Our globally changing climate

• Main Authors: Wuebbles, Donald, Easterling, David R., Hayhoe, Katharine, Knutson, Thomas, Kopp, Robert, Kossin, James, Kunkel, Kenneth, LeGrande, Allegra, Mears, Carl, Sweet, William, Taylor, Patrick, Vose, Russell, Wehner, Michael
• Format: Text
• Language: unknown
• Published: DigitalCommons@University of Nebraska - Lincoln 2016
• Subjects: Arctic; Global warming; Ice; permafrost; Sea ice
• Online Access: https://digitalcommons.unl.edu/usdeptcommercepub/592; https://digitalcommons.unl.edu/context/usdeptcommercepub/article/1571/viewcontent/CSSR_2017___01.pdf

1. The global climate continues to change rapidly compared to the pace of the natural variations in climate that have occurred throughout Earth’s history. Trends in globally averaged temperature, sea level rise, upper-ocean heat content, land-based ice melt, Arctic sea ice, depth of seasonal permafrost thaw, and other climate variables provide consistent evidence of a warming planet. These observed trends are robust and have been confirmed by multiple independent research groups around the world. (Very high confidence) 2. The frequency and intensity of extreme heat and heavy precipitation events are increasing in most continental regions of the world (very high confidence). These trends are consistent with expected physical responses to a warming climate. Climate model studies are also consistent with these trends, although models tend to underestimate the observed trends, especially for the increase in extreme precipitation events (very high confidence for temperature, high confidence for extreme precipitation). The frequency and intensity of extreme temperature events are virtually certain to increase in the future as global temperature increases (high confidence). Extreme precipitation events will very likely continue to increase in frequency and intensity throughout most of the world (high confidence). Observed and projected trends for some other types of extreme events, such as floods, droughts, and severe storms, have more variable regional characteristics. 3. Many lines of evidence demonstrate that it is extremely likely that human influence has been the dominant cause of the observed warming since the mid-20th century. Formal detection and attribution studies for the period 1951 to 2010 find that the observed global mean surface temperature warming lies in the middle of the range of likely human contributions to warming over that same period. We find no convincing evidence that natural variability can account for the amount of global warming observed over the industrial era. For the period extending over ...