The Paris Agreement commits countries to limiting their long-term warming to 1.5°C above pre-industrial levels. Long-term warming since pre-industrial times has already reached 1.2°C and global mean surface air temperatures have crossed the crucial 1.5°C warming threshold at the start of June this year (Figure 1), as the world’s oceans hit record-high temperatures for the past two months (According to the US National Oceanic and Atmospheric Administration, global ocean temperatures have reached their highest levels on record for April and May 2023 ) (Figure 2).
It will result in the water cycle becoming intense, and global annual precipitation will increase. Moreover, as the oceans and atmosphere warm up, a self-reinforcing feedback loop accelerates evaporation to cause further warming. If the trend continues, the level of global warming since the pre-industrial era presents a stark indicator of ‘worsening climate change’.
The Return of El-Niño
Scientists this month declared the return of El Niño, the weather phenomenon associated with the warming of the sea surface across the equatorial Pacific Ocean. However, the recent record heating of the Pacific waters is not necessarily a direct result of the global mean surface air temperature increase. Scientists felt El-nino’s effects in the previous years after it had been active, perhaps with a 3 to 4 months lag. Thus, El Niño will probably have ‘more Influence on the weather and climate in the year 2024 than in 2023’.
El-Nino’s Influence on the Rise in Sea-temperature
The ocean is experiencing unprecedented effects due to excessive heat and energy, such as melting ice, rising sea levels, marine heat waves, and ocean acidification caused by changes in temperature. Ocean warming reduces dissolved oxygen, increasing absorbed carbon dioxide (CO2) levels. A higher CO2 content causes oceans to become more acidic, which attacks and destroys the protective shell of corals and other microorganisms. They are a litmus test for the climate crisis’ effects at sea, as ocean temperature is a critical variable in the survival of interconnected ecosystems with consequences for all marine life.
Marine primary productivity or phytoplankton photosynthesis (Marine plankton are the lungs for the planet and Earth’s life support system) has declined by as much as 50% since the 1950s( as per the sources). According to data, the ocean covers about 71% of the Earth’s surface and has a surface microlayer that promotes the formation of aerosols and clouds. This layer also reduces the escape of water molecules and slows thermal energy transfer to the atmosphere. The concentration of water vapor in the atmosphere is increasing, and all of this increase is due to evaporation from the ocean surface. Therefore, the oceans are primarily responsible for climate change.
If phytoplankton plant growth decreases, it can negatively affect the ocean’s surface microlayer membrane and carbon assimilation and increase dissolved carbon dioxide concentrations. It leads to ocean acidification, which can cause a decline in key carbonate-based species and diatoms when the pH drops below 7.95, which is expected to happen by mid-century. Additionally, a decrease in the surface microlayer can cause increased evaporation and atmospheric water vapor concentrations, affecting aerosols, cloud formation, precipitation, humidity, and temperature. Clouds formed under these conditions can cause heavy downpours and flooding. Even if we achieve net zero by 2050, the potential consequences of catastrophic climate change are severe.
In parallel, the loss of marine biodiversity and the negative impact on the livelihood of coastal communities may result from both ocean acidification and the collapse of the marine ecosystem happening at the same time.
Biodiversity at Risk
While our planet’s biodiversity is at risk of collapse, we continue to exploit and consume without considering the consequences. For example, fisheries are depleted by rampant overfishing in many coastal water bodies, destroying certain fishery species. Recently we witnessed thousands of dead fish washed ashore on the Gulf Coast beach in the US. A sharp rise in the water temperatures affects the oxygen level compared to cooler water. When the water rises above 21oC, it can lead to these events occurring due to low oxygen levels in the sea.
Likewise, excessive logging activities in many forest areas have led to deforestation, degradation, and major wildfires are a matter of concern. A recent example of the Canadian wildfires causing mass evacuations and burning through millions of acres of land is the impact of dry and warm conditions. Climate change is a significant factor impacting the record heat and drought, leading to more lightning, but half of the wildfires are human-caused. Human-caused fires result from campfires left unattended, debris burning, equipment use and malfunctions, negligently discarded cigarettes, and intentional acts of arson. It can have a significant impact on the occurrence of wildfires and climate change alike.
The big question is: Can we allow this destruction to persist further?
This excess demand [for nature] is only about 50 years old, but there’s been an unprecedented acceleration in that demand since the second world war. It has come at an expense to natural capital. If the need for nature’s products and services, a finite resource, continues to exceed its ability to supply, then there will be a breakdown soon. Our societies are built on the relentless pursuit of economic growth, where profits trump the health of our planet. Our actions have, till now, prioritized short-term gains over long-term sustainability. But rising temperatures, record-high ocean temperatures, and the cross-over of crucial warming thresholds need our attention. Our ecosystems are suffering, and the warning signs are visible and apparent.