Vital Signs of the Planet | Why have global warming
TakeawaysThegreenhouseeffectisessentialtolifeonEarth,buthuman-madeemissionsintheatmospherearetrappingandslowingheatlosstospace. FivekeygreenhousegasesareCO2,nitrousoxide,methane,chlorofluorocarbons,andwatervapor. WhiletheSunhasplayedaroleinpastclimatechanges,theevidenceshowsthecurrentwarmingcannotbeexplainedbytheSun. TheGreenhouseEffectIncreasingGreenhousesGasesAreWarmingthePlanetScientistsattributetheglobalwarmingtrendobservedsincethemid-20thcenturytothehumanexpansionofthe"green...
Takeaways The greenhouse effect is essential to life on Earth, but human-made emissions in the atmosphere are trapping and slowing heat loss to space. Five key greenhouse gases are CO2, nitrous oxide, methane, chlorofluorocarbons, and water vapor. While the Sun has played a role in past climate changes, the evidence shows the current warming cannot be explained by the Sun. The Greenhouse Effect Increasing Greenhouses Gases Are Warming the PlanetScientists attribute the global warming trend observed since the mid-20th century to the human expansion of the "greenhouse effect" — warming that results when the atmosphere traps heat radiating from Earth toward space.
Life on Earth depends on energy coming from the Sun. About half the light energy reaching Earths atmosphere passes through the air and clouds to the surface, where it is absorbed and radiated in the form of infrared heat. About 90% of this heat is then absorbed by greenhouse gases and ...