Solar radiation is primarily responsible for heating both the Earth's surface and the lower atmosphere. The Sun emits electromagnetic radiation, including visible light and a portion of ultraviolet and infrared radiation. When this solar radiation reaches the Earth's surface, it is absorbed and heats the land, water, and other surfaces. These heated surfaces then radiate heat energy back into the atmosphere as infrared radiation.

Regarding your second question, Earth's atmosphere does not block all radiation, but it does interact with and absorb certain wavelengths of radiation.

Here's a breakdown:

In summary, solar radiation from the Sun is the primary source of energy that heats the Earth's surface and lower atmosphere. The Earth's atmosphere does interact with radiation, both absorbing and transmitting different wavelengths. Greenhouse gases in the atmosphere play a key role in trapping some of the Earth's heat energy through the greenhouse effect, contributing to the overall warming of the lower atmosphere.

Dr Gaurav H Tandon thank you for your contribution to the discussion

No, Sun can influence Earth's climate, but it isn't responsible for the warming trend we've seen over recent decades. The Sun is a giver of life; it helps keep the planet warm enough for us to survive. We know subtle changes in Earth's orbit around the Sun are responsible for the comings and goings of the ice ages. Most of Earth's energy comes from the Sun. Shortwave solar radiation that's absorbed by Earth's surface or atmosphere is re-radiated it as long wave, infrared radiation, also known as heat. The more solar radiation is absorbed, the more heat is re-radiated and the temperature of the atmosphere goes up. The Sun's radiation strikes the Earth's surface, thus warming it. As the surface's temperature rises due to conduction, heat energy is released into the atmosphere, forming a bubble of air that is warmer than the surrounding air. The heat source for our planet is the sun. Energy from the sun is transferred through space and through the earth's atmosphere to the earth's surface. Since this energy warms the earth's surface and atmosphere, some of it is or becomes heat energy.The atmosphere is mainly heated by the long-wave terrestrial radiation. The solar radiation heats the surface of the land. As a result, this heat is carried as convection currents to the higher realms of the atmosphere. Earth returns an equal amount of energy back to space by reflecting some incoming light and by radiating heat. Earth's magnetic shield protects us from the cosmic radiation and is strongest at the equator and weakest near the poles. The magnetic shield diverts most of the radiation around the earth. Earth's atmosphere shields us from most of the remaining radiation that travels to Earth. The atmosphere and the surface of the Earth together absorb 71 percent of incoming solar radiation, so together; they must radiate that much energy back to space for the planet's average temperature to remain stable. While an underground shelter covered by 1 meter (3 feet) or more of earth provides the best protection against fallout radiation, the following unoccupied structures (in order listed) offer the next best protection: Caves and tunnels covered by more than 1 meter (3 feet) of earth. Microwaves have a long wavelength, though not as long as radio waves. The Earth's atmosphere is transparent to some wavelengths of microwave radiation, but not to others. The longer wavelengths (waves more similar to radio waves) pass through the Earth's atmosphere more easily than the shorter wavelength microwaves.