World on track to exceed 1.5C Global Warming threshold for the first time – Scientists warn

Scientists warn that our warming world is on track to surpass a key temperature limit, marking the first time this threshold will be breached in the next few years.

According to researchers, there is now a 66% probability that the global warming threshold of 1.5 degrees Celsius will be exceeded between now and 2027.

This increased likelihood is attributed to emissions from human activities and anticipated changes in weather patterns during the upcoming summer.

Should the world surpass this limit, scientists emphasize that while concerning, the breach is expected to be temporary.

Reaching the 1.5C mark would signify that the world is 1.5 degrees Celsius warmer than during the second half of the 19th century, before significant industrialization and the subsequent rise in fossil fuel emissions.

The target of 1.5C has become a symbolic goal in global climate change negotiations, with countries pledging to make efforts to limit temperature increases under the 2015 Paris Agreement.

If global temperatures surpass 1.5C consistently for a decade or two, the impacts of warming, such as longer heatwaves, more intense storms, and increased wildfires, would be far more severe.

However, exceeding the threshold in one of the next few years does not mean that the Paris Agreement's limit has been breached. Scientists emphasize that there is still time to mitigate global warming by significantly reducing emissions.

Since 2020, the World Meteorological Organization (WMO) has been providing estimates of the likelihood of surpassing the 1.5C threshold in any given year.

Initially, the WMO predicted a less than 20% chance of exceeding 1.5C in the following five years. By last year, this probability had risen to 50%, and it has now escalated to 66%, which the scientists interpret as “more likely than not.”

What Does Exceeding 1.5C Mean?

The 1.5C figure does not directly measure the world's temperature but serves as an indicator of how much warmer or cooler the Earth has become compared to the long-term global average.

Scientists use average temperature data from the period between 1850 and 1900 as a reference point for the pre-industrial temperature levels before the widespread use of coal, oil, and gas.

Previously, researchers believed that a 2C increase in global temperatures would be the threshold for dangerous impacts. However, in 2018, this estimate was significantly revised, highlighting the catastrophic consequences of surpassing 1.5C.

In 2016, the warmest year on record, global temperatures were already 1.28C above the pre-industrial figure. Researchers now predict with 98% certainty that this record will be broken before 2027.

Furthermore, within the upcoming years, there is a strong likelihood that the 1.5C limit will be surpassed for the first time.

Prof. Adam Scaife, head of long-range forecasts at the Met Office, emphasized the significance of this proximity, stating, “We really are now within reach of a temporary exceedance of 1.5C for the annual mean temperature, and that's the first time in human history we've been that close.”

The researchers emphasize that temperatures would need to remain at or above 1.5C for 20 years to conclude that the threshold specified in the Paris Agreement has been breached.

Nonetheless, even exceeding the limit for just one year is a concerning sign that warming is accelerating and not slowing down.

WMO Secretary-General Prof. Petteri Taalas clarified, “This report does not mean that we will permanently exceed the 1.5C level specified in the Paris Agreement, which refers to long-term warming over many years. However, WMO is sounding the alarm that we will breach the 1.5C level on a temporary basis with increasing frequency.”

Impact of El Niño and Uncertainty

Two crucial factors contribute to the increased likelihood of exceeding the 1.5C threshold.

First, carbon emissions from human activities continue to rise, despite a temporary decrease during the COVID-19 pandemic.

Second, the anticipated occurrence of El Niño, a weather phenomenon with global implications, plays a critical role.

Over the past three years, La Niña events have dampened climate warming to some extent.

However, the additional heat that El Niño brings to the surface of the Pacific is expected to push global temperatures to a new high in the coming year.

There is still uncertainty regarding the onset and magnitude of the El Niño event.

Prof. Scaife explained, “A lot of our forecasts for the El Niño that we think is developing this winter are showing pretty big amplitude. But to actually predict the magnitude of a subsequent event within the five-year period, we can't give the exact dates beyond this one year ahead. So it could be in three or four years from now we get to a two-and-a-half-degree El Niño, and that might be the one that does it.”

Projected Impacts in the UK and Elsewhere

The Arctic is expected to experience more significant warming than many other regions, with temperature anomalies three times higher than the global figure over the next five northern hemisphere winters.

Northern Europe, including the UK, is likely to see increased rainfall during the May to September period over the next five years, as stated in the report.