A new analysis of the global climate from 2011 to 2015 by the World Meteorological Organization has highlighted the increasing link between human-induced climate change and extreme weather events.
The new report, The Global Climate 2011-2015, investigated the warmest five-year period on record, 2011 to 2015, which was also the warmest on record for every single continent except Africa. These record temperatures were accompanied by rising sea levels, as well as major declines in Arctic sea-ice extent, continental glaciers, and northern hemisphere snow cover. As the World Meteorological Organization (WMO) notes, “All these climate change indicators confirmed the long-term warming trend caused by greenhouse gases.” The WMO also points to the awkwardly historic milestone, which we reported back in June, that carbon dioxide levels surpassed 400 parts per million for the first time in 4 million years.
Of significant importance, the report also examined whether human-induced climate change was directly linked to the increase in the number and intensity of extreme weather events. Specifically, the report found that of the 79 studies published by the Bulletin of the American Meteorological Society between 2011 and 2014, more than half concluded that human-induced climate change contributed to the extreme event tackled in the relevant report.
“The Paris Agreement aims at limiting the global temperature increase to well below 2° Celsius and pursuing efforts towards 1.5° Celsius above pre-industrial levels,” said WMO Secretary-General Petteri Taalas.
“This report confirms that the average temperature in 2015 had already reached the 1°C mark. We just had the hottest five-year period on record, with 2015 claiming the title of hottest individual year. Even that record is likely to be beaten in 2016.
“The effects of climate change have been consistently visible on the global scale since the 1980s: rising global temperature, both over land and in the ocean; sea-level rise; and the widespread melting of ice. It has increased the risks of extreme events such as heatwaves, drought, record rainfall and damaging floods.”
The authors of the report conclude both that human-induced climate change likely increased the likelihood of the number of extreme weather and climate events during the report’s study period, as well as concluding that human-induced climate change increased the probability of extreme high temperatures by a factor of ten or more. Examples of these climate change-induced temperatures are found everywhere: high seasonal and annual temperatures in the United States during 2012 and in Australia in 2013; hot summers in eastern Asia and western Europe in 2013; heatwaves in Australia during the spring and autumn of 2014; record annual warmth in Europe in 2014; and a heatwave in Argentina in December of 2013.