20th of January: A new day begins

The year 2024 marks another critical juncture in the escalating climate crisis. Official data confirms that global CO2 emissions have reached a new peak, surpassing previous records and continuing a deeply concerning trend. According to the Global Carbon Project's 2024 budget, global carbon dioxide (CO2) emissions are projected to reach approximately 40.9 billion tonnes. This includes 36.6 billion tonnes from fossil sources (coal, oil, and gas) and 4.3 billion tonnes from land-use change (primarily deforestation).

While slightly lower than some earlier projections, this figure still represents a significant increase compared to recent years and reinforces the established upward trajectory of the last decade, with emissions rising by roughly 1-2% annually. This contrasts sharply with the period of relatively stable emissions observed in the early 2010s. Projections for 2025 suggest a continuation of this trend unless substantial mitigation efforts are implemented.

To grasp the sheer scale of these emissions, consider some relatable comparisons. 36.6 billion tonnes of CO2 is an immense amount. Imagine filling the volume of New York City’s five boroughs – including all buildings, streets, and parks – roughly 17,000 times with compressed CO2 gas. Another way to visualize this weight is to compare it to the combined weight of the entire human population. With an estimated global population of 8 billion people and an average weight of 62 kg, the total human biomass is around 496 million tonnes. The annual fossil fuel CO2 emissions are more than 70 times this total human biomass. This highlights the truly staggering scale of our annual CO2 output. Today we can confidently say that the sheer volume of fossil fuels burned in a single year, and the resultant CO2 released, dwarfs the estimated total human biomass across all of history !

This massive release of CO2 directly impacts the concentration of CO2 in the atmosphere, measured in parts per million (ppm). Pre-industrial levels were around 280 ppm. By 2024, we've surpassed 420 ppm, representing an increase of over 50% since the industrial revolution. This rapid increase is unprecedented in at least the last 800,000 years, based on ice core data, and likely much longer.

The Earth's geological history provides valuable insights into similar periods of high CO2 concentrations. One notable example is the Paleocene-Eocene Thermal Maximum (PETM), which occurred approximately 56 million years ago, roughly 10 million years after the extinction of the non-avian dinosaurs 66 million years ago. During the PETM, a massive release of greenhouse gases, primarily CO2, caused a global temperature increase of 5-8°C. The exact causes of this CO2 release are still debated, but leading theories include massive volcanic activity in the North Atlantic Igneous Province, the release of methane hydrates from the ocean floor (triggered by initial warming), and the oxidation of large amounts of organic carbon. This event had profound consequences, including mass extinctions, ocean acidification, and significant alterations to ecosystems.

Could a PETM-like event happen today? The answer is a resounding yes, and in some ways, it's already underway. While the PETM unfolded over several thousand years, the current rate of CO2 increase is significantly more rapid. We are releasing CO2 into the atmosphere at a pace far exceeding any natural event in recent geological history. This rapid increase raises the potential for even more severe and accelerated consequences than those observed during the PETM. The primary difference is the cause: while the PETM was likely triggered by natural processes, the current increase is overwhelmingly driven by human activities, primarily the burning of fossil fuels. This makes the current situation even more alarming, as we have the potential to control the source of the problem.

Beside the expected event in the White House, today is also the birthday of Buzz Aldrin , the famous astronaut. I cannot think about him without imaging again the first pictures he shared with Neil Armstrong and the ones of the following missions both on Moon and in the space. The iconic images of Earth captured by Apollo 8 and Explorer 1, showing our planet as a small, vibrant blue marble suspended in the vast blackness of space, underscore the profound fragility of our existence. These images reveal the thinness of our atmosphere, a delicate layer that sustains all life and yet appears incredibly vulnerable against the backdrop of the cosmos. It is this thin veil of gases that regulates our planet's temperature, protects us from harmful radiation, and provides the air we breathe. We are rapidly altering its composition, with potentially catastrophic consequences. This atmospheric layer, so crucial for life as we know it, is a finite resource, and our actions are demonstrating just how quickly we can disrupt its delicate balance. The very fact that we can compare our current trajectory to a major geological event like the PETM should serve as a stark warning. The scale of human impact, capable of replicating events that unfolded over millennia in mere decades, highlights the urgency of the situation.

Despite the immense challenges we face, hope remains. Every individual action, every policy shift, and every technological advancement contributes to the global effort to combat climate change. We must continue to strive towards a sustainable future, diligently reducing emissions and protecting our precious planet. Every contribution remains key to reduce emissions.