Global warming is accelerating at an alarming rate, with 2023 poised to become the hottest year on record, according to a recent analysis by the BBC.

In 2023, one-third of days witnessed the average global temperature exceeding 1.5 degrees Celsius above pre-industrial levels. Staying below the 1.5-degree Celsius threshold is required to avoid the impact of climate change, including rising sea levels, extreme weather events, and the destruction of ecosystems.

Dr Melissa Lazenby from the University of Sussex warns that this trend indicates unprecedented temperature levels.

This year’s heatwave follows record-high temperatures experienced in September and a summer marked by extreme weather events worldwide, from wildfires to heatwaves and floods.

These occurrences underscore the immediacy of the climate crisis.

The Paris Agreement, signed by world leaders in December 2015, set the goal of limiting the long-term rise in global temperatures this century to “well below” 2 degrees Celsius, with a striving target of staying under 1.5 degrees Celsius. These limits are measured as the difference between current global average temperatures and those in the pre-industrial period, specifically between 1850 and 1900, before widespread fossil fuel use.

Breaching these Paris Agreement thresholds doesn’t entail exceeding them for just a day or a week. Instead, it involves consistently surpassing them over a 20 to 30-year average. Currently, the long-term average warming figure stands between 1.1 degrees Celsius to 1.2 degrees Celsius, dangerously close to the 1.5-degree threshold.

The first time the modern era saw the 1.5 degrees Celsius threshold breached was for a few days in December 2015, coinciding with the signing of the Paris Agreement. Since then, this limit has been repeatedly exceeded, typically for short periods. A particularly strong El Niño event contributed to approximately 75 days above the 1.5 degrees Celsius mark in 2016.

However, by 2 October, data from the Copernicus Climate Change Service indicates that there have been around 86 days in 2023 when temperatures have exceeded 1.5 degrees Celsius above the pre-industrial average. This surpasses the 2016 record well before the year’s end, indicating an acceleration in global warming.

Dr Melissa Lazenby expressed concern about the fact that the 1.5 degrees Celsius anomaly is now being reached daily and for an extended period.

One significant factor contributing to these temperature anomalies is the onset of El Niño conditions, which were confirmed a few months ago, although they are currently weaker than their peak in 2016. El Niño conditions are responsible for transferring heat from the eastern Pacific Ocean into the atmosphere. In conjunction with long-term warming from fossil fuel combustion, this phenomenon may explain why 2023 is the first year in which the 1.5 degrees Celsius anomaly has been recorded between June and October.

Professor Ed Hawkins from the University of Reading highlighted the unusual nature of the current situation, with the 1.5 degrees Celsius anomaly occurring during the northern hemisphere summer, a departure from historical patterns.

In the context of El Niño and La Niña, temperatures are considered to be in these conditions when they deviate by 0.5 degrees Celsius above or below the average. Recent data indicates that El Niño conditions are strengthening, a development that could further contribute to the ongoing rise in global temperatures and extreme weather events.

September of this year saw some temperature extremes, with certain days experiencing differences exceeding 1.5 degrees Celsius above the pre-industrial average. On some days, this deviation even surpassed 1.8 degrees Celsius.

For the entire September, the global average temperature was approximately 1.75 degrees Celsius above the pre-industrial level.

Year-to-date data indicates that the global average temperature in 2023 is roughly 1.4 degrees Celsius above the average for the period between 1850 and 1900, according to the Copernicus Climate Change Service.

Another development is the unusually high temperatures observed in the world’s oceans this year. These elevated ocean temperatures contribute to the release of additional heat into the atmosphere. The North Atlantic Ocean is currently experiencing its highest recorded temperatures, and in the North Pacific Ocean, an area of abnormally warm water stretches from Japan to California.

Dr Jennifer Francis from the Woodwell Climate Research Centre in the US points out the significance of this ocean warming trend. While greenhouse gas emissions are a major contributor to rising average temperatures, the exact reasons behind the surge in sea temperatures are not entirely understood.

One theory suggests that a reduction in air pollution from shipping activities in the North Atlantic may have played a role. This reduction in small particles, known as “aerosols,” could have contributed to increased warming, highlighting the complex and interconnected nature of climate systems.

Aerosols, which had previously partially countered the effects of greenhouse gas emissions by reflecting some of the sun’s energy, played a role in keeping the Earth’s surface cooler than it would have been otherwise. Their reduction in the atmosphere due to decreased shipping emissions may have contributed to increased warming.

Another significant factor impacting global temperature anomalies is the situation around Antarctica. Data indicate sea ice levels are significantly below those observed in previous winters. Some experts suggest that two temperature spikes in recent months in Antarctica, have played a role in elevating the global average temperature.