When asked about a particular weather event’s link to climate change, scientists are typically cautious to make definitive statements — especially in the immediate aftermath, before they’ve had the chance to study the event.
“Upside-down rivers” of warm ocean water threaten the stability of floating ice shelves in Antarctica, according to a new study led by researchers at the National Snow and Ice Data Center published today in Nature Geoscience. The study highlights how parts of Antarctica’s ice sheet may be weakening due to contact with warm ocean water.
“We found that warm ocean water is carving these ‘upside-down rivers,’ or basal channels, into the undersides of ice shelves all around the Antarctic continent. In at least some cases these channels weaken the ice shelves, making them more vulnerable to disintegration,” said Karen Alley, a graduate research assistant at NSIDC and lead author of the study. Alley is also a Ph.D. student in the University of Colorado Boulder’s Department of Geological Sciences.
Ice shelves are thick floating plates of ice that have flowed off the Antarctic continent and spread out onto the ocean. As ice shelves flow out to sea, they push against islands, peninsulas, and bedrock bumps known as “pinning points.” Contact with these features slows the flow of grounded ice off the continent. While ice shelves take thousands of years to grow, previous work has shown that they can disintegrate in a matter of weeks. If more ice shelves disintegrate in the future, loss of contact with pinning points will allow ice to flow more rapidly into the ocean, increasing the rate of sea level rise.
“Ice shelves are really vulnerable parts of the ice sheet, because climate change hits them from above and below,” said Ted Scambos, NSIDC lead scientist and study co-author. “They are really important in braking the ice flow to the ocean.”
The features form as buoyant plumes of warm and fresh water rise and flow along the underside of an ice shelf, carving channels much like upside-down rivers. The channels can be tens of miles long, and up to 800 feet “deep.”
When a channel is carved into the base of an ice shelf, the top of the ice shelf sags, leaving a visible depression in the relatively smooth ice surface. Alley and her colleagues mapped the locations of these depressions all around the Antarctic continent using satellite imagery, as well as radar data that images the channels through the ice, mapping the shape of the ice-ocean boundary.
The team also used satellite laser altimetry, which measures the height of an ice shelf surface with high accuracy, to document how quickly some of the channels were growing. The data show that growing channels on the rapidly melting Getz Ice Shelf in West Antarctica can bore into the ice shelf base at rates of approximately 10 meters (33 feet) each year.
The mapping shows that basal channels have a tendency to form along the edges of islands and peninsulas, which are already weak areas on ice shelves. The team observed two locations where ice shelves are fracturing along basal channels, clear evidence that basal channel presence can weaken ice shelves to the point of breaking in vulnerable areas.
While no ice shelves have completely disintegrated due to carving by basal channels, the study points to the need for more observation and study of these features, said co-author Helen Amanda Fricker of Scripps Institution of Oceanography at UC San Diego. “It's feasible that as ocean temperatures around Antarctica continue to rise, melting in basal channels could contribute to increased erosion of ice shelves from below.”
The study, “Impacts of warm water on Antarctic ice shelf stability through basal channel formation,” was led by University of Colorado Boulder Ph.D. student Karen Alley, who worked with coauthors Ted Scambos of NSIDC and Matthew Siegfried and Helen Amanda Fricker of Scripps Institution of Oceanography, UC San Diego. Their work was funded in part by NASA and the U.S. Geological Survey. More
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Amidst the recent release of scientific reports on climate change, the key message has been for urgent action to limit global warming, before time runs out.
The Intergovernmental Panel on Climate Change released their Synthesis Report on the 5th Assessment Report in October, the World Bank released the “Turn down the heat, confronting the new climate normal” report in November and the United Nations Environment Program released their “Bridging the 2014 Emission Gap Report” also in November.
According to the “Turn down the heat” report and an accompanying press release – climate change impacts such as extreme heat events may now be unavoidable because the Earth’s atmospheric system is locked into warming close to 1.5°C above pre-industrial levels by mid-century, and even very ambitious mitigation action taken today will not change this.
