Oceans. The oceans influence the weather on local to global scales, while changes in climate can fundamentally alter many properties of the oceans. The following five indicators relate to oceans. o Ocean Heat - Three independent analyses show that the amount of heat stored in the ocean has increased substantially since the 1950s. Ocean heat content not only determines sea surface temperature, but also affects sea level and currents. o Sea Surface Temperatures - Sea surface temperature increased over the 20th century and continues to rise. From 1901 through 2015, temperatures rose at an average rate of 0.13°F per decade. o Sea Level - After a period of approximately 2,000 years of little change, global average sea level rose throughout the 20th century, and the rate of change has accelerated in recent years. When averaged over all the world's oceans, absolute sea level increased at an average rate of 0.06 inches per year from 1880 to 2013. Since 1993, however, average sea level has risen at a rate of 0.11 to 0.14 inches per year—roughly twice as fast as the long- term trend. o Coastal Flooding - Flooding is becoming more frequent along the U.S. coastline. Nearly every site measured has experienced an increase in coastal flooding since the 1950s. The rate is accelerating in many locations along the East and Gulf Coasts. o Ocean Acidity - Measurements made over the last few decades have demonstrated that ocean carbon dioxide levels have risen in response to increased carbon dioxide in the atmosphere, leading to an increase in acidity (that is, a decrease in pH). 24 NOAA (National Oceanic and Atmospheric Administration). 2013. State of the climate: Drought: December 2012. Accessed July 2013. xxx.xxxx.xxxx.xxx/xxxx/xxxxxxx/0000/00 Snow and Ice Climate change can dramatically alter the Earth’s snow- and ice-covered areas because snow and ice can easily change between solid and liquid states in response to relatively minor changes in temperature. The following seven indicators relate to snow and ice. o Arctic Sea Ice – September, 2012, had the lowest sea ice extent on record, 49 percent below the 1979-2000 average for that month. The September 2016 sea ice extent was more than 700,000 square miles less than the historical 1981–2010 average for that month—a difference more than two and a half times the size of Texas. March sea ice extent reached the lowest extent on record in 2015 and hit roughly the same low again in 2016—about 7 percent less than the 1981–2010 average. ...
