UPSC 2025: Consider the following statements: I. Without the atmosphere, temperature would be well below freezing point everywhere on the Earth's surface. II. Heat absorbed and trapped by the atmosphere maintains our planet's average temperature. III. Atmosphere's gases, like carbon dioxide, are particularly good at absorbing and trapping radiation. Which of the statements given above are correct?

Without an atmosphere Earth’s mean surface temperature would be about –18 °C, well below freezing everywhere; the air blanket raises the global average to about +15 °C by absorbing and re-radiating long-wave energy ([en.wikipedia.org](https://en.wikipedia.org/wiki/Illustrative_model_of_greenhouse_effect_on_climate_change?utm_source=openai)). Greenhouse gases such as carbon dioxide are particularly effective at absorbing outgoing infrared radiation and trapping heat ([scied.ucar.edu](https://scied.ucar.edu/learning-zone/how-climate-works/carbon-dioxide-absorbs-and-re-emits-infrared-radiation?utm_source=openai)). Therefore all three statements are correct.