African Diet, Jobs Will Be Hit Hard by Climate Change

National Geographic - Tracie McMillan*

African farmers will lose much of their crops to global warming in the coming decades. Photograph by James L. Stanfield, NG Creative

Corn, beans and bananas could start to disappear from sub-Saharan Africa—where those crops are among the most important for local consumption—by century's end. The culprit? Climate change.
A new study of staple crops in that region, published Monday in the journal Nature Climate Change, predicts that by 2025, 30 percent of land in the region currently cultivated for bananas, primarily in West Africa, will become unsuitable for the crop, say researchers with the Consultative Group for International Agricultural Research. Bananas are significant for local consumption, say researchers.
Meanwhile, 60 percent of bean agriculture will cease to be productive by 2050, as will 41 percent of land currently dedicated to maize, the study says. Those crops are incredibly dominant in the sub-Saharan diet, featured in dishes ranging from githeri, a flavorful corn and bean stew, to ugali, a mush made of cornmeal and water.
Five other prominent crops—millet, sorghum, cassava, groundnut and yams—are expected to maintain production levels through 2100. Crops grown primarily for export, such as coffee, cocoa, and tea, were not studied.
The research marks the first quantification of crop "transformation"—planning for the inevitable decline of certain crops—in Africa, said lead researcher Julian Ramirez-Villegas, a research fellow at the University of Leeds. In addition to projecting crop viability through the century, researchers also describe a three three-stage process for managing the shift.
The research has serious implications for sub-Saharan Africa, said Ramirez-Villegas. Agriculture contributes nearly two-thirds of all employment in that region and food insecurity rates there are already the highest in the world. "It's kind of a combination of a lot of different vulnerabilities coalescing at the same time," said Ramirez-Villegas. "And, at the same time, agriculture is a key sector for africanAfrican livelihoods."
As those crops fail, farmers will need to adjust, either switching crops or, in extreme cases, give up agriculture altogether. And if crop outputs diminish, that could pressure sub-Saharan Africa, already a net importer of food, to rely even more on other countries to stay fed.
Much of the land being threatened by climate change will need to be "transitioned," said Ramirez-Villegas, and put to other use. While maize, which only became a staple in Africa over the last century, may no longer be as viable, it could be replaced with millet and sorghum, which are native to Africa (and tolerant of heat and drought), and would likely thrive. The other alternative, say researchers, could be swapping crop agriculture for another kind of farming, such as livestock. Kenyan farmers, for example, began exploring camel husbandry as a replacement for cattle—or leaving farming altogether.
Those changes would have a direct impact on the food security and diet of residents in sub-Saharan Africa. With the exception of bananas, the crops in the study are all grown primarily for domestic consumption.
"Most of the production [studied here] is consumed locally and sold in local markets, or produced for subsistence," said Villegas-Ramirez. "But African countries are also importing significant amounts of food."
Researchers plan to expand their research to explore additional substitute crops, said Villegas-Ramirez, as well as project the direct impact of changes in agriculture on the diet available to residents.

*Tracie McMillan is an independent journalist covering food and equity. She is the author of the New York Times bestseller, The American Way of Eating, and is a senior fellow at the Schuster Institute for Investigative Journalism at Brandeis University.

Links

• In a Warmer World, There May Be Fewer Fruits and Vegetables

The More We Learn About Antarctica’s Past, The Scarier The Present Looks

Washington Post - Chris Mooney

A zodiac carrying a team of international scientists heads to Chile's station Bernardo O'Higgins in Antarctica in January 2015. (Natacha Pisarenko/AP)

