This Summary for Policymakers (SPM) follows the structure of the Working Group I report. The narrative is supported by a series of overarching highlighted conclusions which, taken together, provide a concise summary. It is virtually certain that globally the troposphere has warmed since the mid-20th century. More complete observations allow greater confidence in estimates of tropospheric temperature changes in the extratropical Northern Hemisphere than elsewhere. There is medium confidence in the rate of warming and its vertical structure in the Northern Hemisphere extra-tropical troposphere and low confidence elsewhere.
Changes in many extreme weather and climate events have been observed since about 1950. It is very likely that the number of cold days and nights has decreased and the number of warm days and nights has increased on the global scale6. It is likely that the frequency of heat waves has increased in large parts of Europe, Asia and Australia. There are likely more land regions where the number of heavy precipitation events has increased than where it has decreased. The frequency or intensity of heavy precipitation events has likely increased in North America and Europe. In other continents, confidence in changes in heavy precipitation events is at most medium.
There is very high confidence that maximum global mean sea level during the last interglacial period (129,000 to 116,000 years ago) was, for several thousand years, at least 5 m higher than present and high confidence that it did not exceed 10 m above present. During the last interglacial period, the Greenland ice sheet very likely contributed between 1.4 and 4.3 m to the higher global mean sea level, implying with medium confidence an additional contribution from the Antarctic ice sheet. This change in sea level occurred in the context of different orbital forcing and with high-latitude surface temperature, averaged over several thousand years, at least 2°C warmer than present (high confidence).
You received this message because you are subscribed to the "USA-Africa Dialogue Series" moderated by Toyin Falola, University of Texas at Austin.
For current archives, visit http://groups.google.com/group/USAAfricaDialogue
For previous archives, visit http://www.utexas.edu/conferences/africa/ads/index.html
To post to this group, send an email to USAAfricaDialogue@googlegroups.com
To unsubscribe from this group, send an email to USAAfricaDialogue-
unsubscribe@googlegroups.com
---
You received this message because you are subscribed to the Google Groups "USA Africa Dialogue Series" group.
To unsubscribe from this group and stop receiving emails from it, send an email to usaafricadialogue+unsubscribe@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.
No comments:
Post a Comment