Humans And Their Effects On The Environment
Overview
There are more of us than there have ever been, and each of us now uses more energy, more packaging, more water and more manufactured food than our grandparents did. Every one of those choices leaves something behind. The waste has to go somewhere, and biology is the study of what happens once it gets there: which organisms tolerate it, which ones disappear, and how a gas leaving a chimney in one country can empty a lake in another.
This lesson follows the routes by which human activity reaches living systems: what we release into water, into the air and onto land, what happens when tropical forest is cleared, and what rising carbon dioxide and methane are doing to climate. You will learn to set each of those out as a chain of causes rather than a list of words, and you will practise the skill this section of the specification asks for by name: reading an unfamiliar set of environmental measurements and deciding how much they are actually worth as evidence.
Objectives
- Rapid growth in the human population and an increase in the standard of living mean that increasingly more waste is produced. Unless waste and chemical materials are properly handled, more pollution will be caused.
- Waste may pollute: water, with sewage, fertiliser or toxic chemicals; air, with smoke and gases such as sulfur dioxide, which contributes to acid rain; land, with toxic chemicals such as pesticides and herbicides, which may be washed from land into water
- Large-scale deforestation in tropical areas has led to reduction in biodiversity. Students should be able to describe the effects of deforestation.
- Levels of carbon dioxide and methane in the atmosphere are increasing, and contribute to ‘global warming’. An increase in the Earth’s temperature of only a few degrees Celsius may: cause big changes in the Earth’s climate; cause a rise in sea level; cause changes in migration patterns, eg in birds; result in changes in the distribution of species. Throughout this section, students should be able, when provided with appropriate information: to analyse and interpret scientific data concerning environmental issues; to evaluate methods used to collect environmental data and consider their validity and reliability as evidence for environmental change.
Mind map
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Lesson Note
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Lesson Evaluation
Congratulations on completing the lesson on Humans And Their Effects On The Environment. Now that youve explored the key concepts and ideas, its time to put your knowledge to the test. This section offers a variety of practice questions designed to reinforce your understanding and help you gauge your grasp of the material.
You will encounter a mix of question types, including multiple-choice questions, short answer questions, and essay questions. Each question is thoughtfully crafted to assess different aspects of your knowledge and critical thinking skills.
Use this evaluation section as an opportunity to reinforce your understanding of the topic and to identify any areas where you may need additional study. Don't be discouraged by any challenges you encounter; instead, view them as opportunities for growth and improvement.
- Which gas released by burning fuels that contain sulfur is the main cause of acid rain? A. Carbon dioxide B. Methane C. Sulfur dioxide D. Nitrogen Answer: C
- Which pair of gases is increasing in the atmosphere and contributing to global warming? A. Sulfur dioxide and carbon dioxide B. Carbon dioxide and methane C. Oxygen and nitrogen D. Methane and sulfur dioxide Answer: B
- Which of these is named in the specification as a pollutant of land? A. Sewage B. Sulfur dioxide C. Herbicide D. Smoke Answer: C
- Which of these is NOT a direct effect of large-scale deforestation? A. Reduced biodiversity B. Increased soil erosion C. More frequent flooding D. A fall in atmospheric carbon dioxide Answer: D
- The area of forest in a region falls from 5.0 million hectares to 3.5 million hectares. What is the percentage decrease? A. 15% B. 30% C. 43% D. 70% Answer: B
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