A few days before Christmas, Super-typhoon Rai – known locally as Odette – ravaged the Philippines. Lost lives continue to climb two weeks on. Vast numbers of buildings were destroyed – from houses to schools; food crops lost to flooding.
On average, 20 storms and typhoons hit the Philippines each year and they are growing progressively more destructive. The culprit is greenhouse-gas emissions from human activities. The Philippines contributes less than 0.4% to the climate crisis; the global north is responsible for 92%. The Philippines pays the price for problems produced in the north.
Despite the Philippines’ small part in the worsening climate crisis, the threat to the country is huge. Rising sea levels from global heating will submerge parts of the country, creating thousands of climate refugees. Drought and flooding will hit agricultural production and destroy ecosystems. The risk and intensity of health emergencies, such as dengue and diarrhoea, will increase.
Natural defences have not been protected. Dams have been built on ecologically important rivers; dolomite mining continues, and new coal-powered plants are still being built. A few days after the typhoon, a four-year ban on open-pit mining was lifted to help economic recovery, disregarding the contribution of mining to the typhoons and rainfall that are battering the economy in the first place.
The last time carbon dioxide levels were where they are today, at more than 415 parts per million, was 4 million years ago, and the result of the associated warming due to greenhouse gas was melting of the West Antarctic Ice Sheet and several meters of sea level rise. Unless we can bring our present atmospheric carbon dioxide level down, the eventual outcome will again be substantial loss of ice and open seas across West Antarctica.
Antarctic glaciers are melting in specific regions of West Antarctica in a mode that can’t be stopped. Ocean heat and the reverse slope of the marine continental shelf beneath the Thwaites Glacier, for example, is a runaway train, and large volumes of ice of the West Antarctic Ice Sheet will continue to enter the sea through this outlet.
Scientists from the United Kingdom and the United States are working together in this region to better understand the processes involved, to determine the rate and timing of changes, but this glacial system is in full-scale retreat.
Scientists have discovered a series of worrying weaknesses in the ice shelf holding back one of Antarctica’s most dangerous glaciers, suggesting that this important buttress against sea level rise could shatter within the next three to five years.
Until recently, the ice shelf was seen as the most stable part of Thwaites Glacier (shown on the left of the image above). Because of this brace, the eastern portion of Thwaites flowed more slowly than the rest.
Satellite images show several large, diagonal cracks extending across the floating ice wedge.
These weak spots are like cracks in a windshield, said Oregon State University glaciologist Erin Pettit. One more blow and they could spiderweb across the entire ice shelf surface. “This eastern ice shelf is likely to shatter into hundreds of icebergs,” she said. “Suddenly the whole thing would collapse.”
Even if the fractures don’t cause the shelf to disintegrate, it is likely to become completely unmoored from the seafloor within the next decade.
But when the shelf fails, the eastern third of Thwaites Glacier will triple in speed, spitting formerly landlocked ice into the sea. Total collapse of Thwaites could result in several feet of sea level rise, scientists say, endangering millions of people in coastal areas.
Without its protective ice shelf, scientists fear that Thwaites may become vulnerable to ice cliff collapse, a process in which towering walls of ice that directly overlook the ocean start to crumble into the sea. This process hasn’t been observed in Antarctica.
After the natural warming that followed the last Ice Age, there were repeated periods when masses of icebergs broke off from Antarctica into the Southern Ocean. A new data-model study led by the University of Bonn (Germany) now shows that it took only a decade to initiate this tipping point in the climate system, and that ice mass loss then continued for many centuries. Accompanying modeling studies suggest that today’s accelerating Antarctic ice mass loss also represents such a tipping point, which could lead to irreversible and long-lasting ice retreat and global sea level rise.
Rain has fallen on the summit of Greenland’s huge ice cap for the first time on record. Temperatures are normally well below freezing on the 3,216-metre (10,551ft) peak, and the precipitation is a stark sign of the climate crisis.
The rain fell during an exceptionally hot three days in Greenland when temperatures were 18˚C (32˚F) higher than average in places.
Rising sea levels and climate change are posing serious threats to the population and economy of several Asian coastal cities—Bangkok, Dhaka, Jakarta, Manila and Shanghai, among them.
Threats come from a combination of tropical cyclones, storm surges, high tides and sea-level rise that increase risk of serious flooding by 2030. Some 600 million people worldwide—the majority in Asia—will be affected by rising sea levels in flood-prone coastal regions, some of them economic centers.
Vietnam is in a class by itself with a high coastal plain population. By 2040, it is expected to experience a relatively high land loss due to submergence forcing people to migrate.
Jakarta reportedly holds the record for the world’s fastest sinking city, at a rate of around 25.4cm (1 inch) per year. Around 40% of the city now lies below current sea levels. Over half of its 10.6 million people lack access to piped water and surface water is heavily polluted, so they dig illegal wells to extract groundwater. Rains are not enough to replenish water in the soils because over 97% of Jakarta is covered in asphalt and concrete. The Indonesian government announced that they are planning to develop a new capital at an estimated cost of US$33 billion. The new city will relocate some 1.5 million people mostly civil servants and their families and economic actors. However, it seems that there is no commitment on the poor coastal folks in North Jakarta which will be left to deal with the unsolved land subsidence and rising seas.
Bangkok with its 9.6 million population is also vulnerable to rising sea levels. In 2015, its government published a report that said the city could be underwater in 15 years. The city, now only around 1.5 meters above sea level, is sinking at a rate of about 2cm (0.8 inches) per year. The city has about 700 buildings with 20 floors or more, and 4,000 buildings with 8—20 floors, putting considerable pressure on the land on which they sit.
Manila with its core city population of 13.3 million people is sinking at around 10cm (4 inches) per year. Since the city has an average elevation of around five meters (16 feet) it is living on borrowed time. The sinking increases the risk of floods and cause high tides to penetrate further inland and water to recede more slowly. Unless there is intervention, much of the land area bordering Greater Manila Bay—Pasay to Manila to Malabon to most of Bulacan province north of Manila—will go under several centimetres of water by 2050.
Bangladesh’s capital city of Dhaka, population 18.9 million, is another low-lying, riverside city in Asia beset by sinking caused by unsustainable groundwater extraction. The city is sinking at a rate of about 1.4 cm (0.6 inches) per year, with most urbanized areas a mere 6–8 meters above sea level. Sea level rise appears to be happening at a rate ten times greater than the global average in the Bay of Bengal, southwest of the city.
Certainly, a managed retreat should be inclusive for all, especially the most vulnerable and impoverished.