Global temperature rises to exceed 1.5 Celsius 'within a few years', UNEP says ↧ ↧ Global temperature rises to exceed 1.5 Celsius 'within a few years'... Global temperature rises are set to exceed the key threshold of 1.5 degrees Celsius (2.7 degrees ​Fahrenheit) "within a few years", the UN's environmental body ‌said on Wednesday, creating more extreme weather and intensifying pressure on ecosystems, glaciers and low-lying coastal cities.