The concentration of CO₂ in the atmosphere has reached 429 ppm, an all-time high in three million years. This alarming rise, despite the temporary dip in 2020, places companies at the center of major CSR challenges and redefines decarbonization strategies. As highlighted by Futura Sciences, this level continued to climb, reaching 433.24 ppm on April 5, 2026
Global CO₂ in the Air: A New Absolute Record
The concentration of CO₂ in Earth’s atmosphere has just crossed an unprecedented threshold in three million years. According to the latest measurements from the Mauna Loa Observatory, the atmospheric carbon dioxide level exceeded the symbolic barrier of 429 parts per million (ppm) in March 2026, signaling a meteoric rise in this major atmospheric pollutant. As noted by Futura Sciences, this level continued to rise, reaching 433.24 ppm on April 5, 2026
A Record That Shatters 2019
In 2019, the CO₂ concentration had already crossed a critical threshold, peaking at 415 ppm, establishing a new historic record that stunned the scientific community. However, the 429.35 ppm recently recorded marks a staggering rise of more than 14 ppm in just seven years.
To grasp the scale of this change, recall that in 1960, atmospheric CO₂ hovered around 320 ppm. The current rise represents a dizzying 49% increase relative to preindustrial levels of 1850, according to NASA data.
The 2020 Exception: a Brief but Revealing Interlude
The year 2020 offered a brief pause in this relentless ascent. The lockdown measures tied to the COVID-19 pandemic triggered a temporary drop in global greenhouse gas emissions. The drastic halt of air, ground transport, and industrial activity led to a temporary 7% dip in global emissions.
This reduction, however, proved inconsequential in the face of the scale of the challenge. Jean-Baptiste Renard, a researcher at the Laboratory of Environmental Physics and Chemistry, illuminated this hard truth: « Unlike fine particulate emissions, for example, CO₂ pollution is global and drives climate warming. The sources are multiple and not localized; it is difficult to neutralize them all. » By 2021, emissions rebounded with particular vigor, largely offsetting the temporary dip and fueling the inexorable rise in atmospheric concentrations.
Systemic Consequences for the Planet’s Balance
These CO₂ levels push the Earth into a climate regime not seen since the Pliocene, three million years ago. At that distant time, global temperatures ran 3 to 4°C higher than today, while ocean levels stood 15 to 20 meters above present measurements. Lush forests thrived in Antarctica, illustrating a radically different climate balance, as National Geographic notes.
Martin Siegert, a professor of geoscience at Imperial College London, emphasizes the urgent nature of the situation: “If humanity cannot remove CO₂ from the atmosphere at scale, major impacts are inevitable, sooner or later.” Scientific projections point to astonishing CO₂ concentrations of around 2,000 ppm by the mid-23rd century if current trends persist.
Toward Stronger Climate Governance
In response to this climate emergency, monitoring initiatives are multiplying with unprecedented precision. The UN has recently published a list of the 50 human-caused methane-emitting sites, according to Le Figaro, revealing a Chilean landfill at the top with more than 100,000 tonnes of annual emissions.
These satellite monitoring systems now offer real-time identification of major emission sources, giving businesses and governments tools to steer with surgical precision. The UN’s MARS (Methane Alert and Response System) program has already helped curb emissions from 41 major sources, representing 1.2 million tonnes of methane.
The Mauna Loa Observatory continues to document this alarming progression of atmospheric CO₂ with metronomic regularity. According to recent data compiled by Yahoo News, the global temperature in 2024 exceeded preindustrial levels by 1.55°C, briefly crossing the critical 1.5°C threshold set by international agreements.
