Global average temperatures in 2015 are likely to be the warmest on record, and may reach the symbolic and significant milestone of 1ø Celsius above the pre-industrial era. This is due to a combination of a strong El Ni¤o and human-induced global warming, according to the World Meteorological Organization (WMO). The years 2011-2015 have been the warmest five-year period on record, with many extr