Extract from ABC News
ABC News HomepageClimate records have fallen this year at an alarming rate.
Just this week, Earth broke its record for the warmest day on three occasions and set new July highs for ocean temperatures, while Antarctic sea ice remained at levels well below anything previously seen in the satellite era.
The ongoing warmth is making it increasingly likely that 2023 will become Earth's hottest year on record, as climate change and the ongoing development of El Niño continue to bring abnormally high ocean and air temperatures.
The surface temperature anomaly for July 6 shows parts of Antarctica are about 20 degrees above average for July.
The rise in global air temperature this week compared with previous years has been stark.
According to United States government data, the Earth's highest average temperature on any day was previously 16.92 degrees Celsius.
That was exceeded on four consecutive days this week, peaking at 17.23C on July 6.
The sudden spike is the result of abnormal spells of heat across much of the globe, including daily temperature anomalies up to 20C above average near the coast of Antarctica.
Australia has also played its role in the global record, with minimum temperatures near the east coast climbing as much as 10C above average.
Considering the Earth's average temperature typically peaks in late July in the middle of the northern hemisphere summer, it is highly probable the all-time record will be broken again during coming weeks.
Simmering oceans at record-high levels for four months
The 2023 data from the world's oceans has been even more extreme than that from the atmosphere.
Daily sea surface temperature records have been broken more than 100 days in a row, according to US data.
While it is not uncommon for global records to be broken by a slim margin of 0.1C, the daily figure has been 0.2C to 0.3C above previous records in recent months.
That means in the unlikely event oceans suddenly start cooling, they will still remain at record-high temperatures for at least another few weeks.
Warm oceans leading to record-low Antarctic sea ice
The warm global waters are having a dramatic impact on Antarctic sea ice, which is running at record-low levels and well outside the bounds of typical variability.
The ice deficit, compared to normal, has been growing for months and is now more than 2.5 million square kilometres below average.
That is roughly the size of Western Australia.
Illustrating how unusual the size of the missing ice is, the deficit is more than 1.5 million square kilometres below the previous record for July.
The failure of the Southern Ocean to freeze this year marks a deviation from recent decades.
Antarctic sea ice has not previously seen a significant reduction due to climate change. That's happened in the North Pole.
This leads to a crucial question for scientists. Is the lack of ice a statistical outlier, or the beginning of a more permanent shift in Earth's climate system?
2023 and 2024 increasingly likely to become warmest years on record
With records breaking, it looks increasingly likely that 2023 will become the hottest on record.
After May it was sitting in fourth position, behind 2016, 2017 and 2020, but June was the warmest on record, followed by a record-warm start to July.
While the year began with La Niña, the recent upswing is causing this year's ranking to climb rapidly, a trend expected to continue as the Pacific transitions into El Niño.
During El Niño, the equatorial Pacific is warmer than normal, and this leads to additional heat being shifted from the ocean into the atmosphere.
Based on historical figures of how El Niño years evolve, along with the recent spike in global temperatures, 2023 looks more and more likely to pass 2016 as the Earth's warmest year.
And if historical trends continue, 2024 is likely to be even warmer because the highest temperatures in an El Niño cycle normally arrive in the second year.
This was evident during the last El Niño, which developed in 2015 and delivered a record-warm year in 2016.
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