The increasing amount of carbon dioxide in the air is slowly raising the temperature of the atmosphere, because it absorbs:

Carbon dioxide (CO2) is a critical greenhouse gas that is transparent to incoming short-wave solar radiation but opaque to outgoing long-wave terrestrial radiation [5]. When the Earth's surface is heated by the sun, it re-emits energy in the form of infrared radiation [4]. CO2 molecules are specifically structured to absorb these longer infrared wavelengths, inducing vibrational motions that trap thermal energy within the atmosphere [6]. This process, known as the greenhouse effect, prevents heat from escaping directly into space, thereby raising the atmospheric temperature [2]. While other components like water vapor also absorb infrared radiation, the increasing concentration of CO2 from anthropogenic activities like fossil fuel combustion is the primary driver of modern global warming [5]. In contrast, ultraviolet radiation is primarily absorbed by the ozone layer in the stratosphere, not by CO2 in the lower atmosphere [5].

Sources

1. [1] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 7: Climate Change > 2. greenhouse gases > p. 9
2. [5] https://www.sciencedirect.com/science/article/abs/pii/S004896972403506X
3. [2] Environment and Ecology, Majid Hussain (Access publishing 3rd ed.) > Chapter 6: Environmental Degradation and Management > Greenhouse Effect and Global Warming > p. 7
4. [4] FUNDAMENTALS OF PHYSICAL GEOGRAPHY, Geography Class XI (NCERT 2025 ed.) > Chapter 7: Composition and Structure of Atmosphere > Gases > p. 64
5. [6] https://www.noaa.gov/basics-of-carbon-cycle-and-greenhouse-effect