• 2015 global temperature anomalies, January-October. (Map: World Meteorological Organization)

The World Meteorological Organization has declared that 2015 is likely to be the warmest year on record — and it’s not even over yet.

In a report issued Wednesday — just days before the start of the UN Climate Change Conference in Paris — the WMO said the combination of a strong El Niño pattern in the Pacific Ocean and human-caused global warming is likely to result in the warmest global average surface temperature ever recorded.

Preliminary data from January to October shows that the global average surface temperature in 2015 was around .73 C above the late 20th-century (1961-1990) average, and about 1C above the pre-industrial (1880-1899) average. The latter is a troubling and symbolic milestone; experts believe 2 C of warming is the absolute most Earth can tolerate without risking catastrophic changes to food production, wildlife and sea levels.

While there is still two months’ worth of data to be collected and factored into the 2015 averages, global trends and a still-strengthening El Niño mean this year will likely represent a turning point in global climate change.

Global annual average temperatures anomalies (relative to 1961-1990) based on an average of three global temperature data sets from 1950 to 2014. The 2015 average is based on data from January to October. Bars are coloured according to whether the year was classified as an El Niño year (red), a La Niña year (blue) or an ENSO-neutral year (grey). (Chart: World Meteorological Organization)

The WMO’s report is expected to be a major point of discussion at next week’s climate conference, where world leaders will debate how to ensure global temperature rise does not cross the 2 C threshold.

“Greenhouse gas emissions, which are causing climate change, can be controlled,” said WMO Secretary-General Michel Jarraud. “We have the knowledge and the tools to act. We have a choice. Future generations will not."

Read the WMO’s full report here.