In a strange event that contrasts with Europe’s Mediterranean and the unprecedented temperatures in the North Atlantic, the eastern Pacific Ocean is cooling. If this phenomenon, known as the “cold tongue” continues, it could reduce greenhouse gas warming by 30 percent. However, it could also bring intense drought to the U.S., and influence weather and climate around the world.
Over the course of several years, climate models have consistently projected that with the increasing levels of greenhouse gas emissions, ocean waters would undergo warming. These projections have, for the most part, proven to be accurate. However, in a distinct region of the Pacific Ocean, an intriguing phenomenon is unfolding. Extending westward from the coast of Ecuador for thousands of kilometres, a unique section of water has been exhibiting an unexpected cooling trend over the past three decades. The question arises: What factors are causing this particular area in the eastern Pacific to defy the anticipated warming trends predicted by climate models?
The challenge lies in the lack of understanding regarding the reasons behind this cooling trend, which consequently leads to uncertainty about its future trajectory. Without comprehension of the underlying mechanisms, we remain uncertain about when this cooling will cease, or if it might unexpectedly transition into a warming phase. This enigma holds immense global significance.
The fate of this cold tongue phenomenon could hold the key to crucial outcomes around the world. For instance, it might determine whether regions like California experience prolonged and unyielding droughts or if Australia contends with increasingly devastating wildfires. Additionally, it significantly influences the intensity of monsoon seasons in India and the likelihood of famine in the Horn of Africa. Moreover, it could even play a role in altering the overall impact of climate change on a global scale by affecting the sensitivity of Earth’s atmosphere to the rising levels of greenhouse gas emissions. Understanding and forecasting the behaviour of the cold tongue thus becomes vital for making informed decisions to mitigate and adapt to the effects of climate change.
Climate scientists are approaching this situation with a growing sense of urgency, as they strive to unravel the mysteries behind this phenomenon. However, the elusive nature of the cooling trend has led to widespread confusion and the emergence of numerous competing theories among the scientific community. The complexity of the Pacific Ocean’s behaviour in this region poses a significant challenge, making it difficult to pinpoint the exact mechanisms responsible for this unexpected cooling. It has yet to be solved and fully understood.
