Earth caps off its hottest 12-month period on record, report finds

The planet has capped off its hottest 12-month span on record now that temperatures in the month of October have surpassed previous records throughout history.

Global temperatures have now exceeded 1.3 degrees Celsius of warming since pre-industrial revolution levels, getting dangerously close to the limit of 1.5 degrees Celsius, a goal set forth by the 2015 Paris Agreement, according to a new report by nonprofit Climate Central, which analyzes international climate data.

Mean temperatures over the span of November 2022 to October 2023 exceeded 30-year norms in 170 countries, which exposed 7.8 billion people, or 99% of the global population, to above-average warmth, the report found.

In addition, about 5.8 billion people around the world were exposed to at least 30 days of above-average temperatures, which were found to be made three times more likely from the influence of climate changes, according to the analysis.

Nearly every resident in countries such as Japan, Indonesia, the Philippines, Vietnam, Bangladesh, Iran, Egypt, Ethiopia, Nigeria, Italy, France, Spain, the United Kingdom, Brazil, Mexico and every Caribbean and Central American nation experienced a month-long period of above average temperatures, the researchers said.

The biggest populations affected by this shift in warm temperatures were in India, where 1.2 billion people were affected, and China, where 513 million people were affected.

In the United States, 88 million people, more than a quarter of the country's population, experienced these shifts in number of warm days, according to the report. Houston saw the longest streak of daily temperatures in the 99th percentile at 22 consecutive days in a row between July and August.

New Orleans saw 17 consecutive days of temperatures in the 99th percentile, while Austin saw 16 consecutive days and San Antonio 15 consecutive days, the analysis found.

A warm October helped to tip the planet to its hottest 12-month span on record, according to the report. October 2023 was the warmest October on record, according to a report released Wednesday by Copernicus, Europe's climate change service.

October average sea surface temperatures were the highest on record for a majority of the world’s oceans, according to Copernicus. The month as a whole was about 3.1 degrees Fahrenheit warmer than an estimate of the October average for 1850 to 1900, the designated pre-industrial reference period.

Average surface air temperatures were measured at 59.54 degrees Fahrenheit, and Antarctic sea ice extent remained at record low levels during the month of October, coming in at 11% below average, making the sixth consecutive month of record low levels, the climate change service found.

Experts expect records to continue to be broken in the next 12 months, especially as strengthening El Nino conditions begin to take hold, Andrew Pershing, vice president for science at Climate Central said in a statement.

"This 12-month record is exactly what we expect from a global climate fueled by carbon pollution," Pershing said.

These records will likely be reiterated when the United Nations climate conference -- COP28 -- begins on Nov. 30.