This does not mean, however, that long-term warming of 1.5°C is locked in, or that achievement of the 1.5°C warming limit, as called for by vulnerable countries like Pacific Islands, is no longer possible.
“What we see from the scientific literature is that it’s clear that we can indeed hold warming below 2 degrees in this century probably with the most aggressive mitigation emission reduction options. We can limit peak warming close to 1.5 degrees and slowly reduce that to below 1.5 degrees by 2100,” said Prof. Bill Hare of the Climate Analytics Group, Potsdam Institute.
“This is going to involve fairly major changes in policy settings now but this is what we are negotiating for, to have the emissions go down in the 2020’s and if we can do that fast enough then its technically and economically feasible to bring warming back to 1.5 degrees by the end of the century.”
“Those that are arguing it’s not possible are expressing a political judgment, not a scientific judgment.”
There will be climate change impacts experienced by several regions including the Pacific islands, before warming is reduced as limiting peak warming close to 1.5°C by mid century will still result in significant damage.
At the present levels of warming (about 0.8°C above preindustrial) the impacts of climate change are already being felt in many regions of the world. Continued damage is forecast to the coral reefs in the Pacific and other tropical oceans, there is the huge risk of damage to water supply resources in dry regions and substantial drops in crop yield in regions such as sub Saharan Africa.
“On top of that we’ll also be experiencing quite major increase in extreme heat events even for 1.5 degrees warming so whatever happens we’re going to have to go through some very severe changes,” explains Professor Hare.
Here in Lima, Peru at the 20th Conference of the Parties to the United Nations Framework Convention on Climate Change (UNFCCC COP20), the Pacific islands are calling for a 1.5 degree limit to global warming by 2100. The next two weeks of climate negotiations continue the work being done by the Pacific islands as members of the Alliance of Small Islands States, lobbying for the 1.5 degree limit to global warming to be agreed upon in Paris next year.
The new climate treaty is to be agreed upon by the end of December in 2015 in Paris.
“Strengthening the long-term temperature goal to 1.5 degrees is of critical importance for us. Even at the current temperatures, our small low lying islands are being battered by king tides, salt water intrusion, coastal erosion, coral bleaching, ocean acidification, loss of species and habitats,” said Ms. Ana Tiraa, Head of the Cook Islands delegation at the UNFCCC COP 20.
“These will only be exacerbated at higher temperatures, with due respect to other parties, the Cook Islands calls for ambition levels that are high enough to keep temperature rise below 1.5 degrees. Temperature rises above 1.5 degrees cannot be an option for low lying small islands if we have a hope of surviving.”
According to Prof. Hare, at present there is confidence that with aggressive mitigation action warming can be held to below 2 degrees yet another decade of inaction will most likely lead to warming at 2 degrees or above. The message is clear that the time for action is now.
“It is still feasible to bring global warming to below 1.5 degrees by 2100 but whether or not the world politics and major economies will take enough action in the coming five to 20 years is in question. We are entitled to be skeptical given the inaction that has characterised the last decade as to whether that looks happening but it’s not a scientific judgment or statement, the option is well and truly open to bring warming back to below 1.5 degrees. More
Portraits of Resilience | Christine Germane | TEDxRenfrewCollingwood
Published on Nov 26, 201 4 • This talk was given at a local TEDx event, produced independently of the TED Conferences. Listen as photographer and educator Christine Germane tells the stories of Portraits of Resilience, a unique project that illustrates the ethical dimension of the climate change discussion through documenting and sharing the personal stories of indigenous youth. Since 2000, Christine Germane has been collaborating with Indigenous communities as a photographer, educator and curator. The international photojournalism project titled Portraits of Resilience has allowed her to work with indigenous youth to illustrate the personal and ethical effects of climate change on their communities. Since its creation in 2008, the project has occurred in 12 countries and has been exhibited internationally, including the launch at the National Museum of Denmark. With a range of education, awards, and project coordination experience within art and design under her belt, Christine’s exceptional work has provided youth with a medium to share their voice during a crucial period of time.
