Explain what would happen to Earth’s climate if there were no greenhouse gases in our atmosphere

Without greenhouse gases in Earth’s atmosphere, the planet's climate would undergo significant changes, leading to drastic cooling and impacting life as we know it. Here's a breakdown of what could happen:

1. Temperature Drop: Greenhouse gases, such as carbon dioxide (CO2) and methane (CH4), trap heat in the atmosphere. Without them, the Earth would lose a critical mechanism for retaining warmth, leading to an average global temperature drop of approximately 33 degrees Celsius (about 59 degrees Fahrenheit). This would result in an average surface temperature of about -18 degrees Celsius (0 degrees Fahrenheit).

2. Increased Temperature Variability: The lack of greenhouse gases would lead to extreme temperature fluctuations between day and night. Without the insulating effect of these gases, nighttime temperatures would plummet significantly, whereas daytime temperatures could rise sharply under sunlight.

3. Impact on Ecosystems: The drastic cooling would create inhospitable conditions for most current ecosystems. Many species would be unable to survive, leading to mass extinctions and a collapse of food chains. The polar regions might become even more inhospitable, while equatorial regions could experience severe droughts or other extreme weather conditions.

4. Glaciation: With lower global temperatures, ice sheets would advance significantly, covering much of the Northern Hemisphere. This glacial expansion would further influence climate patterns, creating a feedback loop that could lead to even lower global temperatures.

5. Ocean Changes: Oceans would cool considerably, affecting marine life and ocean currents. Cold water holds more dissolved gases, which could lead to changes in the chemistry of seawater, impacting marine ecosystems and further affecting biodiversity.

In summary, without greenhouse gases, Earth would experience a severe drop in temperatures, dramatic climate variability, and significant ecological disruption, making the planet largely uninhabitable for most existing life forms.