New global research on temperatures for the past 2000 years indicates the end of last century produced the hottest temperatures for 1400 years.
The study shows that the rise in the average temperatures reverses more than a millennium of gradual cooling.
Victoria University climate scientist James Renwick said the period from the 1970s until 2000 really stood out, as no other similar period was as consistently warm in as many places.
Dr Renwick said the study suggested the rate of warming would continue to increase.
