There are two major effects of global warming:
Increasing global temperatures are the primary effects of global warming. However they are causing a broad range of additional, secondary effects :
Changes in temperature and precipitation patterns have also global effects on extreme weather events: They increase the frequency, duration, and intensity of floods, droughts, heat waves, and tornadoes. Other effects of global warming include higher or lower agricultural yields, further glacial retreat, reduced summer stream flows, species extinctions. As further effects of global warming, diseases like malaria are returning into areas where they have been extinguished earlier.
Glacier retreat of Muir glacier: Comparison photos of Muir and Riggs Glaciers in Glacier Bay National Park and Preserve, Alaska. Muir glacier, parts of which were greater than 65 meters thick in 1941, has retreated out of the image in 2004 (towards the upper left) as an effect of global warming. The distance to the visible Riggs glacier in 2004 is ~3 km. During this time, the Muir Glacier retreated more than 20 km (Picture from global warming art http://www.globalwarmingart.com/wiki/Image:Muir_Glacier_jpg).
Even if the global warming effects would convince mankind to stop emitting greenhouse gases, the global warming is expected to continue past 2100 because carbon dioxide (CO2) has an estimated atmospheric lifetime of 50 to 200 years. See also the summary of the predictions for the future increase in temperature up to 2100.
The above text about effects of global warming has been originally taken from Wikipedia.org and then adapted accordingly.