Tag Archives: climate change

Larsen C in the News

The crack in the Larsen C ice shelf has been in the news recently. For instance Newsweek’s Another Huge Crack has Appeared on the Antarctica’s Larsen C Ice Shelf or the BBC’s The Crack that is Redrawing the World’s Map. Both articles seem to stem from the Project Midas news release A new branch of the rift on Larsen C (they made the map here).  The Newsweek article notes:

Current projections indicate that if the Larsen C ice shelf disintegrates, it could raise sea levels by up to 10cm.

A NASA report, Breaking the ice: Antarctic rifts and future sea level is a little more precise:

Yet even if the whole ice shelf were to break up, Fricker said, the resulting sea level rise would be minimal. The glaciers held back by the shelf are not so imposing.

“The Larsen C ice shelf only holds back about one centimeter of global sea level rise,” she said.

Still, the crack in Larsen C could be a bellwether for ice shelves elsewhere on the continent, Rignot said.

“What we are seeing on Larsen C has implications for the big ice shelves farther south that hold considerable (sea level) potential,” he said. The loss of these larger ice shelves and the resulting acceleration of glacial calving could amount to meters of sea level rise in the decades and centuries to come.

The NASA article does provide some balance:

Ice shelf demise, or business as usual?

The crack could be the start of a period of sustained retreat, similar to what happened to Larsen B, said Ala Khazendar, a JPL scientist who has investigated both Larsen B and Larsen C. An increasingly weakened ice shelf allows glaciers to speed their flow into the ocean, and the shelf, unable to recover its former bulk and solidity, disintegrates.

Or, this could turn out to be a normal calving episode.

“We have no way yet of knowing whether Larsen C is doing what Larsen C has been doing for thousands of years, or whether we are witnessing the beginning of the end of Larsen C,” he said.

If you are talking about climate change in the classroom, the NASA article is excellent for further readings and discussion as well as the Project Midas site. There is some interesting science here in understanding ice.

Greenland Ice Mass and Data

Vital Signs of the Planet from NASA is a place for graphs and data. The graph here is change in the mass of the Greenland Ice Sheet. On the Land Ice page there is also a graph of changes in the Antarctica Ice. Underneath each graph is a link to data (HTTP), which will give you data for both Greenland and Antarctica ice as well as sea level change. All three sets can be used for linear regression or multiple regression predicting sea level change based on both ice mass changes (recall that melting sea ice doesn’t raise sea levels but land ice does).

A Record Warm March

A NOAA news report, Global Climate Report – March 2017 Monthly temperature anomalies versus El Niño, provides us with the graph here of monthly temperature colored coded by ENSO events. The report notes that

March 2017 marks the first time since April 2016 that the global land and ocean temperature departure from average is greater than 1.0°C (1.8°F).

This is also the first time a monthly temperature departure from average surpasses 1.0°C (1.8°F) in the absence of an El Niño episode in the tropical Pacific Ocean.

March 2017 tied with January 2016 as the fifth highest monthly global land and ocean temperature departure from average on record (1,647 monthly records).

Atmospheric CO2 growth

According to the NOAA report Carbon dioxide levels rose at record pace for 2nd straight year (graph here from their report).

“The rate of CO2 growth over the last decade is 100 to 200 times faster than what the Earth experienced during the transition from the last Ice Age,” Tans said. “This is a real shock to the atmosphere.”

Globally averaged CO2 levels passed 400 ppm in 2015 — a 43-percent increase over pre-industrial levels. In February 2017, CO2 levels at Mauna Loa had already climbed to 406.42 ppm.

NOAA provides an interactive website with data: Trends in Atmospheric Carbon Dioxide. The calculus materials page here also has Mauna Loa CO2 data and a project.

The Great Barrier Reef Under Stress

The ARC Centre of Excellence for Coral Reef Studies released the statement Two-thirds of Great Barrier Reef hit by back-to-back mass coral bleaching today (graphic here from them).

“The bleaching is caused by record-breaking temperatures driven by global warming. This year, 2017, we are seeing mass bleaching, even without the assistance of El Niño conditions.”

“Clearly the reef is struggling with multiple impacts,” explains Prof. Hughes. “Without a doubt the most pressing of these is global warming. As temperatures continue to rise the corals will experience more and more of these events: 1°C of warming so far has already caused four events in the past 19 years.”

“Ultimately, we need to cut carbon emissions, and the window to do so is rapidly closing.”

The Guardian also has a related article, Great Barrier Reef at ‘terminal stage’: scientists despair at latest coral bleaching data, and in that there are graphs that could be used in classrooms if someone wants to track down the data. There are materials on the ARC Center’s page worth exploring.

Changes in the Jet Stream

The Washington Post article, One of the most troubling ideas about climate change just found new evidence in its favor, summarizes a recent study on the possible impact to the jet stream due to climate change.

The Northern Hemisphere jet stream flows in a wavy pattern from west to east, driven by the rotation of the Earth and the difference in temperature between the equator and the North Pole. The flow is stronger when that temperature difference is large.

But when the Arctic warms up faster than the equator does — which is part of the fundamental definition of global warming, and which is already happening — the jet stream’s flow can become weakened and elongated. That’s when you can get the resultant weather extremes.

 

The changes in the jet stream’s flow fixes weather patterns for a longer period of time. So, for better or worse, patterns in weather persist longer.

The study, its authors write, “adds to the weight of evidence for a human influence on the occurrence of devastating events such as the 2003 European heat wave, the 2010 Pakistan flood and Russian heat wave, the 2011 Texas heat wave and recent floods in Europe.”

What goes unmentioned in the article is that devastating weather events disproportionately impact the poor. The original paper, Influence of Anthropogenic Climate Change on Planetary Wave Resonance and Extreme Weather Events, has all the technical details.

 

Proposed Cuts to Science Budgets

This blog is generally not meant to be explicitly political, although there is no doubt that the posts and data provided here are minimally implicitly political. There will be occasions where a more explicitly political post will appear and this is one of these times. The NYT has an article on the proposed presidential budget and how it will impact science research: Scientists Bristle at Trump Budget’s Cuts to Research.

Still, the extent of the cuts in the proposed budget unveiled early Thursday shocked scientists, researchers and program administrators. The reductions include $5.8 billion, or 18 percent, from the National Institutes of Health, which fund thousands of researchers working on cancer and other diseases, and $900 million, or a little less than 20 percent, from the Department of Energy’s Office of Science, which funds the national laboratories, considered among the crown jewels of basic research in the world.

“As to climate change, I think the president was fairly straightforward: We’re not spending money on that anymore,” Mick Mulvaney, the director of the Office of Management and Budget, said at a White House briefing on Thursday. “We consider that to be a waste of your money to go out and do that.”