Is Climate Change a Natural or Human-Caused Phenomenon?
• Climate varies naturally over both short and long time-scales, but natural climate variability can be distinguished from human-caused climate change. • Scientists have conducted a number of attribution studies that compare observed changes in the global climate with those factors that are known to influence climate. These studies indicate that the climate change observed over the 20th century is due to a combination of changes in solar radiation, volcanic activity, land-use change, and increases in atmospheric greenhouse gases. Of these, greenhouse gases appear to be the dominant driver of climate change over the past few decades.
