Climate change: The next 5 years are set to be scorching

Humanity is heading towards a period of record heat. According to the latest United Nations projections, it is extremely likely that the next five years will see the Earth repeatedly cross the temperature threshold deemed safe by the international community, while also breaking the record for the hottest year ever recorded. This alarming finding underscores the urgency of acting in the face of climate change, which is intensifying at an unprecedented rate.

Earth on the verge of record low

The indicators are clear: global warming is not slowing down, but rather seems to be accelerating. The United Nations, relying on sophisticated climate models and in-depth analysis of recent atmospheric data, predicts an intensification of global average temperatures over the next five years. This period could see the planetary thermometer repeatedly exceed the symbolic limit of 1.5°C warming compared to pre-industrial levels, a goal set by the Paris Agreement to avoid the most devastating consequences of climate change. Satellite data and ground-based measurements converge towards this worrying trend, confirming a continuous increase in greenhouse gas emissions and their direct impact on the planet's energy balance. The hottest year ever recorded, a record that is constantly being broken, could be shattered during this critical timeframe. Predictive models, even those based on machine learning approaches like GraphCast or Pangu-Weather developed by institutions such as the ECMWF, agree on this upward trajectory of temperatures. Forecasting uncertainty remains, but the probability of reaching and exceeding these thresholds is now overwhelming.

This projection does not just concern global averages. It translates into an increase in the frequency and intensity of extreme weather events worldwide. Heatwaves will become longer and more intense, droughts more severe in some regions, while others could experience torrential rainfall. Understanding the complex mechanisms governing our atmosphere, particularly thanks to advances in AI applied to meteorology, allows for better anticipation of these phenomena. Neural networks trained on vast atmospheric databases, for example from the Copernicus program satellites, can now identify precursors of extreme events with increased accuracy. However, even these cutting-edge tools highlight the difficulty of predicting with certainty the exact magnitude of each event, reminding us of the importance of uncertainty management in weather and climate forecasting.

Understanding the acceleration of warming

Several factors explain this trend of accelerated warming. The natural El Niño-Southern Oscillation (ENSO) cycle plays a significant role. After a period of neutral phase or La Niña, the return of El Niño, an oceanic and atmospheric phenomenon that warms the equatorial Pacific waters, tends to increase global temperatures. El Niño releases a significant amount of heat stored in the ocean into the atmosphere, thus contributing to global temperature records. Scientists are closely monitoring signs of a possible return or intensification of El Niño in the coming years, which could amplify the greenhouse effect already increased by human activities. Climate models incorporate these natural cycles, but the dominant influence remains that of anthropogenic greenhouse gas emissions, primarily carbon dioxide (CO2) from the burning of fossil fuels and methane (CH4) from agriculture and hydrocarbon extraction.

The inertia of the climate system is also a key factor. Even if global greenhouse gas emissions were to stop tomorrow, the heat already trapped in the atmosphere and oceans would continue to warm the planet for decades. Oceans, which absorb over 90% of excess heat, play a crucial buffering role, but their absorption capacity has limits, and the rise in their temperature has disastrous consequences for marine ecosystems and ocean currents. Advances in AI, particularly the use of deep neural networks to analyze vast sets of satellite and in-situ data, allow for a better understanding of these complex interactions between the ocean, atmosphere, and cryosphere. These predictive models, such as those developed by world-renowned research centers like the ECMWF, are essential for refining our projections and anticipating potential tipping points in the climate system.

Implications and necessary actions

The consequences of these temperature records will be multiple and potentially devastating. Beyond heatwaves that will endanger the most vulnerable populations and exacerbate the risks of forest fires, the rise in global average temperatures will have a profound impact on ecosystems, agriculture, water availability, and human health. The melting of glaciers and ice sheets will accelerate, contributing to sea-level rise and threatening coastal areas. Extreme weather events, such as storms and floods, could become more frequent and intense in certain regions, causing considerable damage to infrastructure and economies. The need for rapid adaptation and ambitious mitigation of greenhouse gas emissions has never been more pressing.

In the face of these projections, the international community is called upon to redouble its efforts. This involves an accelerated transition to renewable energies, improved energy efficiency, more sustainable agricultural practices, and forest protection. AI-based technologies, such as the predictive models from GraphCast or Pangu-Weather, can play a crucial role by helping meteorologists and climatologists to better forecast extreme events and develop more effective adaptation strategies. Improved collection and analysis of atmospheric data, thanks to satellite constellations and ground sensor networks, are fundamental to feeding these models and reducing forecasting uncertainty. Collective and individual action is imperative to limit warming and build a more resilient future in the face of the climate challenges that await us.