The year 2025 has landed among the top three warmest years in recorded history, with average surface temperatures reaching approximately 1.44°C above pre-industrial levels. This comes directly on the heels of 2024, which shattered records as the first calendar year to exceed 1.5°C of warming. Carbon Brief’s ongoing “State of the climate” series tracks these numbers in near real-time, and the picture it paints is one of relentless, compounding heat.

Why it matters

For anyone working in carbon dioxide removal, these temperature readings are the scoreboard. They represent the cumulative consequence of every ton of CO₂ that has been emitted and not removed. The fact that 2024 breached 1.5°C for a full year and 2025 is running close behind means the window for CDR to play a meaningful role in bending the curve is not closing in some abstract future. It is closing now. Every fraction of a degree that accumulates makes the scale of removal required larger and the timeline more urgent.

The details

Carbon Brief’s analysis draws on multiple global temperature datasets to produce its rankings and projections. The key numbers tell a stark story:

2024 was confirmed as the hottest year on record, with global surface temperatures exceeding 1.5°C above the 1850-1900 pre-industrial baseline for the first time across a full calendar year. This wasn’t a marginal record. It was a decisive one, fueled in part by a strong El Niño event that amplified underlying warming trends.

2025, even without the same El Niño boost, has tracked remarkably close to 2024’s extraordinary warmth. The first quarter of 2025 recorded the second-warmest start to any year. By midyear, Carbon Brief’s analysis placed 2025 on track to finish as the second or third warmest year on record. The final tally confirms it landed in the top three, with temperatures around 1.44°C above pre-industrial levels.

Ocean heat is a critical part of this story. Carbon Brief highlights surging ocean heat content as a defining feature of the current climate state. The oceans absorb roughly 90% of the excess heat trapped by greenhouse gases, and that thermal reservoir has been hitting record levels. Sea surface temperatures have been running at extraordinary highs since mid-2023, a pattern that has only partially eased.

It’s worth noting that a single year above 1.5°C does not mean the Paris Agreement’s long-term temperature goal has been breached. That target refers to multi-decadal averages, not individual years. But the fact that we’re now routinely flirting with and exceeding 1.5°C in annual readings tells us how little margin remains.

What this changes for CDR

These temperature numbers reshape the CDR conversation in several concrete ways.

First, the math gets harder. Every year of record or near-record warmth that passes without significant net emissions reductions increases the total cumulative CO₂ burden. IPCC scenarios that limit warming to 1.5°C with limited or no overshoot already required billions of tons of CDR per year by mid-century. Continued high emissions push us further into overshoot territory, where CDR isn’t just a complement to emissions cuts but becomes essential for pulling temperatures back down after they’ve exceeded targets.

Second, the urgency argument for CDR investment strengthens. Policymakers and funders who have treated CDR as a distant, nice-to-have technology are running out of room to delay. If we’re already touching 1.5°C in individual years, the deployment timelines for large-scale removal need to compress. That means more funding for direct air capture, enhanced weathering, biochar, ocean-based CDR, and durable biomass approaches today, not in 2035.

Third, the permanence question becomes more pointed. Nature-based carbon sinks, including forests and soils, are themselves under stress from the very warming these reports document. Record heat, drought, and wildfire are degrading the carbon storage capacity of natural systems. This reinforces the case for engineered removal approaches with verifiable, durable storage, even as we continue to protect and restore natural carbon sinks.

Fourth, monitoring and verification matter more than ever. Carbon Brief’s ability to track global temperatures with this precision is a reminder that the CDR field needs equivalent rigor. Buyers, regulators, and the public need to trust that removed carbon is actually removed and stays removed. The stakes are too high for sloppy accounting.

Caveats

A few things this data does not tell us. Annual temperature rankings, while dramatic, are noisy. Natural variability from El Niño, volcanic eruptions, and other factors can shift individual years by a tenth of a degree or more. The long-term trend is what matters most, and that trend is unambiguously upward.

These numbers also don’t tell us whether CDR at scale can actually reverse overshoot. That remains an open and deeply uncertain question. The technology pathways exist in principle, but none have been demonstrated at the gigatonne scale required. And no amount of CDR substitutes for rapid, deep emissions cuts. Removal without reduction is a treadmill that gets steeper every year.

What Carbon Brief’s tracking does provide is an unflinching, data-driven measure of where we stand. For the CDR community, it should function as both motivation and accountability. The atmosphere is keeping score, and right now, we’re losing.

Source: Carbon Brief