Nav: Home

Melting ice sheets may cause 'climate chaos' according to new modelling

February 06, 2019

The weather these days is wild and will be wilder still within a century. In part, because the water from melting ice sheets off Greenland and in the Antarctic will cause extreme weather and unpredictable temperatures around the globe. A study published today in Nature is the first to simulate the effects, under current climate policies, that the two melting ice sheets will have on ocean temperatures and circulation patterns as well as on air temperatures by the year 2100.

Consequences for ocean circulation and water and air temperatures

"Under current global government policies, we are heading towards 3 or 4 degrees of warming above pre-industrial levels, causing a significant amount of melt water from the Greenland and Antarctic Ice Sheets to enter Earth's oceans. According to our models, this melt water will cause significant disruptions to ocean currents and change levels of warming around the world," says Associate Professor Nick Golledge from Victoria University of Wellington's Antarctic Research Centre in New Zealand. He led the international research team made up of scientists from Canada, New Zealand, the UK, Germany and the USA.

The research team combined highly detailed simulations of the complex climate effects of the melting with satellite observations of recent changes to the ice sheets. As a result, the researchers have been able to create more reliable and accurate predictions of what will occur under current climate policies.

Warming in Eastern Canada and cooling in Northwestern Europe

Professor Natalya Gomez, from the Department of Earth and Planetary Sciences at McGill contributed to the study by modelling projected changes to water levels around the globe as ice melts into the ocean. The ice sheet simulations suggest that the fastest increase in the rise of sea levels is likely to occur between 2065 and 2075. Melting ice sheets will affect water temperatures and circulation patterns in the world's oceans, which will in turn affect air temperatures - in a complex ice-ocean-atmosphere feedback loop.

"Water levels would not simply rise like a bathtub," says Gomez. "Some areas in the world, such as the island nations in the Pacific, would experience a large rise in sea level, while close to the ice sheets the sea level would actually fall."

However, the effects of ice sheet melt are far more widespread than simply leading to changes in sea levels. As warmer melt water enters the oceans, for example in the North Atlantic Ocean, major ocean currents such as the Gulf Stream will be significantly weakened. This will lead to warmer air temperatures in the high Arctic, Eastern Canada and Central America, and cooler temperatures over northwestern Europe on the other side of the Atlantic.

New information to help shape future climate policies

According to the researchers, current global climate policies set in place under the Paris Agreement do not take into account the full effects of ice sheet melt likely to be seen in future.

"Sea level rise from ice sheet melt is already happening and has been accelerating in recent years. Our new experiments show that this will continue to some extent even if Earth's climate is stabilized. But they also show that if we drastically reduce emissions, we can limit future impacts," says Golledge.
-end-
To read "Global environmental consequences of 21st century ice sheet melt" by Nicholas Golledge et al in Nature: https://www.nature.com/articles/s41586-019-0889-9

The research was funded by NASA, New Zealand's Royal Society Te Aparangi, the Antarctic Research Centre, the New Zealand Ministry for Business, Innovation and Employment, the Deutsche Forschungsgemeinschaft, and NSF Antarctic Glaciology Program.

Contacts:

Natalya Gomez, Department of Earth and Planetary Sciences, McGill University Natalya.gomez@mcgill.ca (English interviews only)

Katherine Gombay, Media Relations, McGill University Katherine.gombay@mcgill.ca, 514 398-2189

http://www.mcgill.ca/newsroom/http://www.twitter.com/mcgillu

McGill University

Related Sea Level Articles:

Researchers untangle causes of differences in East Coast sea level rise
For years, scientists have been warning of a so-called 'hot spot' of accelerated sea-level rise along the northeastern US coast, but understanding the causes has proven challenging.
Sea level as a metronome of Earth's history
Sedimentary layers contain stratigraphic cycles and patterns that precisely reveal the succession of climatic and tectonic conditions that have occurred over millennia.
Migration from sea-level rise could reshape cities inland
Researchers estimate that approximately 13.1 million people could be displaced by rising ocean waters.
Short-lived greenhouse gases cause centuries of sea-level rise
Even if there comes a day when the world completely stops emitting greenhouse gases into the atmosphere, coastal regions and island nations will continue to experience rising sea levels for centuries afterward, according to a new study by researchers at MIT and Simon Fraser University.
Climate change could trigger strong sea level rise
About 15,000 years ago, the ocean around Antarctica has seen an abrupt sea level rise of several meters.
Historical records may underestimate global sea level rise
New research from scientists at University of Hawai'i at Mānoa, Old Dominion University, and the NASA Jet Propulsion Laboratory shows that the longest and highest-quality records of historical ocean water levels may underestimate the amount of global average sea level rise that occurred during the 20th century.
Volcanic eruption masked acceleration in sea level rise
The cataclysmic 1991 eruption of Mount Pinatubo in the Philippines masked the full impact of greenhouse gases on accelerating sea level rise, according to a new study.
Pacific sea level predicts global temperature changes
Sea level changes in the Pacific Ocean can be used to estimate future global surface temperatures, according to a new paper in Geophysical Research Letters.
Climate change already accelerating sea level rise, study finds
Greenhouse gases are already having an accelerating effect on sea level rise, but the impact has so far been masked by the cataclysmic 1991 eruption of Mount Pinatubo in the Philippines, according to a new study led by NCAR.
As sea level rises, Hudson River wetlands may expand
In the face of climate change impact and inevitable sea level rise, Cornell and Scenic Hudson scientists studying New York's Hudson River estuary have forecast new tidal wetlands, comprising perhaps 33 percent more wetland area by the year 2100.

Related Sea Level Reading:

Best Science Podcasts 2019

We have hand picked the best science podcasts for 2019. Sit back and enjoy new science podcasts updated daily from your favorite science news services and scientists.
Now Playing: TED Radio Hour

Changing The World
What does it take to change the world for the better? This hour, TED speakers explore ideas on activism—what motivates it, why it matters, and how each of us can make a difference. Guests include civil rights activist Ruby Sales, labor leader and civil rights activist Dolores Huerta, author Jeremy Heimans, "craftivist" Sarah Corbett, and designer and futurist Angela Oguntala.
Now Playing: Science for the People

#521 The Curious Life of Krill
Krill may be one of the most abundant forms of life on our planet... but it turns out we don't know that much about them. For a create that underpins a massive ocean ecosystem and lives in our oceans in massive numbers, they're surprisingly difficult to study. We sit down and shine some light on these underappreciated crustaceans with Stephen Nicol, Adjunct Professor at the University of Tasmania, Scientific Advisor to the Association of Responsible Krill Harvesting Companies, and author of the book "The Curious Life of Krill: A Conservation Story from the Bottom of the World".