Environmental Issues

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E-Waste

E-waste refers to discarded electronic devices.

Technology is hard to repair

Manufacturers often make technology which is difficult to repair, and so it is sometimes cheaper to replace a product than repair it. This contributes to e-waste.

Newer models

Many consumers will replace a working device with a newer model each year.
- This is unnecessary e-waste.
However, there are services where old devices can be given a new lease of life.
- Some computer parts are finite. Their materials could be repurposed for new parts in new models.

Disposal of e-waste

E-waste can include toxic chemicals.
There are strict rules about the disposal of e-waste imposed by the Waste Electric and Electronic Equipment (WEEE).
To bypass these rules, many organisations send e-waste to countries with fewer regulations - such as China and India.

Energy Consumption

It's no surprise that technology uses a lot of energy. But it might be more than most people think.

Data centres

Data centres are some of the worst offenders for energy consumption.
Not only do the servers need to be powered, but they also need a lot of energy for their cooling systems.

How much energy?

In 2011, the US department for energy calculated that data centres in the US alone need 70 billion kWh of electricity each year.
- To put that in perspective, that's 2% of America's total power consumption.
- It's also the same as leaving over 80 million lightbulbs turned on.

Reducing energy consumption

Energy consumption in data centres can be reduced by using hot and cold aisles. This is making sure that one server's air outtake (hot) does not blow into another server's air intake (cold).
We can also reduce consumption by using server virtualisation.
- This reduces the number of redundant servers by running multiple virtual servers on a single piece of hardware.

Efficiency

On the other hand, large data can predict energy usage trends and ensure there is generally less wasted energy.
- This support can be given to homeowners and businesses to monitor their energy usage more efficiently.
New devices/technology are generally more energy efficient than old models.
- When software replaces physical copies, there is a perceived saving in energy since those physical copies no longer need to be distributed.

Positive Environmental Impact

It's not all bad! There have been some positive impacts.

Climate change

Computer systems have allowed scientists to monitor and predict the effects of climate change.
Use of technology can aid in our understanding of the natural world.

Efficiency

Computer models and simulations have been used to test and improve the efficiency of:
- Engines.
- Wind turbines.

Online communication

Online communication reduces the need for travel for meetings, which reduces the impact of pollution from cars and aeroplanes.

1Computer Systems

1.1Systems Architecture

1.1.1Fetch-Execute Cycle

1.1.2Common CPU Components & Their Function

1.1.3Von Neumann Architecture

1.1.4Factors Affecting CPU Performance

1.1.5Embedded Systems

1.1.6Exam-Style Questions - Von Neumann Architecture

1.1.7Diagnostic Misconceptions - Embedded vs General

1.2Memory & Storage

1.2.1Types of Memory

1.2.2Flash Memory

1.2.3Properties of Flash Memory

1.2.4Running Out of Memory

1.2.5Virtual Memory

1.2.6Units of Capacity

1.2.7Calculating Capacity Requirements

1.2.8Solid State Storage

1.2.9Properties of Solid State Media

1.2.10Magnetic Storage

1.2.11Properties of Magnetic Media

1.2.12Examples of Magnetic Storage

1.2.13Optical Storage

1.2.14Properties of Optical Media

1.2.15Examples of Optical Storage

1.2.16Types of Optical Disk

1.2.17Number Bases

1.2.18Converting Number Bases

1.2.19Hexadecimal

1.2.20Using Hexadecimal

1.2.21Converting Denary & Hexadecimal

1.2.22Binary Addition

1.2.23Binary Shifts

1.2.24Representing Text

1.2.25ASCII & Unicode

1.2.26Representing Images

1.2.27Converting Binary & Images

1.2.28Representing Sound

1.2.29Data Compression

1.2.30Grade 9 - Storage

1.2.31Exam-Style Questions - Primary Memory

1.2.32Exam-Style Questions - Storage

1.2.33Exam-Style Questions - Data Conversions

1.2.34Diagnostic Misconceptions - RAM vs ROM

1.2.35Diagnostic Misconceptions - Bits, Nibbles & Bytes

1.2.36Diagnostic Misconceptions - Bits Required to Store

1.2.37End of Topic Test - Computer Systems

1.2.38End of Topic Test - Representation

1.3Computer Networks, Connections & Protocols

1.4Network Security

1.4.1Forms of Attack

1.4.2Penetration Testing

1.4.3Malware

1.4.4How Malware Spreads

1.4.5Social Engineering

1.4.6Phishing

1.4.7Cracking Passwords

1.4.8Denial of Service Attacks

1.4.9Data Interception

1.4.10Methods of Data Interception

1.4.11SQL Injection

1.4.12Network Administration

1.4.13Network Forensics

1.4.14Protecting Against Malware

1.4.15Firewalls

1.4.16User Access Levels

1.4.17Passwords

1.4.18Encryption

1.4.19End of Topic Test - Networks

1.5Systems Software

1.5.1System Software

1.5.2Utility Software

1.5.3Operating Systems

1.5.4User Interfaces

1.5.5Memory & Process Management

1.5.6File Management

1.5.7Device Management

1.5.8User Management

1.5.9Encryption Software

1.5.10Defragmentation Software

1.5.11Data Compression Software

1.5.12Backup Software

1.6Ethical, Legal, Cultural & Environmental Concern

2Computational Thinking, Algorithms & Programming

2.1Algorithms

2.1.1Computational Thinking - Abstraction

2.1.2Computational Thinking - Decomposition

2.1.3Algorithmic Thinking

2.1.4Pseudocode

2.1.5Flowchart Diagrams

2.1.6Interpreting Algorithms

2.1.7Correcting Algorithms

2.1.8Completing Algorithms

2.1.9Search Algorithms

2.1.10Binary Search

2.1.11Linear Search

2.1.12Overview of Sort Algorithms

2.1.13Bubble Sort

2.1.14Merge Sort

2.1.15Insertion Sort

2.1.16Exam-Style Questions - Sorting Algorithms

2.2Programming Fundamentals

2.3Producing Robust Programs

2.3.1Defensive Design

2.3.2Validation & Sanitisation

2.3.3Authentication & Contingencies

2.3.4Maintainability

2.3.5Purpose of Testing

2.3.6Types of Testing

2.3.7Test Plans

2.3.8Types of Errors

2.3.9End of Topic Test - Programming

2.3.10Exam-Style Questions - Testing

2.4Boolean Logic

2.4.1Binary Systems

2.4.2Logic Circuits

2.4.3Boolean Logic

2.4.4Boolean Operators

2.4.5Grade 9 - Logic

2.5Programming Languages & IDEs

2.5.1High-Level vs Low-Level Languages

2.5.2Translation - Compliers & Interpreter

2.5.3Translation - Assemblers

2.5.4Integrated Development Environments

2.5.5Exam-Style Questions - Translation

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