Although air temperature will cross over into a new normal of extremes in only a few decades, ocean surface temperature will cross over soon as well (see map above). Alarmingly, ocean pH already crossed over in 2008, both because pH has varied extremely little, historically and the oceans are absorbing a large percentage of man-made CO2 emissions, which turns the water more acidic.
Departure date for ocean pH
The level of data generated by the study is substantial. One map specifies when local temperature will depart for various cities around the world, and it reflects the early extremes in the tropics. For example, the departure date is 2029 in Jakarta and Lagos, 2031 in Mexico City, 2047 in New York City, 2066 in Reykjavik and 2071 in Anchorage.
Another map posted on Mora’s lab page allows the reader to pick any one of 10,000 spots on the planet (Chicago, New Delhi, the South Pacific) and see the entire air temperature curve from 1860 to 2013, its projection to 2100 and the date at which climate departure will occur. The paper, data and graphs can be downloaded from the lab page, too.
Maps reprinted with permission from Nature and Camilo Mora.