Enviro course notes

• The seven continents on Earth are:

  • Europe
  • Africa
  • North America
  • South America
  • Asia
  • Oceania
  • Antarctica

  Antarctica is governed under the Antarctic Treaty, signed by 12 nations, including the United Kingdom
• The five oceans that cover over 70% of the planet are:

  • Atlantic Ocean
  • Pacific Ocean
  • Indian Ocean
  • Southern Ocean
  • Arctic Ocean

  The nearest ocean to the UK is the Atlantic Ocean, the second largest of the five oceans
• The Brandt line historically divided the planet into the rich north and the poor south, but it is now considered too simplistic due to changes in the world
• The World Bank classifies countries based on income levels:

  • Low-income countries (LIC) have a GNI per capita of $1,045 or less
  • Medium-income countries (MIC) have a GNI per capita of more than $1,045 but less than $12,746
  • High-income countries (HIC) have a GNI per capita above US$ 12,746
• Sustainability involves meeting present needs while protecting the environment and resources for the future
• Agreements like 'Agenda 21' and 'Local Agenda 21' aim to make resource usage more sustainable by:

  • Conserving resources
  • Using local materials
  • Involving local people
  • Using appropriate technology
• The water cycle, also known as the hydrological cycle, involves processes like evaporation, condensation, and precipitation
• The Earth's atmosphere is divided into five main layers: exosphere, thermosphere, mesosphere, stratosphere, and troposphere
• Greenhouse gases like carbon dioxide and methane impact global temperature by allowing more solar radiation to enter the atmosphere and trapping heat within it
• Ecosystem components include biotic (living) and abiotic (non-living) factors, populations, communities, biomes, habitats, niches, food chains, and photosynthesis
• Consumers in an ecosystem can be categorized into primary, secondary, and tertiary consumers
• Decomposers in an ecosystem derive their food from the bodies of dead organisms
• A food web is a diagram showing the relationship between producers, primary, secondary, and tertiary consumers in an ecosystem
• A pyramid of numbers is a diagram representing the numbers of organisms at each trophic level in an ecosystem
• Trophic level refers to a feeding level within a food chain or web
• Chlorophyll is the green pigment in plants that traps light energy
• Respiration is the process by which living things release energy from food to carry out life processes
• Pollen grain is the structure in plants that contains the male sex cell, carried to the female organ by pollination
• Abiotic factors in an ecosystem include temperature, humidity, water, oxygen, salinity, light, and pH
• Temperature is usually expressed in degrees centigrade and affects the distribution of species in different environments
• Humidity is a measure of how damp the air is and can range from 0% in dry desert environments to 100% in humid rainforests
• Water is essential for all life and is a raw material for photosynthesis and a medium for chemical reactions
• Oxygen is essential for living organisms and its levels can vary in different environments
• Salinity, measured in parts per million or parts per thousand, affects aquatic animals and plants living in saline environments
• Light is essential for photosynthesis and nearly all living things depend on it
• pH is a measure of how acid or alkaline water or a solution is, affecting the survival of plants and animals
• Photosynthesis is the process by which plants trap light energy from the Sun to produce glucose
• Plants use glucose for respiration to release energy and to make other substances like starch, cellulose, and proteins
• Living things interact through competition, predation, and pollination in various ecosystems
• Energy flows through ecosystems, with chemical energy being converted into heat and minerals cycling around ecosystems
• Plants store light energy as chemical energy in sugars and other substances they make
• Plants get the energy they need for their life processes from a process called respiration
• The overall equation for respiration is: glucose + oxygen ➔ carbon dioxide + water + (energy)
• During respiration, glucose and oxygen are used up, and water and carbon dioxide are produced as waste products
• Only about 10% of the energy fixed from sunlight by a plant is available to a consumer
• After just two steps in the energy flow, the amount of energy available to a consumer is only 1% of that available from the Sun
• Food chains never have more than four or five links because there is not enough energy left to support another trophic level
• Energy flow can be shown in a simple diagram, forming a pyramid of energy
• Consumers acquire minerals they need from the level below, including carbon, oxygen, sulfur, phosphorus, and nitrogen
• Carbon cycle:

  • Reservoir: carbon dioxide in the atmosphere
  • Fixation: by photosynthesis
  • Carbon is found in living things in carbohydrates, proteins, fats, and other chemicals
  • Carbon is removed from living things by respiration, returning carbon dioxide to the atmosphere