Human beings are in the process …

Human beings are in the process of dramatically reshaping the Earth’s ecosystems. As far back as the 19th century, some scientists have noted that the current era is defined mainly by the impact of human activity. Now, there is an emerging consensus among Earth scientists that we have indeed entered a new period of geological time, the Anthropocene epoch. Scientists who study the history of the Earth usually divide geological time according to major changes to the biology and climate of the Earth. For instance, the ancient Cambrian period, some 500 million years ago, is distinguished by a sudden explosion in the diversity of life, including the emergence of the ancestors of many modern species. More recently, the Pleistocene epoch, which ended about ten thousand years ago, is notable for the glaciers that swept over much of the Earth. The new Anthropocene epoch would be distinguished from all earlier times in Earth’s history by the dramatic impacts of human activity on the Earth. Though Earth scientists debate exactly when the Anthropocene began, there is a clear consensus that human changes to the environment are real and extreme. For one, many life forms have become, and are becoming, extinct as a result of human activity. For this reason, some paleontologists argue that the human impacts of the Anthropocene began at the end of the last Ice Age, around ten thousand years ago. The fossil record indicates that around that time, many large animals, like woolly mammoths and giant sloths, went extinct shortly after humans arrived in their ranges. Their sudden disappearance suggests that habitat destruction and overhunting by humans may have contributed to their demise. Indeed, many large animals, like elephants and gorillas, are endangered for those same reasons today. The pace of human-caused extinctions has only increased in the past several hundred years. The growth and spread of human populations, caused by advances in seafaring technology and agriculture, has led to overexploitation of fragile ecosystems, introduction of invasive species, and pollution, causing many extinctions. Scientists have estimated the rate of extinction by studying the fossil record, monitoring existing species, and using statistical models to estimate the number of undiscovered species that have been lost. Estimates vary, but most scientists believe that diverse species are going extinct at hundreds or thousands of times the natural rate. The International Union for the Conservation of Nature, for instance, has found that, of species surveyed on its “Red List,” about a fifth of all mammals and reptiles and nearly a third of amphibians are in danger of extinction.   This ongoing, rapid loss of species has been described as a mass extinction, as severe as the event that wiped out the dinosaurs 65 million years ago. To some ecologists, this steep decline in biodiversity suggests that the Anthropocene epoch began in the 17th and 18th centuries, when the rate of extinction shot up dramatically. Human activity is also altering the climate as a whole. Since the Industrial Revolution of the 18th and 19th centuries, humans have significantly altered the atmosphere by mining and burning fossil fuels such as coal, oil, and natural gas. Some byproducts of the use of these fuels, like carbon dioxide, are greenhouse gases that trap solar energy on Earth. To assess the impact of these greenhouse gases on the Earth, scientists have had to investigate the history of the Earth’s climate. Ice cores, samples of ice layers that have trapped atmospheric chemicals over time, have supplied scientists with millennia of year-by-year information about greenhouse gas concentrations and atmospheric temperature. Evidence from ice cores clearly show that the Industrial Revolution brought about a sudden jump in carbon dioxide in the atmosphere, along with an increase in temperatures. A scientific consensus exists that this ongoing rise in temperatures has resulted in warming of the oceans, rising sea levels, and more frequent extreme weather events. Thus, some climatologists propose that the Anthropocene’s onset occurred with the Industrial Revolution and its effects on Earth’s atmosphere. Whenever the Anthropocene is judged to have begun, its impact is undeniable. Human activity has changed the face of the planet; the global ecosystem has been and is being reshaped, the composition of the atmosphere has been altered, and even weather patterns are changing in response to human activity. The consequences of these changes will affect life on Earth for millions of years to come, leaving a mark of human activity that may well outlive humanity itself. Questions 1. On the basis of your reading of the passage. answer the following questions by choosing the most appropriate option. The main purpose of the passage is to (1x5=5) (a) respond to controversial claims made by rival scientists (b) argue for potential solutions to the problems posed by climate change 05 (c) describe human impacts on the Earth's environment (d) account for recent changes in global biodiversity (i) The author's tone of writing in this passage is that of (a) an uncertain scientist (b) a concerned observer (c) a jaded sceptic (d) a dejected defeatist (i) The purpose of the second paragraph is to (a) provide a broad description of the Earth's history (b) compare the current geological epoch to the Cambrian period (c) describe the origins of the majority of the Earth's biodiversity (d) explain how scientists divide geological time (iu) Based on the passage, the relationship between carbon dioxide and ice cores is that... (a) carbon dioxide is extracted from ice cores to fuel industrial processes. (b) carbon dioxide destroys ice cores, leading to a loss of a source of information (c) ice cores can be studied to track changes in atmospheric carbon dioxide levels (d) ice cores remove carbon dioxide from the atmosphere, reducing its effects on the climate (e) The passage most strongly suggests that (a) the recent increase in the extinction rate occurred as a result of human-caused climate change (b) all extinctions currently taking place result from human activity (c) some life forms are going extinct before being discovered by humans (d) modern extinctions are destroying the biodiversity generated in the Cambrian period II. Answer the following questions as briefly as (7×7=7) possible. () What is the name of the new period of geological time that Earth has entered in the current era? (i) What was the ancient Cambrian period distinguished by? (ii) What was the probable reason for the woolly mammoths and giant sloths becoming extinct? (iv) According to IUCN, what proportion of animals is in danger of extinction? (v) What are ice cores? (vi) What does evidence from ice cores show about the impact of the Industrial Revolution? (u) Find the words in the given passage which convey the meaning similar to significant (para 2) • investigated (para 4). Please answer this question

