Climate change

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Climate change is a sustained alteration in the average state, variability, or extremes of the climate system. Geological records show that climate has changed repeatedly over Earth's history on timescales from years to hundreds of millions of years.

Natural causes include volcanic activity, changes in greenhouse gases, continental drift, mountain building, ocean circulation, solar variation, asteroid impacts, and changes in Earth's orbit and axial orientation.

Evidence for ancient climates comes from rocks, fossils, sediments, ice cores, pollen, tree rings, isotope ratios, and glacial landforms. These records reveal ice ages, greenhouse intervals, abrupt events, and recurring orbital influences.

Modern warming is dominated by human greenhouse-gas emissions. It is superimposed on natural variability and is changing temperature, rainfall, oceans, ice, sea level, ecosystems, and the rates of many geological and biological processes.

Source details and credits

• Source / publisher: Wikipedia
• URL type: WWW
• Credits: Wikipedia
• URL: https://en.wikipedia.org/wiki/Climate_change_(general_concept)