World likely to exhaust carbon budget for 1.5-deg C limit in 3 years: Scientists

New Delhi: If the world continues to release carbon dioxide at the current rate, the carbon budget for limiting global warming to 1.5 degrees Celsius will be exhausted in just over three years, according to an international group of scientists.

The carbon budget refers to the total amount of carbon dioxide the planet can emit while still having a good chance of staying below a certain temperature threshold. In this case, the limit is 1.5 degrees Celsius, which countries agreed to at the Paris climate conference in 2015.

Exceeding the carbon budget does not mean the 1.5-degree limit will be crossed immediately. It means the world is on course to surpass it very soon unless emissions are drastically cut.

The latest "Indicators of Global Climate Change" study, published in the journal Earth System Science Data, also found that the carbon budget for 2 degrees Celsius could be exceeded by 2048 if current levels of CO2 emissions continue.

Scientists said human activities have led to the release of around 53 billion tonnes of carbon dioxide equivalent (Gt CO2e) into the atmosphere every year over the past decade. This is mainly due to increasing emissions from burning fossil fuels and deforestation.

In the last 10 years (2015 to 2024), the Earth's temperature was 1.24 degrees Celsius higher than it was before the industrial era began. Scientists say 1.22 degrees Celsius of this warming was caused by human activities.

The year 2024 was the hottest on record and marked the first calendar year with a global average temperature more than 1.5 degrees Celsius above the 1850–1900 baseline, the period before human activities such as fossil fuel use began significantly affecting the climate.

A permanent breach of the 1.5-degree Celsius target in the Paris Agreement refers to sustained warming over a 20 to 30-year period.

Last month, the World Meteorological Organization said there is a 70 per cent chance that the average global temperature between 2025 and 2029 will exceed pre-industrial levels by more than 1.5 degrees Celsius.

In 2022, the UN Intergovernmental Panel on Climate Change (IPCC) said the world must cut greenhouse gas emissions by 43 per cent by 2030, compared to 2019 levels, to keep the temperature rise within 1.5 degrees Celsius since the Industrial Revolution.

However, IPCC Chair Jim Skea told PTI in an interview in March that the 43 per cent reduction target is now outdated due to a lack of action, meaning the actual reduction needed is even higher.