O Intergovernmental Panel on Climate Change (IPCC), the UN body responsible for dealing with global warming, presented a report last Wednesday (25) The Ocean and Cryosphere in a Changing ClimateThe document addresses the effects of climate change on Earth's oceans and permafrost. The devastation of seas and ice sheets due to climate change is the major problem highlighted in the document.
According to Alexander Turra, a marine ecology and coastal management specialist at the USP Oceanographic Institute, the report shows that the problem of climate change is serious, real, and urgent. "The results are supported by unequivocal scientific data. There is no margin for error in these conclusions. We are far from being part of any kind of international conspiracy. The Brazilian perspective, conveyed in the president's speech at the United Nations General Assembly, reinforced the federal government's understanding that climate science is not fact, that it is an ideological and conspiratorial approach. It is not. And this is proven," he declared.
Rising temperatures are contributing to declining fish populations in several regions, and ocean oxygen levels are falling, posing a risk to important marine ecosystems. Warmer ocean waters, combined with rising sea levels, also fuel even more powerful tropical cyclones and floods, the report adds. This puts coastal regions at risk and exacerbates the phenomenon that is already contributing to storms like Hurricane Harvey.
“The oceans are sending us many warning signals that we need to get emissions under control,” said Hans-Otto Pörtner, a marine biologist at the Alfred Wegener Institute in Germany and one of the report’s authors. “Ecosystems are changing, food webs are changing, fish stocks are changing, and all this turmoil affects humans.”
The oceans have served as a buffer against global warming, absorbing about a quarter of the carbon dioxide emitted by humans from power plants, factories, and cars, and absorbing more than 90% of the excess heat trapped on Earth by carbon dioxide and other greenhouse gases. Without this protection, land areas would be warming much faster.
However, the Report points out that the oceans are warming and losing oxygen. If humans continue to emit greenhouse gases into the atmosphere at an ever-increasing rate, the risks to human food security and coastal communities will increase, especially since marine ecosystems already face threats from waste pollution, unsustainable fishing practices, and other human-caused stresses.
“We are one ocean world, driven and operated by one ocean, and we are pushing this life-support system to its extreme limits through warming, deoxygenation, and acidification,” said Dan Laffoley of the International Union for Conservation of Nature, a leading ecological organization that tracks the status of plant and animal species, in response to the report.
The oceans and human life
For oceanographer Jonas Santos, the oceans have gained attention due to climate change and rising sea levels. "The ocean has and will continue to have a significant influence on climate regulation through the absorption, storage, and transport of heat, carbon dioxide, and water. Changes in ocean circulation can produce considerable, anomalous, and perhaps irreversible changes in Earth's climate," he assesses.
Various mineral resources are extracted from the sea, such as magnesium, used in metal alloys. The chemical element bromine is used in various industries, such as pharmaceuticals and food. Salt, which we use in cooking, is the most important mineral obtained directly from seawater. Oceanographer Jonas also shows that seaweed produces approximately 55% of the world's oxygen. "Excess carbon dioxide (CO2) in the atmosphere is absorbed by the water. Through photosynthesis, algae produce much more oxygen than they need, and when there is too much oxygen in the water, it is released into the atmosphere," explains the oceanographer.
Given the importance of the oceans to human beings, the oceanographer reminds us that everyone is responsible for protecting them. "It sustains life on Earth, and humans must live in a way that contributes to this sustainability. Individual and collective actions are necessary to effectively manage the ocean's resources so that they reach everyone," he emphasizes.