Read the following passage given below and answer the questions the follow: The Great wall of China was built to link existing fortifications into a united defense system and better keep invading Mongol tribes out of china. It is the largest man-made monument ever to have been built and it is said that it is the only one visible from space. Many thousands of people must have given their lives to build this huge construction. The great wall of china is a series of towers made of stone, brick, earth, wood and other materials, generally built along an east-to- west line across the historical northern borders of china to protect the Chinese states and empires against the raids and invasions of the various nomadic groups of the Eurasian Steppe. Several walls were being built as carly as the 7th century BCE, these later joined together and made bigger and stronger, are now collectively referred to as the Great wall Especially famous is the wall built (220-206 BCE) by Qin shi Huang, the first Emperor of China. Little of that wall remains. Since then, the great wall has on and off been rebuilt, maintained and enhanced, the majority of the existing wall is from the ming dynasty (1368-1644) other purposes of the Great wall have included border controls, allowing the imposition of duties on goods transported along the silk road, regulation or encouragement of trade and the control of immigration and emigration. Furthermore, the defensive characteristics of the Great Wall were enhanced by the construction of watch towers, troop barracks, gharrison stations, signaling capabilities through the means of smoke or fire and the fact that the path of the Great wall also served as a transportation corridor. The Great wall stretches from Dandong in the cast to Lop Lake in the west, along an are that roughly delineates the southern edge of Inner Mongolia. A comprehensive archaeological survey, using advanced technologies, has concluded that the Ming walls measure 8,850 km. This is made up of 6,259 km sections of actual wall, 359 km of trenches and 2,232 km of natural defensiove barriers such as hills and rivers. Another archaeological survey found that the entire wall with all of its branches measures out to be 21,196km. King Zheng of Qin conquered the last of his opponents and unified china as the First Emperor of the Qin Dynasty Qin shi Huang in 221 BCE. Intending to impose centralized rule and prevent the resurgence of feudal lords, he ordered the destruction of some sections of the walls, however, he ordered building of new walls to connect the remaining fortifications along the empire's northern frontier. Transporting the large quantity of materials required for construction was difficult, so builders always tried to use local resources. Stones from the mountains were used over mountain ranges, while earth was used for construction in the plains. The Great wall concept was revived under the Ming dynasty in the 14th century, to gain a clear upper Hand over the Mongolian tribes. 1.1 On the basis of your reading of the above passage make notes on it, using headings and subheadings. Use recognizable abbreviations (Wherever necessary, minimum four) and a format you consider suitable. Also supply an appropriate title to it. 1.2 Write a summary of the passage in about 50 words.

The theme of the story we are not afraid to die brings out the important of having confidence and making optimum use of our potential elaborating an occurrence from the text to inspire the audience to challenge hurdles of life

Describe the arrival of the gold Finch to the laburnum tree?

Why couldn't the narrator reconcile the fact that his grandmother was once young and pretty? The portrait of a lady class 11

Why is the first meeting described by author in vain ? From the address

It takes 64 muscles to frown and 13 to smile. So, why overwork yourself by frowning. So said report by some US psychiatrists, and that set me on my nerve racking mission of spotting smiling faces among the sea of humanity. I had not noticed till then how is our national need to smile dispelling all gloom. make note and summarize it.

Bbc class 11 module 2 ca9

Why did the grandmother hate music

He had no premonition that this night call would prove unusual, still less that it would influence his whole future in blainelly".what was the unusual event for him ?

theme of the story we are not afraid to die brings out the important of having confidence and making optimum use of our potential elaborating an occurrence from the text to inspire the audience to challenge hurdles of life