is increasing day by day in the atmosphere.
$CO_2$ has the capacity to absorb heat radiation,which leads to an increase in global temperature,a phenomenon known as global warming.

(C) According to the $NCERT$ textbook,the relative contribution of various greenhouse gases to total global warming is as follows:
$1$. $CO_2$: $60\%$
$2$. $Methane$ $(CH_4)$: $20\%$
$3$. $CFCs$: $14\%$
$4$. $N_2O$: $6\%$
Comparing these values with the given options,option $C$ correctly identifies the contribution of $CFCs$ $(14\%)$ and $Methane$ $(20\%)$.

(B) The greenhouse effect is caused by gases that trap heat in the atmosphere.
According to the $NCERT$ textbook,carbon dioxide $(CO_2)$ and methane $(CH_4)$ are the primary contributors to the greenhouse effect.
$CO_2$ contributes approximately $60\%$ to the total global warming,while $CH_4$ contributes about $20\%$.
Therefore,the correct option is $B$.

(C) The greenhouse effect is a natural process that warms the Earth's surface. When the Sun's energy reaches the Earth's atmosphere,some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases. This process maintains the Earth's temperature at a level suitable for life. However,an increase in the concentration of greenhouse gases due to human activities leads to an enhanced greenhouse effect,which results in an increase in the average global temperature,a phenomenon known as $Global \ warming$.

(D) The "Greenhouse Effect" is primarily caused by gases that trap heat in the atmosphere.
According to the $NCERT$ textbook, the relative contribution of various greenhouse gases to global warming is:
$1$. Carbon dioxide $(CO_2)$: $60\%$
$2$. Methane $(CH_4)$: $20\%$
$3$. Chlorofluorocarbons $(CFCs)$: $14\%$
$4$. Nitrous oxide $(N_2O)$: $6\%$
While $CO_2$ and $CH_4$ are the most significant contributors, the question asks for the primary pair. In many standard contexts, $CO_2$ and $CH_4$ are identified as the major greenhouse gases. However, if we look at the options provided, $CO_2$ and $N_2O$ are both significant greenhouse gases listed in the $NCERT$ data. Given the standard curriculum, $CO_2$ and $CH_4$ are the most prominent, but since $CH_4$ was missing in the original options, $CO_2$ and $N_2O$ (Option $D$) is the most scientifically accurate choice among the provided alternatives.

(A) $CO_2$ is a greenhouse gas that traps heat in the Earth's atmosphere,maintaining a temperature suitable for life.
If $CO_2$ were absent,the greenhouse effect would be significantly reduced,leading to a massive loss of heat into space.
Consequently,the Earth's average surface temperature would drop drastically,making the planet much colder and potentially uninhabitable.

(C) The $USA$ (United States of America) is historically and currently one of the largest emitters of greenhouse gases globally due to its high level of industrialization,energy consumption,and transportation sectors. While China has recently surpassed the $USA$ in annual emissions,in the context of standard textbook questions regarding historical and cumulative impact,the $USA$ is frequently cited as the primary contributor.

(C) The melting of ice caps is primarily caused by global warming,which is the gradual increase in the Earth's average temperature.
Global warming is largely driven by the greenhouse effect,where greenhouse gases trap heat in the atmosphere.
$CO_2$ (carbon dioxide) is the most significant greenhouse gas contributing to this phenomenon.
As the concentration of $CO_2$ increases due to human activities like burning fossil fuels and deforestation,the Earth's temperature rises,leading to the melting of polar ice caps.

(D) Greenhouse gases are gases that trap heat in the atmosphere,contributing to the greenhouse effect and global warming.
Common greenhouse gases include:
$1$. Carbon dioxide $(CO_2)$: Primarily released through the burning of fossil fuels and deforestation.
$2$. Methane $(CH_4)$: Released from agricultural practices,landfills,and livestock.
$3$. Nitrous oxide $(N_2O)$: Released from fertilizers and industrial processes.
$4$. Chlorofluorocarbons $(CFCs)$: Synthetic compounds used in refrigeration and aerosols.
Since all the listed options contain greenhouse gases,the most comprehensive answer is $D$.

(B) The greenhouse effect is a natural process that warms the Earth's surface.
When the Sun's energy reaches the Earth's atmosphere,some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.
$CO_2$ (Carbon dioxide) is the primary greenhouse gas responsible for the enhanced greenhouse effect due to human activities like burning fossil fuels and deforestation.
Other greenhouse gases include methane $(CH_4)$,chlorofluorocarbons $(CFCs)$,and nitrous oxide $(N_2O)$.

