The record-breaking heat wave of 2023 and how climate change is intensifying extreme weather events is surprising many.
The factors contributing to rising temperatures, marine heat waves, and the possibility of setting a new record for the warmest year globally have been unveiled.
The Earth is experiencing an onslaught of heat records, and 2023 is poised to shatter even more.
Last week, the unofficial average temperature of the planet reached unprecedented levels, triggering a cascade of record-breaking daily high temperatures in South Florida, Arizona, and other regions. The scorching trend is expected to persist in the weeks and years to come as climate change continues to reshape global weather patterns, amplifying the intensity of natural events.
According to Robert Rohde, lead scientist for Berkeley Earth, a renowned nonprofit specializing in climate analysis, the next four to six weeks hold a significant possibility of witnessing numerous instances of record-breaking daily highs. The Northern Hemisphere’s summer season exerts a dominant influence on global temperature trends due to its extensive land surface coverage.
The rise in marine heat waves is an alarming consequence of climate change.
In June, these heat waves encompassed 40% of the world’s oceans and seas, but experts predict that the coverage will escalate to 50% as the summer progresses, as stated by the National Oceanographic and Atmospheric Administration (NOAA). Additionally, the Eastern Pacific Ocean is being warmed by El Niño, and this weather phenomenon is projected to intensify and persist until at least the year’s end.
Prominent climate scientist Michael Mann, a professor at the University of Pennsylvania, forewarns that 2023 is highly likely to become the warmest year on record worldwide.
The convergence of various factors, including El Niño and climate change, is anticipated to fuel extreme weather events throughout the summer, such as severe heat waves, droughts, wildfires, and floods.
Berkeley Earth’s analysis, conducted after processing May temperature data, initially assigned a 54% probability to 2023 becoming a record warm year.
With the scorching temperatures witnessed in June, the likelihood of setting a new annual average temperature record has unquestionably increased. Rohde confirms that it is now more probable than not that 2023 will claim the title of the warmest year ever recorded.
The current record for the warmest year stands at 58.69 degrees over global land and ocean, established in 2016 during the last occurrence of El Niño. In comparison, last year’s global average was marginally lower, at 58.44 degrees.
For approximately the past four decades, the average temperature has been derived from a comprehensive dataset encompassing satellite observations, land-based measurements, and atmospheric data, according to Rohde.
To study global average temperatures dating back to the 1970s and earlier, scientists rely on records from weather stations, oceangoing ships, and buoys. This method enables the reconstruction of global temperature trends dating as far back as 1850.
It is through these historical analyses that scientists ascertain that the Earth is currently experiencing its warmest phase since the advent of technology for temperature measurement.
The National Weather Service plays a vital role in collecting data from weather monitoring stations worldwide. This data encompasses records of daily highs and lows, average temperatures, rainfall, snowfall, and maximum wind gusts.
Given the complexity of the data, the National Weather Service subjects information provided by individual stations to quality control routines to identify outliers that appear irrational or inconsistent compared to neighboring stations. Nonetheless, comparing the number of records broken between stations from year to year poses a challenge due to the inherent advantage of older stations established much earlier than those in the late 1800s.
While the identification of maximum and minimum temperatures is straightforward, two additional categories can be perplexing. A cool maximum occurs when the warmest temperature recorded on a specific date is lower than any previous readings. Although rare, these records still occur but with far less frequency than warm records.
On the other hand, a warm low happens when the lowest temperature recorded on a given date is higher than any previous instances of such readings. Warm lows are more frequently observed than cool maximums.
Records can be classified into various types: daily records, monthly and annual records, and all-time records. Daily records pertain to the highest or lowest temperatures, rainfall, or snowfall on any given date. Monthly and annual records encompass the average of highs and lows throughout specific periods.
Finally, all-time records are established when a monitoring station records its highest or lowest temperature, rainfall, or snowfall in recorded history.
These all-encompassing records satisfy the criteria for a daily, monthly, and all-time record.
Although weather records can be compared to a bell curve, with the most commonly observed temperatures clustered in the peak, climate change has shifted this curve to the right. Karin Gleason, chief of the monitoring section at NOAA’s National Centers for Environmental Information, explains that average temperatures have risen, leading to an increased frequency of new warm records being established.
Furthermore, rainfall records are now broken more frequently, especially during high-intensity events.
In many locations, a noticeable upward trend in overnight low temperatures has been documented.
This phenomenon is driven by high humidity and cloud cover, which trap heat and hinder overnight cooling. In fact, warmer overnight lows have begun to push average temperatures higher than the daily highs in several cases.
While the University of Maine’s Climate Reanalyzer reported a new daily global temperature record of 63 degrees, NOAA, the official source of global temperatures and records in the United States, has yet to confirm this announcement.
According to NOAA, the Climate Reanalyzer relies on model output rather than actual temperature measurements and, therefore, cannot serve as a proxy for surface temperatures.
Nevertheless, NOAA acknowledges the influence of climate change and the combined effects of El Niño and hot summer conditions, which have resulted in record-breaking surface temperatures across numerous locations worldwide.
