Since the Industrial Revolution, how much has the amount of CO2 in the atmosphere increased?a.One-halfb.One-fourthc.One-thirdd.Two-thirds

Break Down the Problem

1. Understand the context: The Industrial Revolution began in the late 18th century, leading to significant increases in carbon dioxide (CO2) emissions due to industrial activities, fossil fuel combustion, and other human-related activities.
2. Identify the current level of CO2 in the atmosphere and its level before the Industrial Revolution.

Relevant Concepts

1. Historical CO2 Levels:
   • Pre-industrial levels of CO2 were approximately 280 parts per million (ppm).
   • Current levels (as of 2021-2023) are around 400 ppm.

Analysis and Detail

1. Calculate the increase in CO2:

   • Increase in CO2 = Current CO2 - Pre-industrial CO2
   • Increase in CO2 = 400 ppm - 280 ppm = 120 ppm.

2. Calculate the fraction of increase relative to pre-industrial levels:

   • Fraction increase = (Increase in CO2) / (Pre-industrial CO2)
   • Fraction increase = 120 ppm / 280 ppm ≈ 0.4286.

3. Convert the fraction to a more relatable term:

   • Approximately 0.43 is close to one-half (0.5).

Verify and Summarize

• The calculations confirm that the increase in CO2 levels since the Industrial Revolution represents nearly one-half of the pre-industrial amount.

Final Answer

The amount of CO2 in the atmosphere has increased by approximately one-half since the Industrial Revolution. Therefore, the answer is a. One-half.