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My name is Milañ Loeak, I’m from the Marshall Islands, and I bring you a message on behalf of my Climate Warrior brothers and sisters from across Oceania.
You’ve probably heard it all before — that the climate is changing, that the ocean is rising, that my home in the islands will be the first to go. But the people of the Pacific are not drowning, we are fighting. And the biggest threat to our homes is the fossil fuel industry.
So here’s how we’re fighting back: there’s a coal port in Newcastle, Australia and it’s the largest in the world, shipping approximately 617,000 tons of coal every single day. If the port were a country, it would be the 9th highest emitting country in the world. That’s why I have travelled to Australia to shut it down for a day.
Using traditional canoes, I and 30 other Pacific Climate Warriors are going to paddle into the oncoming path of coal ships. Behind us will be hundreds of Australians in kayaks, on surfboards and whatever else they can find, united with us as we stand up to the fossil fuel industry.
The fossil fuel industry will try to dismiss us. They will launch their PR machine to say that we are just a small group acting alone and that we do not speak for others. But we know that we are not acting alone. We are standing with front line communities around the world when we say it is time to end our addiction to fossil fuels before it destroys our homes, our communities, and our culture.
Stopping one day of coal exports alone won’t keep our homes above water, but it marks the rise of the Pacific Climate Warriors, and the beginning of our defense of the Pacific Islands.
I ask you to join us in this fight — because we cannot save the Pacific Islands on our own.
Warm Pacific wishes,
Milañ Loeak, Republic of the Marshall Islands
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That solar photovoltaic (PV) technology is poised to become a dominant energy generation technology throughout the world is of no surprise to most, but the sheer wealth of possibility being forecast throughout the middle and southern hemispheres begins to give an idea of just how prevalent the technology will be by the end of the decade.
Figures published by NPD Solarbuzz have so far predicted that several of the major Asia Pacific nations will account for 60% of solar PV demand in 2014, while being primary drivers of growth over the next several years, at the same time as the Middle East and Africa region currently has close to 12 GW of solar demand in the pipeline.
So it should really come as no surprise that NPD Solarbuzz’s recent figures show that the Latin America and Caribbean region is set to install 9 GW of solar PV over the next five years.
Latin America and Caribbean Five-Year Cumulative Demand Forecast by Project Status
“Solar PV is now starting to emerge as a preferred energy technology for Latin American and Caribbean countries,” said Michael Barker, senior analyst at NPD Solarbuzz. “The region has high electricity prices and it also benefits from strong solar irradiation, which makes it a good candidate for solar PV deployment. As a result, experienced global solar PV developers are seeing strong solar PV growth potential in the region.”
NPD Solarbuzz’s Emerging PV Markets Report: Latin America and Caribbean shows that the total PV project pipeline now exceeds 22 GW of projects across all stages of development — with 1 GW of projects already under construction, and another 5 GW of projects have received the appropriate approval to proceed.
The Latin America and Caribbean region was previously home to many small-scale and off-grid solar PV applications, however governments are now looking to solar PV to address large-scale utility power requrements — specifically in Brazil, Chile, and Mexico.
“Many countries across the LAC region have the potential to develop into major solar PV markets in the future,” added Barker. “While project pipelines vary by country, there is a strong contribution from early-stage developments that have yet to finalize supply deals or find end-users to purchase the generated electricity, which presents both risks and opportunities for industry players.”
A number of countries throughout the developing and second-world countries are turning to renewable energy technologies to develop strong, future-proof, and economically efficient energy generation. Such a trend is being backed by major manufacturing companies who are focusing their efforts on these regions, hoping to increase their own profits while fulfilling renewable energy demand. More