Human Contributions to Climate Change
Climate change refers to significant, long-term changes in the Earth's climate, especially a rise in global average temperature. Humans contribute to climate change primarily by increasing the concentration of greenhouse gases (GHGs) in the atmosphere, which trap heat and lead to global warming.
Main Human Activities
- Burning Fossil Fuels: Activities such as driving cars, generating electricity, and manufacturing release carbon dioxide ($\mathrm{CO_2}$) and other GHGs.
- Deforestation: Cutting down forests reduces the number of trees that absorb $\mathrm{CO_2}$.
- Agriculture: Farming releases methane ($\mathrm{CH_4}$) and nitrous oxide ($\mathrm{N_2O}$), both potent greenhouse gases.
Worked Example: Calculating Carbon Emissions
Suppose a car burns 10 liters of gasoline. Each liter of gasoline produces about 2.3 kg of $\mathrm{CO_2}$ when burned. How much $\mathrm{CO_2}$ is emitted?
Step 1: Write the formula for total emissions:
$$
\text{Total } \mathrm{CO_2} = \text{Liters burned} \times \text{Emission per liter}
$$
Step 2: Substitute the values:
$$
\text{Total } \mathrm{CO_2} = 10 \times 2.3 = 23 \text{ kg}
$$
Step 3: State the result:
Burning 10 liters of gasoline emits $23$ kg of $mathrm{CO_2}$ into the atmosphere.
Takeaways
- Human activities, especially burning fossil fuels and deforestation, significantly increase greenhouse gas concentrations.
- These gases trap heat, causing global temperatures to rise and altering climate patterns.
- Reducing emissions and protecting forests are key to mitigating human impact on climate change.