Deforestation & Afforestation Video Lecture | Science Class 8

0:0:0: if you watch the news you might have
0:0:2: come across headlines like our sea level
0:0:5: is rising or something like our Earth is
0:0:7: getting warmer every year have you ever
0:0:10: thought about why things like these are
0:0:13: happening let's look at these
0:0:16: pictures here you can see there was a
0:0:18: very big green forest before but now
0:0:21: there is a big desert here now look at
0:0:24: this photo there was a big river here
0:0:26: but now it's all dried up what is the
0:0:30: cause of all this yes
0:0:34: deforestation deforestation is a cutting
0:0:36: down of a large number of trees and
0:0:39: clearing up
0:0:40: forests but why do people cut down trees
0:0:44: what are the reasons behind
0:0:47: deforestation yes there can be many but
0:0:49: let's look at some major reasons here
0:0:53: the first one is procuring land for
0:0:55: cultivation humans need food to survive
0:0:58: and as the population grows so does the
0:1:0: demand for food to grow more crops
0:1:4: humans convert Forest lands into
0:1:6: agricultural lands by cutting down trees
0:1:10: the second reason is building houses and
0:1:12: factories humans also need shelter and
0:1:15: jobs and as more people move from rural
0:1:18: to urban areas the demand for housing
0:1:20: and industries
0:1:22: increases to build more structures
0:1:24: humans clear forests and use that land
0:1:27: for
0:1:28: construction the Third third reason is
0:1:30: making furniture or using wood as fuel
0:1:33: humans like to have comfortable and
0:1:35: beautiful things such as tables chairs
0:1:38: beds and
0:1:40: cabinets to make these things humans use
0:1:43: wood which comes from trees and the
0:1:46: demand for wood is increasing rapidly to
0:1:49: get more wood humans cut down more trees
0:1:53: another reason is mining for mining of
0:1:56: minerals a large area of land is needed
0:2:0: so people cut down
0:2:2: forests and finally forest fires and
0:2:5: severe droughts sometimes deforestation
0:2:8: happens due to natural causes such as
0:2:11: forest fires and severe
0:2:13: droughts these natural disasters can
0:2:16: destroy vast areas of forest land
0:2:18: leaving behind nothing but empty land so
0:2:22: we looked at the five major reasons for
0:2:25: deforestation now that we know what
0:2:28: deforestation is and why it happens
0:2:30: let's see what are the consequences of
0:2:33: deforestation how does deforestation
0:2:36: affect the
0:2:37: environment let's find out deforestation
0:2:41: has many negative impacts on the
0:2:43: environment such as global warming one
0:2:47: major consequence of deforestation is
0:2:50: the global
0:2:51: warming now as you know trees absorb
0:2:54: carbon dioxide while
0:2:56: respiration and release oxygen carbon
0:3:0: dioxide is a greenhouse gas which means
0:3:3: it traps the heat on Earth so when trees
0:3:6: are cut down there will be more carbon
0:3:9: dioxide in the atmosphere which traps
0:3:11: more heat and causes global
0:3:13: warming global warming can lead to many
0:3:16: problems such as the melting of ice caps
0:3:19: because of which sea level rises and it
0:3:22: can cause
0:3:23: floods another Major Impact of
0:3:25: deforestation is soil erosion we know
0:3:28: that trees have roots and now these
0:3:31: roots are very useful they hold the soil
0:3:34: together now what will happen if there
0:3:36: are no
0:3:37: trees yes the top so of our Earth will
0:3:40: become loose and it can easily fly away
0:3:43: by
0:3:44: winds this is called soil
0:3:46: erosion and when it gets extreme the
0:3:49: soil becomes Barren meaning no plants
0:3:51: can be grown there and this is called
0:3:55: desertification the next one is the
0:3:57: imbalance in the water cycle DeForest
0:3:59: station also affects the water cycle
0:4:2: which is the movement of water between
0:4:4: the Earth and the
0:4:5: atmosphere trees help to maintain the
0:4:8: water cycle by absorbing water from the
0:4:10: ground and releasing water vapor into
0:4:12: the air this creates clouds and
0:4:16: rainfall but when trees are cut down
0:4:18: they can no longer perform this
0:4:21: function this leads to less water waper
0:4:23: in the atmosphere which reduces the rain
0:4:26: and causes
0:4:27: droughts Wildlife impact deforestation
0:4:30: also has a devastating impact on the
0:4:33: wildlife deforestation destroys the
0:4:36: habitats of animals and plants depriving
0:4:39: them of their basic needs this leads to
0:4:42: the extinction of many
0:4:44: species as you can see deforestation is
0:4:47: a serious problem that affects the
0:4:49: environment and the living beings on
0:4:51: Earth therefore we must take steps to
0:4:54: prevent and reduce
0:4:56: deforestation and how will we do that
0:5:0: there is a simple solution to this
0:5:2: problem
0:5:4: reforestation reforestation is the
0:5:6: plantation of a large number of
0:5:9: trees well if we keep cutting down
0:5:11: forests there would be no trees left in
0:5:14: the end so we should plant the same
0:5:17: number of trees that we cut this is
0:5:20: called
0:5:21: reforestation with this we have come to
0:5:24: the end of this video we learned about
0:5:27: deforestation and how it is a very big
0:5:29: threat to our
0:5:31: lives we hope that you have understood
0:5:34: the concept of
0:5:35: deforestation now here's a secret on how
0:5:38: you can study effectively with the urv
0:5:41: app you can learn with chapter notes
0:5:44: watch video lectures and solve ncer
0:5:47: based McQ tests of this chapter on
0:5:50: urv and that's not all you also get
0:5:53: amazing courses for Class 8 and much
0:5:55: more for your class 8
0:5:57: preparation thank you