(C) Global warming is primarily caused by the increase in greenhouse gases like $CO_2$ in the atmosphere.
$1$. Reducing deforestation helps in maintaining forest cover,which acts as a carbon sink by absorbing $CO_2$ through photosynthesis.
$2$. Cutting down the use of fossil fuels (like coal,oil,and natural gas) reduces the emission of $CO_2$ and other greenhouse gases,thereby mitigating the greenhouse effect.
Therefore,option $C$ is the correct method to control global warming.

(B) : Carbon dioxide is a greenhouse gas with a warming effect of $60\%$. Greenhouse gases are essential for keeping the Earth warm and hospitable. They prevent a substantial part of long-wave radiations emitted by the Earth from escaping into space and radiate a part of this energy back to the Earth. This phenomenon is called the greenhouse effect. Because of the greenhouse effect,the mean annual temperature of the Earth is $15^{\circ}C$. Recently,the concentration of greenhouse gases has started rising,which is resulting in an increase in the mean global temperature. This is called global warming. Deforestation has reduced carbon dioxide assimilation,causing excess $CO_2$ to remain in the air. Excessive use of fossil fuels is adding more $CO_2$ to the atmosphere,which intensifies the greenhouse effect.

(D) The correct answer is $D$.
Greenhouse gases are gases that trap heat in the atmosphere, contributing to the greenhouse effect and global warming.
$CO_2$ (Carbon dioxide) is the primary greenhouse gas, primarily released from the burning of fossil fuels in power plants and vehicles.
$N_2O$ (Nitrous oxide) is another significant greenhouse gas with a global warming potential approximately $310$ times greater than that of $CO_2$ over a $100$-year period.
$N_2O$ is naturally produced in the soil through microbial processes like nitrification and denitrification, and its concentration is increasing due to agricultural activities.
Therefore, the pair $CO_2$ and $N_2O$ represents the major contributors to the greenhouse effect.

(A) The relative contribution of various greenhouse gases to global warming is as follows: $CO_2$ $(50\%)$,$CFCs$ $(20\%)$,$CH_4$ $(16\%)$,$O_3$ $(8\%)$,and nitrous oxide ($N_2O$,$6\%$).
Based on these values,$CO_2$ $(50\%)$ and $CFCs$ $(20\%)$ are the two highest contributors. However,in many standard contexts,$CO_2$ and $CH_4$ are often cited as the primary contributors due to their widespread presence and impact. Given the options provided,$CO_2$ and $CH_4$ represent the most significant contributors among the choices listed.

(C) The greenhouse effect is a natural process that warms the Earth's surface.
Without the greenhouse effect, the Earth's atmosphere would not trap heat, leading to a much colder environment.
The average temperature of the Earth's surface in the absence of the greenhouse effect is estimated to be $ -18 \, ^\circ C $.
In contrast, the current average temperature of the Earth's surface, maintained by the greenhouse effect, is approximately $ 15 \, ^\circ C $.
Therefore, the correct values are $ -18 \, ^\circ C $ and $ 15 \, ^\circ C $.

(A) The relative contribution of various greenhouse gases to global warming is as follows:
$1$. Carbon dioxide $(CO_2)$: $60\%$
$2$. Methane $(CH_4)$: $20\%$
$3$. Chlorofluorocarbons $(CFCs)$: $14\%$
$4$. Nitrous oxide $(N_2O)$: $6\%$
Comparing these values with the given options, option A correctly represents the proportions: $60\%\ CO_2, 20\%\ \text{Methane}, 14\%\ CFCs, 6\%\ N_2O$ is the standard NCERT data. Since the provided options contain errors in matching the standard data, we identify the closest logical structure or correct the sequence.

(B) The relative contribution of various greenhouse gases to global warming is as follows:
$1$. Carbon dioxide $(CO_2)$: $60\%$
$2$. Methane $(CH_4)$: $20\%$
$3$. Chlorofluorocarbons $(CFCs)$: $14\%$
$4$. Nitrous oxide $(N_2O)$: $6\%$
Comparing these values with the given options,the correct pair is $CFC - 14\%$.

(A) The greenhouse effect is caused by various gases in the atmosphere that trap heat. According to the standard data provided in the $NCERT$ textbook for Environmental Issues,the relative contributions of various greenhouse gases to global warming are as follows:
$1$. Carbon dioxide $(CO_2)$: $60\%$
$2$. Methane $(CH_4)$: $20\%$
$3$. Chlorofluorocarbons $(CFCs)$: $14\%$
$4$. Nitrous oxide $(N_2O)$: $6\%$
Therefore,$CFCs$ contribute $14\%$ to the greenhouse effect.

