This year the Earth's climate scored the global warming trifecta: it passed the milestone of 1°C of warming since pre-industrial times; it is set to be the hottest year on record; and it will be the first year in which the concentration of carbon dioxide in the atmosphere is over 400 parts per million (ppm) on average due to the continued burning of fossil fuels.
This is uncharted territory for the Earth. It came as world leaders met in Paris for Climate talks on how to keep warming below 2°C.
The British Met Office has announced the global average temperature in the first nine months of this year was 1.02°C above the estimated level before the industrial age.
Director of the Met Office Hadley Centre Stephen Belcher said: "We have seen a strong El Nino develop in the Tropical Pacific this year and that will have had some impact on this year's global temperature.
"We've had similar natural events in the past, yet this is the first time we're set to reach the 1°C marker and it's clear that it is human influence driving our modern climate into uncharted territory.
“Early indications suggest 2016 will be similarly warm and while it's more difficult to say exactly what will happen in the years immediately after that, we expect warming to continue in the longer term.”
Peter Stott, head of climate monitoring and attribution at the Met Office, said: "This year marks an important first but that doesn't necessarily mean every year from now on will be a degree or more above pre-industrial levels, as natural variability will still play a role in determining the temperature in any given year.
"As the world continues to warm in the coming decades, however, we will see more and more years passing the 1°C marker. Eventually it will become the norm."
Also set to become the norm are figures showing that greenhouse gas concentrations — levels of carbon dioxide, methane and nitrous oxide from industrial, agricultural and domestic activities — have reached 400 ppm.
The World Meteorological Organization (WMO) announced on November 9 that the quantity of carbon dioxide in the air has matched or surpassed 400 ppm for the entire year.
WMO secretary general Michel Jarraud said: “We will soon be living with globally averaged carbon dioxide levels above 400 parts per million as a permanent reality.
“Every year we report a new record in greenhouse gas concentrations. Every year we say that time is running out. We have to act NOW to slash greenhouse gas emissions if we are to have a chance to keep the increase in temperatures to manageable levels.”
Scientists say that cumulative emissions of carbon dioxide will be key to determining eventual global warming. It is estimated that about 2900 Gigatonnes of carbon dioxide (GtCO2) can be emitted to still have any chance of limiting warming to below 2°C.
But, about 2000 GtCO2 has already been emitted, meaning we have used about two-thirds of our 2°C budget. So we are already committed to some level of further warming.