Extreme sea-level events ‘will hit on many coasts once a year by 2050’, irrespective of climate-warming emissions are cut or not, a landmark report by the world’s scientists disclosed. These catastrophic events used to occur once in a century.
Climate report says many severe impacts, including intense storms to the melting of permafrost and loss of marine life, are already inevitable and that is evident from the climate crisis in the world’s oceans and ice caps.
However, without urgent action to cut fossil fuel emissions impacts will be far severe, including the eventual rise of sea level for more than 4 meters in the worst case. In such a situation, it would require redrawing the map of the world, and billions of people will be affected.
The report from the Intergovernmental Panel on Climate Change (IPCC), approved by its 193 member nations, says that “all people on Earth depend directly or indirectly on the ocean” and glaciers and ice caps provide water and oxygen and regulate the climate. However, it is facing unprecedented and damaging changes due to global warming.
According to the IPCC report, with the increasing ice losses from Greenland and Antarctica, sea-level rise is accelerating. The ocean is getting hotter, less oxygenated, and more acidic, and these trends will continue until the end of the century.
Half of the world’s megacities are along the coasts with a population of almost 2 billion people. As per the scientists, even if heating is restricted to just 2C, the impact of sea-level rise will cause several trillion dollars of damage a year, and result in many millions of migrants.
“The future for low-lying coastal communities looks extremely bleak,” said Prof Jonathan Bamber at Bristol University in the UK, who is not one of the report’s authors. “But the consequences will be felt by all of us. There is plenty to be concerned about for the future of humanity and social order from the headlines in this report.”
The unexpectedly fast melting in Antarctica likely to increase sea level by 2100 higher than those it made in 2014, the new IPCC projections said. Unless carbon emissions are cut, the ocean is expected to rise between 61cm and 110cm, which is about 10cm more compared to the earlier estimate. As per the research, 10cm rise means an additional 10 million people getting exposed to flooding.
Where the IPCC considers the likely range of sea-level rise, not as the worst-case scenario, a recent expert analysis led by Bamber concluded that up to 238cm of sea-level rise remains possible by 2100, and many megacities will drown around the world. “This cannot be ruled out,” said Zita Sebesvari at the United Nations University, a lead author of the IPCC report.
The considerable immediate cuts in emissions even cannot stop sea level from rising between 29cm and 59cm because of the slowly melting ice caps and glaciers and without action, sea level will rise for centuries, Sebesvari warned. “The dramatic thing about sea level rise is if we accept 1 metre happening by 2100, we accept we will get about 4 metres by 2300. That is simply not an option we can risk.”
Very soon extreme sea-level impacts will be felt in many places well before 2050, Sebesvari said. The IPCC report states: “Extreme sea level events that [occur] once per century in the recent past are projected to occur at least once per year at many locations by 2050 in all scenarios.”
The IPCC report found the warming of oceans are causing more intense tropical storms with stronger winds and greater deluges of rain to batter coasts. For example, catastrophic flooding of Hurricane Harvey was made three times more likely by climate change.
The kelp forests and other essential ecosystems get damaged by the ocean heating with the searing marine heatwaves that doubled the underwater wildfires in the last 40 years. These are projected to increase by at least 20 times by 2100, the IPCC reported.
In this century, whether emissions are cut or not, extreme El Niño events, are likely to occur twice as often resulting in heatwaves in some regions and floods in others, the report said. However, if emissions are not slashed, coral reefs, vital nurseries for marine life, will face significant losses and local extinctions. The heat, acidification, and lower oxygen across the ocean would reduce fisheries by a quarter and all marine life by 15 percent.
The substantial reduction in Arctic ice also recorded in the IPCC report. The exposed darker ocean absorbs more heat from the sun than highly reflective ice that exacerbates global heating. In the 41-year satellite record the Arctic sea ice in 2019 shrank to its second-lowest extent, scientists announced on Monday.
The IPCC found the world’s high mountain glaciers are also melting fast, upon which almost 2 billion people rely for water while landslides are expected to increase. The vast Himalayan range is already doomed by one-third, with two-thirds projected to vanish with an increase in emissions.
IPCC report mentioned about the most alarming melting tundra and increasing wildfires in northern latitudes: “Widespread permafrost thaw is projected for this century and beyond.” As per the report, a quarter is already near-certain to melt, and 70% or more would happen if emissions are not curbed. Hundreds of billions of tonnes of carbon dioxide and methane could be released in the latter case, expediting the climate emergency.
“That risks taking us beyond the point where climate change could be easily constrained,” said Richard Black, at the UK’s Energy and Climate Intelligence Unit. “Nevertheless, the IPCC’s 2018 report concluded that governments can shrink emissions quickly enough to keep global warming to 1.5C if they choose. None can claim to be unaware of both the dangers of untrammelled climate change nor the feasibility of preventing it.”
Anne Hidalgo, the mayor of Paris and chair of the C40 Cities climate coalition, said the IPCC report was shocking. “Around 1.9 billion people and over half of the world’s megacities are all in grave danger if we don’t act immediately. Several cities, home to hundreds of thousands of people, are already disappearing underwater. This is what the climate crisis looks like now.”
Taehyun Park, of Greenpeace East Asia, said: “The science is both chilling and compelling. The impacts on our oceans are on a much larger scale and happening way faster than predicted. It will require unprecedented political action to prevent the most severe consequences to our planet.”
According to Sebesvari, along with cutting fossil fuel emissions, preparing for the inevitable impacts is also vital especially in poorer nations that lack the funds required to build sea walls, move settlements or restore protective coastal marshes.
“Action is needed now to secure the coast for our children and coming generations,” she said. The pressure now being exerted by the global school strikes for the climate was necessary, she said. “I have very strong motivation. I have two kids and we are really being tested by our kids on our actions.”