The UK Prime Minister Boris Johnson said on Sunday (12 December) that Britain was facing a “tidal wave” of infection from the Omicron coronavirus variant. News headlines warn of “floods” of patients overwhelming hospitals. Indeed, panic is setting in around the world as the deluge of Covid updates continues and the West worries that Christmas will be cancelled. The news, however, that cities, including London, could experience regular, devastating flooding and some island communities disappear altogether because of increasingly dramatic melting in Antarctica is on few people’s radar.
We hear a lot about atmospheric warming – Cop26 was focused on holding global heating at 1.5°C – but very little about the warming of the oceans. Yet, it is warmer seas that are causing ice in Antarctica to melt. The ocean has absorbed vast quantities of heat as greenhouse gas emissions have shot up. Data from the US National Oceanic and Atmospheric Administration shows the temperature of the upper few metres of the ocean has increased by approximately 0.13°C every decade for the last 100 years. If the same amount of heat that has gone into the top 2,000 metres of the ocean between 1955 and 2010 had gone into the lower 10 kilometres of the atmosphere, the Earth would have warmed by a petrifying 36°C, suggests analysis by the Grantham Institute.
All this heat has caused giant fractures in the Thwaites glacier, researchers reported in the US this week. This is no small matter, but coverage of the news has been scarce compared with that of the pandemic. The glacier is the size of Britain. These cracks could cause it to collapse, shattering part of the ice shelf, which blocks the glacier from falling into the sea, and pushing up sea levels.
“Thwaites is the widest glacier in the world,” said Ted Scambos, lead coordinator for the International Thwaites Glacier Collaboration. “The glacier holds enough water to raise sea levels by over two feet [0.6m]. And it could lead to even more sea-level rise, up to 10 feet [3m]. If Thwaites were to collapse, it would drag most of West Antarctica’s ice with it.”
Erin Pettit, a glaciologist at Oregon State University, described the situation as “similar to that car window where you have a few cracks that are slowly propagating, and then suddenly you go over a bump in your car and the whole thing just starts to shatter in every direction”.
Exactly what will happen next to the glacier is not fully understood, but there is no doubt radical action is needed to slash emissions if the worst is to be avoided. “This a worrying development that very much underscores the urgency of efforts to decarbonise our civilisation,” said US climate scientist Michael E Mann.
Sea levels have risen by only around 20 centimetres over the last 120 years, but the worry is that the rate of change is speeding up. In the last three decades, they have shot up by 10cm, roughly equalling the amount over the preceding 70 years. Compounded by more violent storm surges, also the result of a warming world, major coastal flooding is becoming a bigger problem, with serious social and economic implications – think New York in 2012 or New Orleans in 2005. And the potential for destruction is immense, with around 680 million people or 10 per cent of the world’s population living in low-lying coastal regions.
“It is certainly not too late to reduce risks like this, including in other parts of Antarctica and in Greenland, of glaciers melting and a huge and irreversible melting of ice,” Peter Stott, a veteran scientist with the Intergovernmental Panel on Climate Change, told the New Statesman. “But for this particular glacier it may be already too late. Once the cracking of the ice shelf accelerates too far, the process of melting reaches a point of no return.”
More research is needed to understand if this is the case for Thwaites, but progress is being hampered by a lack of funding and scientists working on ocean – as opposed to atmospheric – warming, said Martin Siegert, glaciologist and co-director of the Grantham Institute at Imperial College. “We have got some brilliant minds, but we are only a small community and we need to penetrate our knowledge into the decision-making and insurance communities. We need a substantial increase in funding to allow the required advances in modelling technology and measurements.”
Without such knowledge and urgent climate action, sea levels are likely to rise many metres. Once that melting has begun, there will be nothing future generations can do to stop it, warned Stott.
A rise of a couple of metres would cause islands like Tuvalu to disappear, be an “existential threat” for low-lying countries like Bangladesh and the Netherlands, and constitute a “major problem” for cities like London, Shanghai and New York well before the end of the century, said Siegert. A new Thames Barrier would be needed, while a rise of between 2m and 5m would be “disastrous for London”.
It is vital that even during a pandemic, the public and governments keep their finger on the pulse and ensure news about climate change does not get washed away. Decisions made today will help the world avoid catastrophes much worse than Covid in the future.