melting of ice sheets and retreat of glaciers at unprecedented rates
shifts in the timing of spring events, which are occurring much earlier than previously
shifts in the distribution and abundance of a number of plant and animal species
changes in precipitation patterns on land, with some areas subjected to more severe and frequent droughts, and other areas more frequent and severe floods
all of the above
None of the above. To date, global warming has had no effects on any of the things mentioned above.