(C) Greenhouse gases,such as $CO_2$,are responsible for the greenhouse effect.
These gases have the property of allowing short-wave solar radiation to pass through the atmosphere to reach the Earth's surface.
However,they absorb the long-wave infrared $(IR)$ radiation emitted by the Earth's surface.
By trapping this heat and reflecting it back towards the Earth,they prevent it from escaping into space,thereby warming the planet.

(C) The greenhouse effect is a natural phenomenon that warms the Earth's surface. When the Sun's energy reaches the Earth's atmosphere,some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases. The primary greenhouse gases include $CO_2$,methane,and water vapor. An increase in the concentration of $CO_2$ in the atmosphere traps more heat,leading to global warming. Therefore,the greenhouse effect is considered a warning due to the rise in global temperatures caused by the accumulation of these gases.

(B) The $USA$ is historically and currently one of the largest contributors to global greenhouse gas emissions due to its high level of industrialization,energy consumption,and transportation infrastructure. While other countries like China have recently surpassed the $USA$ in annual emissions,in the context of standard biology and environmental science textbooks,the $USA$ is frequently cited as a major contributor.

(B) $CO_2$ is a major greenhouse gas that traps heat in the Earth's atmosphere,a phenomenon known as the greenhouse effect.
This effect is essential for maintaining the Earth's surface temperature within a range suitable for life.
Without $CO_2$,the greenhouse effect would be significantly reduced,causing heat to escape into space.
Consequently,the Earth's surface temperature would be much lower than it is currently.

(D) The greenhouse effect is a natural process that warms the Earth's surface.
When the Sun's energy reaches the Earth's atmosphere,some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.
These gases,such as $CO_2$,$CH_4$,and water vapor,trap heat in the atmosphere,thereby maintaining the Earth's temperature at a level suitable for life.
Without this effect,the Earth would be too cold to support life as we know it.

(A) The greenhouse effect is primarily caused by various gases in the atmosphere. According to the $NCERT$ textbook, the relative contributions of these greenhouse gases to global warming are as follows:
$1$. Carbon dioxide $(CO_2)$: $60\%$
$2$. Methane $(CH_4)$: $20\%$
$3$. Chlorofluorocarbons $(CFCs)$: $14\%$
$4$. Nitrous oxide $(N_2O)$: $6\%$
Comparing these values with the given options, option $A$ $(CFC - 14\%, \text{Methane} - 20\%)$ correctly identifies the proportions for these two gases.

(A) The greenhouse effect is caused by gases that trap heat in the Earth's atmosphere.
According to the data provided in the $NCERT$ textbook,the relative contribution of various greenhouse gases to global warming is as follows:
$1$. Carbon dioxide $(CO_2)$: $60\%$
$2$. Methane $(CH_4)$: $20\%$
$3$. Chlorofluorocarbons $(CFCs)$: $14\%$
$4$. Nitrous oxide $(N_2O)$: $6\%$
Therefore,$CO_2$ and $CH_4$ are the two gases that contribute the most to the greenhouse effect.

(D) The 'Greenhouse Effect' is a natural phenomenon that warms the Earth's surface.
When the Sun's energy reaches the Earth's atmosphere,some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.
The major greenhouse gases contributing to this effect include Carbon dioxide $(CO_2)$,Methane $(CH_4)$,Chlorofluorocarbons $(CFCs)$,and Nitrous oxide $(N_2O)$.
Among the given options,$CO_2$ and $N_2O$ are primary contributors to the greenhouse effect.
Therefore,the correct group is $CO_2$ and $N_2O$.

(D) The greenhouse effect is a natural process that warms the Earth's surface.
When the Sun's energy reaches the Earth's atmosphere,some of it is reflected back to space and the rest is absorbed and re-radiated by greenhouse gases.
$CO_2$ (Carbon dioxide) and $CH_4$ (Methane) are the primary greenhouse gases contributing to global warming.
$CO_2$ accounts for about $60\%$ of the total greenhouse effect,while $CH_4$ accounts for about $20\%$.
Therefore,the correct pair is Carbon dioxide and Methane.

(A) Greenhouse gases contribute to global warming by trapping heat in the atmosphere.
According to the relative contribution to the greenhouse effect,carbon dioxide $(CO_2)$ accounts for approximately $60\%$ of the total greenhouse effect,while methane $(CH_4)$ accounts for approximately $20\%$.
Therefore,these two gases are the primary contributors to the greenhouse effect.

