Scientists warn carbon budget for 1.5C exhausts within three years

A peer-reviewed Earth System Science Data study by over 60 scientists found only 130 gigatonnes of CO2 remain in the carbon budget for a 50% chance of staying within 1.5C, exhaustible in three years. The assessment intensifies pressure on Indian companies to align net-zero strategies with accelerating warming evidence.

A peer-reviewed study in the Earth System Science Data journal, led by over 60 climate scientists under the Indicators of Global Climate Change (IGCC) initiative, found only 130 gigatonnes of CO2 remain in the global carbon budget for a 50% chance of staying within 1.5C of warming. At current emissions rates, that budget would be exhausted in just three years. Human-induced warming reached 1.36C above pre-industrial levels in 2024, with a 10-year average of 1.22C, while the rate of warming accelerated to 0.27C per decade, the fastest on record.

The findings affect governments, companies, and vulnerable communities worldwide, as annual greenhouse gas emissions remain at record highs despite net-zero pledges and clean-energy investments. The study warns the difference between 1.5C and 2C is not marginal, with every additional tenth of a degree bringing disproportionate harm including greater crop losses, deadlier heatwaves, more frequent flooding, and worsening impacts for vulnerable communities. Continued emissions growth puts the world on track for 2.5C to 2.9C of warming by century's end, far beyond thresholds considered safe.

Indian companies and policymakers should treat the assessment as evidence to accelerate decarbonisation, as scientists stress every fraction of a degree still matters and action remains possible. The IGCC initiative provides up-to-date indicators between major IPCC reports, the last of which was published in 2021. Corporate sustainability teams should monitor the run-up to COP30 in Brazil, where these data will inform negotiations, and align net-zero strategies and disclosures with the accelerating warming trajectory rather than relying on outdated baselines.

Key figure — Remaining carbon budget: 130 gigatonnes of CO2, exhaustible in three years