LONDON (BLOOMBERG, NYTIMES) - Climate scientists warned 2020 could be the world's hottest year on record, with September temperatures eclipsing previous highs and Arctic ice retreating from the seas it usually covers.
Global year-to-date temperatures show little deviation from 2016, the warmest calendar year recorded so far, Europe's Copernicus Climate Change Service reported on Wednesday (Oct 7).
Climate patterns like La Nina in the Pacific Ocean, occurring for the first time in eight years, could determine whether this year turns out to be the warmest on record, according to the researchers.
In September, temperatures reached 0.63 deg C above the 30-year historical average, with the Siberian Arctic and south-eastern Europe in particular feeling the warming effects of climate change.
Arctic sea ice reached its second-lowest extent for September, continuing a fast decline since satellites started monitoring the ice in 1979.
"There was an unusually rapid decline in Arctic sea ice extent during June and July, in the same region where above average temperatures were recorded," Copernicus director Carlo Buontempo said.
"The combination of record temperatures and low Arctic sea ice in 2020 highlight the importance of improved and more comprehensive monitoring in a region warming faster than anywhere else in the world."
This year's record temperatures included an August reading of 54.4 deg C in Death Valley in the United States, possibly the highest ever recorded on earth.
Wildfires have also ravaged Australia and western parts of the US, including California, where land burned has passed a record 1.6 million hectares, the state's fire department said on Sunday (Oct 4).
The National Oceanic and Atmospheric Administration also publishes monthly assessments of global temperature data, which are generally issued about a week after the Copernicus measurements.
The two organisations calculate averages differently, but the results are generally similar.
NOAA relies on surface temperature measurements from land stations, ships and buoys. Copernicus relies heavily on computer modelling.
"Even though the details of the report are different, they all come to the same conclusion that the global temperatures are increasing," said Dr Ahira Sanchez-Lugo, a physical scientist for NOAA's National Centres for Environmental Information.
According to NOAA's predictions, this year is 99.9 per cent certain to be one of the top five hottest years on record. Whether that prediction holds true will partly rely on the impact of La Nina, which NOAA scientists declared last month.
La Nina is the opposite phase of the climate pattern that also brings El Nino and affects weather across the globe. Its strongest influence is usually felt in winter. And while the precise effects are unpredictable, La Nina can result in warmer and drier conditions across the southern US and cooler conditions in south-eastern Alaska, the Northern Plains and western and central Canada.