•Temperature:

• –Globally averaged surface temperature is projected to increase by 1.4 to 5.8 ºC over the period 1990-2100.
• –Greater relative warming in the higher latitudes
• –Land areas will warm more and faster than ocean areas
• –“The projected rate of warming is much larger than the observed changes during the 20th century and is very likely to be without precedent during at least the last 10,000 years, based on palaeoclimate data”.

•Precipitation:

• –Globally averaged water vapor, evaporation and precipitation are projected to increase.

–NOTE: At the regional scale, increases and decreases will be observed.

•Extreme Weather:

• –More hot days and heat waves are likely over nearly all land areas
• –Frost days and cold waves are very likely to become fewer
• –Frequency of extreme precipitation events is projected to increase
• –General drying (increased drought frequency) of all mid-continental areas during summer.

• –Glaciers and ice caps will continue their widespread retreat during the 21st century and NH snow cover and sea ice are projected to decrease further.
• –NOTE:  The Antarctic ice sheet is likely to gain mass because of greater precipitation