Our chance of keeping global warming to 1,5°C is moving away

Keeping global warming below 1,5°C under the Paris Agreement will be vital for biodiversity and human health, but unless greenhouse gas emissions are reduced dramatically and rapidly, we only have a 50% chance. possibilities of achieving it by 2030, warned scientists from Imperial College London.

The Paris Agreement aims to limit global temperature rise to less than 2°C above pre-industrial levels, but we are rapidly depleting the existing global carbon budget, leaving us with less than 250 gigatonnes of CO2. This makes it difficult to achieve the objective of the agreement.

Scientists warn that if global carbon dioxide emissions remain at around 40 gigatonnes as in 2022, the planet's carbon reserves will be depleted by 2029 with a temperature increase of 1,5° C.

Meanwhile, the amount of carbon that gives us a 50% chance of limiting global warming to 2°C is about 1.200 gigatonnes. This means that if carbon dioxide emissions remain at current levels, the 2°C budget will be exhausted in 2046.

We are close to the end of the carbon budget

This means the budget is smaller than previously estimated and has been halved since 2020."due to the continued increase in global greenhouse gas emissions, mainly caused by the burning of fossil fuels, as well as a better estimate of the cooling effect of aerosols, which are decreasing globally due to measures to improve the air quality and reduce emissions"they explain in a study published in the Nature magazine.

Robin Lamboll, a researcher at the Center for Environmental Policy at Imperial College London, said: "Our finding confirms what we already know: we are not doing enough to keep global warming below 1,5°C".

"The current budget balance is so small that minor changes in our understanding of the world can lead to large proportional changes in the budget. However, estimates indicate that emissions will remain at current levels for less than ten years."Lamboll explains."The lack of progress on reducing emissions means we are increasingly confident that the window of opportunity to keep warming at safe levels is rapidly closing.".

The tough and forceful update to the global carbon budget is in line with the latest UN Climate Report 2021, which notes that the remaining carbon budget with 1,5°C warming is meager and capacity is 1/3 of the expected. Joeri Rogel, director of research at the Grantham Institute at Imperial College London, said: ““This shows the importance of not only looking at the underlying estimates but also taking into account the uncertainty associated with them.”

Better calculate remaining carbon to avoid global warming

Calculating remaining carbon can be complicated because you have to take into account a number of variables, including warming caused by gases other than carbon dioxide.

The new study "includes an updated data set and improved climate models compared to other recent estimates, characterizing these uncertainties and increasing confidence", the researchers note, in the remaining carbon estimates.

"Improved method also provides new insights into the importance of potential climate system responses to net zero""Net zero means achieving an overall balance between global emissions produced and emissions removed from the atmosphere"they added.

Still, uncertainty remains about how the global climate system will respond in the years before reaching net zero. “The climate is likely to continue warming due to impacts such as melting ice, the release of methane and changes in ocean currents”, They explain.

"However, carbon sinks, such as increased vegetation growth, can also sequester large amounts of carbon dioxide, causing global temperatures to drop before reaching zero.Still, the study highlights the urgent need to reduce emissions.

"At this stage we can assume that the opposite heating and cooling will cancel out once we reach zero"Lamboll said."But only as let's reduce emissions and as we get closer to net zero we will be able to see what adjustments in warming and cooling will look like in the long term"added the scientist.

“Every fraction of a degree of warming will make life more difficult for people and ecosystems.” This study is another warning from the scientific community. Now everything depends on governments.


With information of: https://www.sustainability-times.com/