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Earth and Space - Sustainability and Human Impact on Earth

Grade 5IB

Review the key concepts, formulae, and examples before starting your quiz.

🔑Concepts

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Sustainability is the practice of using natural resources in a way that meets current needs without compromising the ability of future generations to meet theirs.

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The Greenhouse Effect occurs when gases such as Carbon Dioxide (CO2CO_2), Methane (CH4CH_4), and Nitrous Oxide (N2ON_2O) trap heat in the Earth's atmosphere, leading to Global Warming.

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Natural resources are categorized into renewable (e.g., solar, wind, H2OH_2O) and non-renewable (e.g., fossil fuels like coal and oil).

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Deforestation reduces the number of trees available to perform photosynthesis, a process where plants absorb CO2CO_2 and release O2O_2.

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The 'Ecological Footprint' measures the impact of human activities on the Earth's ecosystems, represented by the amount of land and water required to support a specific lifestyle.

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Pollution affects the biosphere in three main ways: Air (excess CO2CO_2 and particulate matter), Water (chemical runoff and plastics in H2OH_2O), and Land (waste accumulation in landfills).

📐Formulae

I=P×A×TI = P \times A \times T

6CO2+6H2O+light energy→C6H12O6+6O26CO_2 + 6H_2O + \text{light energy} \rightarrow C_6H_{12}O_6 + 6O_2

Waste Reduction=Initial Waste−(Recycled+Reused)\text{Waste Reduction} = \text{Initial Waste} - (\text{Recycled} + \text{Reused})

💡Examples

Problem 1:

A small town produces 5000 kg5000\text{ kg} of plastic waste per month. If the community starts a recycling program that successfully recovers 40%40\% of this waste, how much plastic is still sent to the landfill?

Solution:

5000 kg−(5000×0.40)=3000 kg5000\text{ kg} - (5000 \times 0.40) = 3000\text{ kg}

Explanation:

To find the remaining waste, we calculate the amount recycled (40%40\% of 5000=2000 kg5000 = 2000\text{ kg}) and subtract it from the total production. This demonstrates the impact of 'Recycling' in the 33 Rs.

Problem 2:

Explain why the increase of CO2CO_2 in the atmosphere contributes to rising sea levels.

Solution:

Higher CO2CO_2 concentrations →\rightarrow increased Greenhouse Effect →\rightarrow higher global temperatures →\rightarrow melting of polar ice caps and thermal expansion of H2OH_2O.

Explanation:

As the Earth warms due to trapped heat, land-based ice melts into the ocean and the volume of water expands as it heats up, causing sea levels to rise.

Problem 3:

Identify the chemical notation for the primary greenhouse gas produced by burning fossil fuels.

Solution:

CO2CO_2 (Carbon Dioxide)

Explanation:

When carbon-based fuels (like coal or gasoline) are burned in the presence of oxygen, they release CO2CO_2 as a byproduct, which is a major contributor to human-induced climate change.

Sustainability and Human Impact on Earth Revision - Grade 5 Science IB