State of the Planet

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Melting Ice and Rising Sea Levels: Why 2 Degrees Celsius Is Too High

At the annual June climate negotiations in Bonn, Germany, a gathering of mountain, polar and low-lying nations came together in a United Nations Framework Convention on Climate Change (UNFCCC) side event. The event, titled “Loss of Mountain Water Resources and Sea-level Rise: Why 2°C is Too High for 3.5 Billion,” focused on the implications of the planet’s steadily disappearing ice for climate ambition and mitigation, loss and damage, and adaptation.

The Bonn meetings of the UNFCCC subsidiary bodies, known as “SB58,” run this year from June 5 to 15. Although largely scientific and technical in nature, these meetings come at a key moment in the UNFCCC process, laying the groundwork as negotiators prepare for COP28 in December, with the United Arab Emirates as COP President. The event made clear that major negotiation tracks such as mitigation, loss and damage, and adaptation are deeply interconnected with the physical realities of snow and ice melt. As stated by the annual State of the Cryosphere Report published during COP27, “There is no negotiating with the melting point of ice.”

Three researchers sit in front of a slideshow with a glacier image.
Joanna Post (United Nations Framework Convention on Climate Change secretariat), Eduardo Silva from Chile, and Annika Christell from Sweden at a June SB58 side event in Bonn, Germany. Photo: ICCI

The side event built in part on a pre-session cryosphere workshop — the first of its kind at a UNFCCC negotiation — under the auspices of the Ambition on Melting Ice (AMI) High-level Group on Sea-level Rise and Mountain Water Resources, which includes countries not just in polar and mountain regions, but also coastal and low-lying nations vulnerable to loss of water from snowpack and glaciers, as well as sea-level rise from the Greenland and Antarctic ice sheets.

At the event, negotiators from a wide range of countries raised their concern about the impacts of cryosphere loss, including Eduardo Silva from Chile (AMI co-chair country); Carlos Fuller from low-lying Belize; Annika Christell from polar Sweden; and Namgay Choden, a youth delegate from the Himalayan nation of Bhutan. Together, these negotiators united with lead scientists to provide a clear message: 2 degrees Celsius of warming is too high.

“Fifty percent of the population of the Caribbean lives along the coastal zone,” said Fuller, on the necessity of urgent emissions reductions to keep global temperatures below 1.5 degrees Celsius. He continued, “At the end of the day, if this is not done now, we already see the mass migration occurring from Africa into Europe, from the Americas into the U.S. It’s going to get far worse unless we start to address it right now.”

Woman wearing scarf sits opposite a microphone.
Izabella Koziell, deputy director of the International Centre for Integrated Mountain Development, at the UNFCCC side event. Photo: ICCI

An overview of the latest snow and ice science examined at the pre-session workshop was given by Pam Pearson, director of the International Cryosphere Climate Initiative (ICCI), which serves as the secretariat of AMI. Izabella Koziell, deputy director of the International Centre for Integrated Mountain Development (ICIMOD) supporting eight regional member countries, gave the keynote address, outlining the challenges facing the Hindu Kush Himalaya region.

Major dynamics including ice sheets, mountain glaciers and snow, permafrost, sea ice and polar oceans have critical thresholds around 1.5 to 2 degrees Celsius of warming, with the potential to unleash devastating consequences on communities across the world. A Nature study published last week underscores this message.

Koziell described the pivotal role of glaciers and snow in the Hindu Kush Himalaya, a region where mountains offer the largest frozen water store outside of the poles. “1.5 degrees Celsius is already within our sights, as we heard from the WMO [World Meteorological Organization] recently, and that is already too hot because the impacts are already present,” she said. “The potential implications of going 1.5 degrees Celsius and beyond are enormous and will affect us all.”

“We are rapidly losing our glaciers, and that will not only impact our water and food security,” said Choden. “GLOFs [glacier lake outburst floods] will cause huge risks to forests and biodiversity, infrastructure, people, and the economy…[including] hydropower and agriculture, two of the most vulnerable sectors to climate change, closely related to the stability of the cryosphere.”

Urgent emissions reductions are essential for addressing the climate crisis and reducing the far-reaching, long-term and intergenerational consequences of snow and ice loss on a global scale.  “Knowing what we know today, 2 degrees Celsius should not even be on the table,” Fuller said.

The event was co-organized by the Scientific Committee on Antarctic Research (SCAR), as well as ICCI and ICIMOD, and may be viewed at:


Amy Imdieke is the global outreach director of the International Cryosphere Climate Initiative.

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Erik Frederiksen
Erik Frederiksen
1 year ago

From NASA’s former lead climate scientist James Hansen in 2016:

“There’s no argument about the fact that we will lose the coastal areas, now occupied by most of the large cities of the world. It’s only a question of how soon. That message, I don’t think, has been clearly brought to the policymakers and the public.

That loss of coastal cities would be a dangerous outcome. It’s hard to imagine that the world will be governable if this happened relatively rapidly.

What we conclude is that the timescale for ice-sheet disintegration is probably a lot shorter than has been assumed in the intergovernmental discussions.”