The assertion that carbon dioxide (CO₂), despite being a small component of the atmosphere, cannot significantly contribute to heating is misleading. While CO₂ constitutes only about 0.04% of the atmosphere^[1], its impact on global warming is substantial due to its role in the greenhouse effect. CO₂, along with water vapor, acts as a cap, hindering the escape of infrared radiation emitted by the Earth’s surface into space. Without these gases, the Earth’s average surface temperature would plummet.

The most common GHGs in the atmosphere include:

• water vapour (H₂O)
• carbon dioxide (CO₂)
• methane (CH₄)
• nitrous oxide (N₂O)
• ozone (O₂)
• chlorofluorocarbons (CFCs)

Water vapor is the most prevalent greenhouse gas in the atmosphere, varying between 40 to 90% based on geographic location^[2].

Despite constituting a small fraction of the atmosphere, CO₂ and water vapor are effective at trapping heat, thereby elevating the planet’s temperature to levels conducive to life. CO₂’s effectiveness in trapping heat is not solely determined by its concentration in the atmosphere, but also by its ability to absorb and emit infrared radiation. Even though water vapor is the dominant greenhouse gas, CO₂’s ability to absorb infrared radiation is significant, especially considering its distribution throughout the atmosphere. Unlike water vapor, which has “windows”^[3] allowing some infrared energy to escape, CO₂ is well-mixed in the atmosphere, extending its influence to higher altitudes where it effectively traps heat.

The burning of fossil fuels has led to a substantial increase in atmospheric CO₂ levels, from about 288 ppm before the industrial revolution to approximately 414 ppm today, disrupting the Earth’s heat balance and contributing to global warming.

In conclusion, while CO₂ may constitute a small fraction of the atmosphere, its impact on global warming is profound. As human activities continue to increase CO₂ emissions, its concentration in the atmosphere rises, aggravating the greenhouse effect and leading to detrimental effects on the planet’s climate system.

^[1] https://www.britannica.com/science/atmosphere

^[2] https://www.oilsandsmagazine.com/technical/environment/air-emissions

^[3] https://www.researchgate.net/post/How_much_carbon_dioxide_does_it_take_to_increase_Earths_temperature_by_1C_CO2_emissions_affect_Earths_natural_cycle_of_temperatue_change