A new scientific analysis has revealed that the world may have just two years left in its carbon budget if we hope to limit global warming to 1.5°C.
The findings, published by a group of 60 leading climate scientists in Earth System Science Data (2025), a peer-reviewed journal that tracks core climate indicators annually, show how rapidly we’re using up the planet’s remaining allowance for carbon emissions—and how vital it is to act now.
What Is the Carbon Budget?
The carbon budget refers to the total amount of CO₂ we can emit globally while still having a 66% chance of limiting global temperature rise to 1.5°C above pre-industrial levels—a key target of the Paris Agreement.
As of 2025, that remaining budget stands at just 80 billion tonnes of CO₂. At today’s global emissions rates, that would be used up within two years.
While we already saw a 1.5°C global temperature average in 2024, according to Copernicus Climate Change Service, the Paris threshold is based on a multi-year average. Breaching the carbon budget doesn't mean we've technically crossed the line—yet—but it does mean we’re locking ourselves onto a path where that outcome becomes increasingly inevitable.
Why the 1.5°C Limit Matters
The 1.5°C threshold isn’t arbitrary. It marks a critical point beyond which the risks from climate change—extreme weather, droughts, sea level rise, and ecosystem collapse—intensify significantly.
Exceeding it permanently would also require future generations to remove large amounts of CO₂ from the atmosphere to restore a safer climate. That’s a costly and uncertain prospect.
The latest analysis also highlights that every fraction of a degree matters. For example, staying under 1.7°C—a less ambitious but more achievable target—would give us a budget of about 390 billion tonnes, or roughly nine years at current emissions levels.
The Climate System Is Responding Fast
According to the Global Carbon Project, emissions hit a record high in 2024, fuelled by rising global energy demand and continued fossil fuel use.
At the same time, the Earth’s energy imbalance—the amount of extra heat trapped by greenhouse gases—has increased by 25% in the last decade. That means more heat absorbed by the oceans, stronger weather extremes, and faster melting of glaciers and ice sheets.
In fact, global sea level rise has now doubled compared to the long-term average between 1971 and 2018, rising to 4mm per year. Coastal regions are already feeling the effects, and further warming could lead to “catastrophic inland migration,” according to a study published in Nature in May 2025.
This Is Not a Time for Despair — But for Decisive Action
As Professor Joeri Rogelj of Imperial College London puts it:
“The best time to act was decades ago. The second-best time is now.”
While limiting warming to 1.5°C is slipping out of reach, the good news is that every bit of warming we can avoid makes a difference—especially for the most vulnerable communities.
And the solutions? They’re already here.
At a systemic level, countries must follow through on their climate pledges—particularly at the upcoming COP30 summit in November 2025. But local and personal action matters too.
What You Can Do
For Businesses
Companies, large and small, are increasingly expected to show climate leadership — not just through promises, but through measurable action:
- Measure and understand your operational emissions
- Switch to low-carbon suppliers and renewable energy sources
- Reassess business travel policies and logistics
- Support credible emissions reduction or offset programmes
- Communicate progress clearly with employees, customers, and stakeholders
- Build sustainability into long-term planning and decision-making
For Individuals
Even small shifts in daily habits can make a meaningful difference when adopted widely:
- Choose renewable energy for your home where possible
- Reduce unnecessary car journeys and consider lower-carbon travel
- Cut back on food waste and high-emission foods
- Rethink consumption — buy less, repair more, and recycle properly
- Support nature-based climate solutions or offset remaining emissions
- Stay informed and engage with climate-positive initiatives in your community
No one can solve this alone — but every effort helps. And when personal and business action align with broader systemic change, the impact is far greater.
Moving Forward
This latest warning isn’t a reason to give up. It’s a call to move with urgency, purpose, and clarity.
By making informed choices, supporting policy change, and working together across borders and sectors, we still have the power to protect what we love and build a more resilient, liveable future.
