In 2015, world leaders committed to keeping the temperature rise to 1.5 degrees in the landmark Paris Agreement, which was seen as crucial to help avoid the most damaging impacts of a changing climate.

While the temperatures recorded last year are being considered as alarming, this initial breach over the span of a 12-month period doesn't significantly disrupt the trajectory set by the landmark Paris Agreement, as the measure is calculated over decades. However, it does signal a concerning step towards potentially surpassing those critical limits in the long term.

The temperature rise can be attributed to a mix of natural and human-driven factors. Human activities like burning coal and greenhouse gas emissions have made the earth warmer. Additionally, a natural climate pattern called El Ni?o has also contributed to the heat.

The 12-month average has been elevated by the hottest January on record, at 1.66 degrees warmer than the average. 

What is the Paris Agreement?

In 2015, world leaders committed to preventing global temperatures from exceeding a 1.5°C increase. The Paris Agreement, a legally binding international treaty on climate change, was unanimously adopted by 196 Parties at the UN Climate Change Conference (COP21) in Paris, France, on December 12, 2015. This historic agreement marked the first time that nearly all nations agreed to reduce greenhouse gas emissions, addressing the root cause of global warming.

Its overarching goal is to hold “the increase in the global average temperature to well below 2°C above pre-industrial levels” and pursue efforts “to limit the temperature increase to 1.5°C above pre-industrial levels."

Why is 1.5 degree threshold important?

The decision to set the 1.5 degrees Celsius limit in the Paris Agreement was based on comprehensive research. Experts found that even a small rise in temperature sustained over several decades, could pose significant risks to certain regions and vulnerable ecosystems.

Setting this limit was viewed as a crucial safeguard against the irreversible consequences from a 1.5 degrees Celsius increase. However, scientists today argue that keeping below the 1.5 degree line is no guarantee of avoiding extreme, global warming effects, as the world is currently experiencing in the form of floods, landslides, drought and forest fires.

What does this temperature rise mean?

The Paris Agreement sets long-term goals, meaning it takes time to determine if they've been met — potentially years or even decades.

While opinions vary on what constitutes exceeding the threshold, consensus among scientists and policymakers is that it must be evaluated based on a multiyear average rather than a single 12-month period.

Although recording temperatures 1.5 degrees higher than average for a year may not breach the Paris Agreement, experts warn that it is indicative of the direction in which we're headed. Scientists have emphasised the critical importance of reducing emissions promptly if we're to adhere to the Paris Agreement's objectives and mitigate the impacts of climate change.

Discussions during COP28

According to the 2023 edition of the Emissions Gap Report, released in the lead up to COP28, it was emphasised that emissions must be reduced by 42 per cent by 2030 to limit warming to 1.5°C above pre-industrial levels.

During COP28, for the first time since the Paris Agreement, an assessment was conducted to evaluate each state's progress towards the agreement's core goal of limiting global temperature rise to 1.5 degrees Celsius above pre-industrial levels.

Discussions at COP28 emphasised the urgent need for revised climate plans to meet their emission targets, especially in the wake of growing gaps in meeting Paris Agreement goals.

In order to maintain the planet's long-term average temperature below the 1.5-degree threshold, the Intergovernmental Panel on Climate Change (IPCC) indicates that the world must achieve net zero emissions by the year 2050.