Sunlight

• Sunlight is a portion of the electromagnetic radiation given off by the Sun.
• Sunlight consists of 55% Infrared light (above 700nm), 42% Visible light (400 to 700nm) and 3% Ultraviolet light (below 400nm).
• Total energy of sunlight depends on the distance to the Sun and thus on the time of year.
• The Sun is about 5,500 °C.
• Ultraviolet C (UVC) has germicidal properties.
• Ultraviolet B (UVB) damages DNA and causes sunburn.
• Ultraviolet A (UVA) is less damaging to DNA and is used in cosmetic sun tanning.
• Visible light ranges from 380-700nm.
• Infrared light ranges from 700-1,000,000 nm (1 mm).
• Every 11 years, the Sun's magnetic field completely flips, this is the solar cycle.
• Solar flares and coronal mass ejections increase during the solar cycle.
• Weather includes sunshine, rain, cloud cover, winds, hail, snow, freezing rain, flooding, blizzards, ice storms, thunderstorms, excessive heat, heat waves etc.
• Climate is the behavior of the atmosphere over long periods of time.
• Climate change is the change in long-term averages of daily weather.
• Global warming is the long-term heating of Earth's surface observed since the pre-industrial period (between 1850 and 1900) due to human activities, primarily fossil fuel burning.
• Earth's surface temperature has risen by 1 degree Fahrenheit in the past century.
• The greenhouse effect occurs when greenhouse gases in the atmosphere trap some of the heat radiated from the earth surface.
• Human activities have altered the chemical composition of the atmosphere through the buildup of greenhouse gases: primarily carbon dioxide, methane, and nitrous oxide.
• Carbon dioxide's warming effect helps stabilize Earth's atmosphere.
• Without carbon dioxide, Earth's surface would be some 33°C (59°F) cooler.
• The level of carbon dioxide in Earth’s atmosphere has been rising consistently for decades and traps extra heat near Earth's surface, causing temperatures to rise.
• The greenhouse effect retains heat by restricting the flow of radiation through the air and into space.
• A greenhouse gas (GHG) is a gas capable of trapping heat by impeding the flow of infrared thermal radiation out of a planet's atmosphere.
• CO2 concentration increased from 312 parts per million (ppm) in 1960, to 412 ppm in 2023.
• An ice age is a long period of reduction in the temperature of the Earth's surface and atmosphere.
• There have been five major ice ages in the history of Earth over the past 3 billion years: 2.4 billion years ago; 850million years ago; 460 mya; 360 mya; 2.6 mya.
• Within ice ages, there exist periods of severe glacial conditions and warmer conditions, referred to as glacial periods and interglacial periods.
• The Earth is currently in such an interglacial period, with the last glacial period ended approximately 11,700 years ago.