(N/A) Global warming is defined as an increase in the average temperature of the Earth's surface.
Causes of global warming:
Global warming occurs due to the increased concentration of greenhouse gases in the atmosphere,such as $CO_2$,$CH_4$,and water vapour. These gases trap solar radiation reflected by the Earth. While this natural greenhouse effect is essential for survival,an excessive increase in these gases due to industrialization,burning of fossil fuels,and deforestation leads to global warming.
Effects of global warming:
Over the past three decades,the Earth's average temperature has increased by $0.6\,^{\circ}C$. This rise disrupts the natural water cycle,alters rainfall patterns,and changes precipitation levels. Furthermore,it causes the melting of polar ice caps and mountain glaciers,leading to a rise in sea levels and the subsequent inundation of coastal regions.
Control measures:
$1$. Reducing the use of fossil fuels.
$2$. Promoting the use of bio-fuels.
$3$. Improving energy efficiency.
$4$. Utilizing renewable energy sources such as $CNG$.
$5$. Reforestation (planting more trees).
$6$. Recycling materials to reduce waste and energy consumption.

(B) The term "Greenhouse" was originally used for a small glass house.
This structure is used to grow plant seedlings during cold seasons.
The glass panels allow sunlight to enter but prevent heat from escaping, which keeps the interior of the greenhouse warm.
This mechanism maintains a suitable temperature for the growth of plants.

(B) Greenhouse gases have led to considerable heating of the Earth,leading to global warming.
$\Rightarrow$ During the past century,the temperature of the Earth has increased by $0.6^{\circ}C$,most of it during the last $3$ decades.
This rise in temperature leads to deleterious changes in the environment and results in odd climatic changes (e.g.,$El$ $Nino$ effect).
This causes the melting of ice caps as well as other places like Himalayan snow caps.

(N/A) Global warming refers to the gradual increase in the average temperature of the Earth's atmosphere due to the greenhouse effect.
$1$. Causes: The primary cause is the increase in the concentration of greenhouse gases $(GHGs)$ such as $CO_2$,$CH_4$,$CFCs$,and $N_2O$ in the atmosphere. These gases trap solar radiation (infrared rays) reflected from the Earth's surface. Human activities like deforestation,burning of fossil fuels,and industrial processes significantly contribute to this increase.
$2$. Effects: The rise in global temperature leads to deleterious changes in the environment,such as the melting of polar ice caps and glaciers,which causes a rise in sea levels. This threatens coastal regions with flooding. It also results in unpredictable weather patterns,such as increased frequency of droughts,floods,and storms,and negatively impacts biodiversity and agricultural productivity.
$3$. Control: Global warming can be controlled by:
$(a)$ Reducing the use of fossil fuels and shifting to renewable energy sources like solar and wind energy.
$(b)$ Improving energy efficiency in industries and transportation.
$(c)$ Reforestation and afforestation to increase carbon sequestration.
$(d)$ Reducing deforestation and limiting the emission of $GHGs$ through international agreements and policies.

(N/A) As the concentration of greenhouse gases increases,the Earth's temperature rises,leading to global warming.
An increase in temperature causes harmful changes in the atmosphere.
Ice in polar regions and the Himalayan regions begins to melt.
If this continues for a long time,the sea level rises,which causes coastal areas to become submerged.

(N/A) Global warming is the increase in the Earth's temperature due to the rise in the concentration of greenhouse gases like $CO_2, CH_4,$ and $CFCs$ in the atmosphere.
Effects: $(i)$ The increase in temperature causes the melting of polar ice caps,leading to a rise in sea levels.
$(ii)$ Global warming leads to explosive weed growth,increased plant diseases,and higher pest populations. These factors result in reduced crop yields in tropical and subtropical regions.
Control Measures: $(i)$ Reduce deforestation and promote reforestation.
$(ii)$ Plant more trees.
$(iii)$ Limit the use of fossil fuels by utilizing alternative sources of energy.
$(iv)$ Control the human population growth.

(N/A) prominent greenhouse gas is $Carbon \ dioxide \ (CO_2)$.
Its primary source of large-scale production is the combustion of fossil fuels (coal,oil,and natural gas) in industries,power plants,and automobiles,as well as large-scale deforestation.
The harmful effects of $CO_2$ include:
$1$. Global Warming: It traps heat in the atmosphere,leading to an increase in the Earth's average temperature.
$2$. Climate Change: It causes melting of polar ice caps,rising sea levels,and unpredictable weather patterns.
$3$. Ecological Imbalance: It disrupts ecosystems,leading to the loss of biodiversity and habitat destruction.