The Earth’s average surface temperature in 2015 was the warmest since records began in the 19th Century, according to NASA and the National Oceanic and Atmospheric Administration (NOAA).
The pair of American scientific agencies issued the warning on Wednesday, noting that the increase is part of a long-term warming trend, with 15 of the 16 warmest years on record having occurred since the turn of the millennium.
This past year beat 2014 by 0.13°C, a major jump on the 2013-2014 increase. The only other time such a year-on-year spike in temperature has been seen was in 1998.
The announcement is the product of two separate analyses of NASA data, one by the space agency and the other by NOAA. The data comes from surface temperature observations from some 6,300 weather stations, buoys and ships around the world, as well as from research outposts in Antarctica. NASA researchers then use an algorithm to take into account urban heating effects and spacing of the different stations, which could adulterate the data.
The NASA and NOAA communiqué comes two days after the publication of research in the journal Nature Climate Change that found that the amount of heat being trapped in the world’s oceans is accelerating.
From 1865 to 1997, the world’s oceans absorbed roughly 150 zettajoules of heat energy. Then from 1997 to 2015, another 150 zettajoules were absorbed. One zettajoule is a titanic volume of energy. To put this in context, it would take two years’ worth current annual global energy consumption to make up one zettajoule. But it is not the amount so much as the acceleration in the last couple of decades that alarms the researchers.
This study depends upon data from ocean-going vessels dating back to the 1870s but also modern underwater monitors and computer modelling.
The researchers say that such warming has significant consequences for life in the oceans and on food from the oceans that humans gather, as well as on patterns of ocean circulation, where storms go and how intense they will be. Warming causes thermal expansion, contributing to sea-level rise, which in turn inundates coastal wetlands, erodes beaches, heightens the risk of flooding, and increases the salinity of estuaries and aquifers. This puts coastal communities at risk, hikes up infrastructure costs and also itself contributes to the overall global warming trend because the warmer that oceans get, the less able they are to absorb heat, making temperatures rise on the land and in the atmosphere.
A by-product of this global warming may be the vast 1000-kilometre-wide patch of unusually warm waters in the Pacific off the BC coast stretching from Mexico to Alaska, according to researchers, although the full set of causes remains unknown. First detected in 2013 by University of Washington climate scientists, the “blob” as researchers call it, has been tracked ever since. With an average temperature some 2°C warmer than normal, the anomaly felt nice and cosy for tropical fish such as butterfish, tope sharks and ocean sunfish, who have been spotted making their way to the BC coast, but the blob also retarded nutrient growth, hurting salmon populations.
Only in the past week has University of Victoria oceanographer Richard Dewey noticed that the long-lived blob has begun to dissipate as strong cold winds from Alaska that have been absent in recent years have finally begun to show up again. Researchers are still trying to understand the reasons for this, although they suspect that major changes in the Arctic due to warming are responsible here as well.
Dewey told the CBC that regional ecosystems will rebound, but it may take up to three years for salmon runs to restore themselves to levels that existed prior to the arrival of the blob.
The Climate Examiner speaks to BC-based Carbon Engineering about the technology, the business and the policies that could make direct air capture, synfuels and carbon sequestration work.