Keeping Cold

By Michael Gregson | Published: 2:00 AM Jan 14 2021
Columns Keeping Cold

By Michael Gregson

Wrapping up is essential in snow-capped mountains – but not just to keep the cold out. Scientists have also shown it can be just as important to keep the cold in to help preserve the world’s dwindling glaciers.

Disappearing glaciers and ice sheets might not seem to be much of a problem for a tropical island like Sri Lanka – but in fact they could pose a major threat in the coming years. 

All islands and coastal regions are at risk from the melt water flowing into the sea around the globe.  Sea levels could rise by more than one metre by the end of the century, putting millions of lives at risk, according to a new study published in the journal One Earth.

Lead author Professor Martin Siegert, from Imperial College London, said: “Greenhouse gas emissions are still on the rise, and strong heating, of more than 4°C by 2100, is well within the realm of the possible if emissions continue unabated. Currently, hundreds of millions of people live in regions susceptible to coastal flooding, and the likelihood of even worse flooding will significantly increase with severe sea-level rise. The sea-level rise we have already faced has been somewhat mitigated by flood barriers and other measures, but we are unprepared for higher rates of rise that could overwhelm these measures. If we don’t do more to avert dangerous global heating, we may reach a point where we can no longer protect people.”

As well as attempting to slow global warming, efforts are underway at more local levels to slow the melting of glaciers. In China scientists have found using blankets to protect vulnerable glaciers from melting amid rising temperatures can help retain significant quantities of ice.

The Chinese Academy of Sciences conducted an experiment on a 500- square-metre section of the Dagu Glacier in northwest Sichuan Province in August 2019, in which they covered the area with geotextile blankets, a type of environmentally-friendly fabric.

After two and a half months, they found the area insulated by the blankets had ice up to one metre thicker than areas without blankets.

The experiment “demonstrates the blankets’ capacity to block solar radiation and heat exchange on the surface of the glacier”, said scientist Wang Feiteng, according to Shanghai Daily.

As the melting of glaciers around the world has gained pace due to the global climate crisis, smaller glaciers with an area smaller than 1 square kilometre are at particular risk, and “might soon disappear without human intervention”, Mr Wang said.

But despite the threat, the majority of research continues to focus on the mechanisms contributing to melting, rather than finding solutions to glacial melting, he said.

He told the newspaper the study team will pilot the heat-blocking method on other glaciers in China which have already been severely affected by climate change.

The experiment was apparently inspired by pre-refrigerator summers, when ice-cream would be stored beneath quilted blankets.The geotextile material used in the experiment is designed to block heat and reflect light in order to protect the ice underneath.

The study follows research published in November which revealed that glaciers in China’s remote Qilian Mountains are melting at a “shocking” pace due to the climate crisis, and could ultimately result in crippling water shortages for the region.

Rising temperatures have meant glaciers are now in retreat, and the process is getting faster.The largest glacier in the mountains, on the arid north-eastern edge of the Tibetan plateau, has retreated about 450 metres since the 1950s, when researchers set up China’s first monitoring station to study it.

Since monitoring began in the 50s, average temperatures in the area have risen about 1.5C, and with no sign of an end to warming, the outlook is grim for the 2,684 glaciers in the Qilian range.

There are precedents for glacier-wrapping. Swiss people living near the Rhône glacier have been doing it for more than a decade. Geotextiles are laid over the Presena glacier in northern Italy after every skiing season – with coverage now reaching 100,000 square metres. 

Janos Pasztor, executive director of the Carnegie Climate Governance Initiative agrees that glacier-wrapping experiments like that at Dagu could have a beneficial effect – but that the broader impacts should also be studied.

“Glacier-wrapping may have the positive impact of ‘saving’ the glacier. But it may have some other negative impacts as well, that people haven’t discovered,” he said.

By Michael Gregson | Published: 2:00 AM Jan 14 2021

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