US agencies say 2015 hottest year on record globally

Last year's global average temperature was the hottest ever by the widest margin on record, two US government agencies said.

Data from US space agency NASA and the National Oceanic and Atmospheric Administration showed that in 2015, the average temperature across global land and ocean surfaces was 0.90C (1.62F) above the 20th century average.

Temperatures in 2015 surpassed 2014's previous record by 0.16C (0.29F).

This was the fourth time a global temperature record has been set this century, the agencies said in a summary of their annual report.

"2015 was remarkable even in the context of the larger, long-term warming trend," said Gavin Schmidt, director of NASA's Goddard Institute for Space Studies.

The sharp increase in 2015 was driven in part by El Niño, a natural weather cycle in the Pacific that warms the ocean surface every two to seven years.

But scientists say human activities - notably burning fossil fuels - were the main driver behind the rise.

"We would not have seen the record warming without the long-term trend," Mr Schmidt said.

The latest El Niño started in late 2015 and will last until spring 2016.

It is among the strongest ever recorded but Mr Schmidt and others say the weather phenomenon played just a supporting role in the earth's temperature rise...
 rte.ie