For the second time in a month, leading scientists have closely tied the ancient history of the vast Antarctic ice sheet to a key planetary parameter that humans are now controlling — the amount of carbon dioxide in the atmosphere.
Last month, new research showed that during the Miocene era, some 14 to 23 million years ago, Antarctica gave up huge volumes of ice, equivalent to tens of meters of sea level rise, when levels of carbon dioxide in the atmosphere are thought to have been around 500 parts per million. We're at a little over 400 parts per million now.
And now, new research in the journal Science goes back even farther, to the ancient era when the ice sheet's growth is believed to have originally begun, some 34 million years ago during a time period known as the Eocene-Oligocene boundary. And it finds that at this time, too, a fall in atmospheric carbon dioxide levels appears to have been involved in allowing glaciation and ice sheet growth.
"Before 33.6 million years ago, there was no ice, and CO2 was above 750, was above the threshold," said Simone Galeotti, lead author of the new study by a large international collaboration of authors, and a researcher at the Università degli Studi di Urbino in Italy. But then came a transitional period with lower carbon dioxide and a variable ice sheet — and then, 32.8 million years ago, carbon dioxide levels dipped below 600 parts per million, and the Antarctic ice sheet greatly expanded.
The research is based on a nearly kilometer-long core of deep ocean sediment taken from the western part of the Ross Sea, not far from the United States' McMurdo station. The distribution of key bits of rock in different layers of the core, said Galeotti, suggests that it wasn't until 32.8 million years ago, emerging from the warmth of the period known as the Eocene, that icebergs were breaking off of an ice sheet that stretched all the way to the Antarctic coast. These icebergs floated out into the sea and melted, and rocks or "clasts" carried in the ice fell to the sea floor, leaving clues that modern geologists can read.
"We see ice-rafted clasts reaching the drilling site only at 32.8 million years. Which says that before that time, the ice sheet was not fully developed," Galeotti said.
Before this period, in the Eocene climate — typically referred to as a "hothouse" world and occurring between 55.8 million and about 34 million years ago — Antarctica actually featured trees and vegetation. The Arctic was also extremely warm back then — alligators swam there.
The planet at the time did not have land-based ice and was far hotter than now, with much higher seas overall and much higher carbon dioxide levels in the atmosphere. This changed in the transition from the Eocene to the Oligocene, which ushered in a cooling that closely tracked declining levels of carbon dioxide in the atmosphere — although it was also buffeted, over long time periods, by tweaks and changes to the Earth's orbit.
"This is one of the biggest climate changes that the planet has seen in the last 50 million years, when Antarctica went from being forested and vegetated, to really … it became glaciated at this Eocene-Oligocene boundary," said Rob DeConto, one of the study's co-authors and a geoscientist at the University of Massachusetts, Amherst.
In this context, the new research further tunes our understanding of how much carbon dioxide allows the ice sheet to grow or causes it to melt. "The ice sheet was particularly vulnerable between 33.6 and 32.8 million years ago, with the CO2 level between 750 and 600," Galeotti said.
That might still sound pretty far off from where we are now, but here's the catch. When the Antarctic ice sheet initially formed, scientists don't believe that it had one of its most distinctive current features — large portions, particularly in West Antarctica but also in key regions of East Antarctica, where ice is grounded deep below sea level.
That's because after the ice sheet formed, its huge and crushing weight deformed the land surface beneath it over time, allowing these particular areas to become submerged. And these regions, where ice is not on land but rather lies on a foundation deep beneath the sea, are expected to be vulnerable well before 600 parts per million of carbon dioxide levels are reached, Galeotti said.
"The part of the ice sheet now sitting below sea level is making this ice sheet even more vulnerable than the Eocene-Oligocene boundary ice sheet, because there are different mechanisms for melting," said Galeotti. Specifically, warm ocean water, or ocean currents, now have access to the ice sheet, which was not the case when it was fully on land.
Such differences between now and 34 million years ago, however, also signal a major caveat when drawing inferences linking Antarctica's ancient past to the present. After all, other processes than those associated with carbon dioxide may have further enhanced the growth of the Antarctic ice sheet back then — processes that are either no longer operative today or not really relevant because of the speed at which we are now changing the planet.

The Potsdam Institute for Climate Impact Research shows what would happen if glaciers in West Antarctica melted. (Potsdam Institute for Climate Impact Research)

For instance, in an accompanying commentary in Science, Carolyn Lear of Cardiff University and Dan Lunt of the University of Bristol note that there have long been arguments that the tectonic widening of the Drake Passage, between South America and Antarctica, was involved in the original development of the Antarctic ice sheet, by allowing the continent to become more isolated. They now argue that this widening, by enabling the Antarctic circumpolar current and better connecting the Atlantic and the Pacific, may have also acted to help bury carbon dioxide in the ocean — which, in turn, would have simultaneously enhanced ice sheet growth.
We may be driving planetary carbon dioxide levels right now, but plate-tectonics is another matter — so there are clearly aspects of this story from the past that are not as relevant to the present.
And there's another caveat — studies of how the ice sheet changed over millions of years may or may not be relevant to the timescales that today's humans care about. What we really want to know is whether Antarctica is going to give up a major amount of ice in the next 100 years or  more. You can't directly answer that question based on the new study.
Still, the research suggests that the Antarctic ice sheet can do things that our computer simulations, alone, may not capture, said Thomas Wagner, program scientist for the cryosphere at NASA, who is familiar with the new study.
"We run all these ice sheet models for things like the IPCC report and sea level rise projections. And they're great, they represent an amazing integration of mathematics, cutting edge computing, and integration of disparate fields like ice physics and oceanography," Wagner said.
"But we also know from the geologic record that the big ice sheets undergo major, rapid changes from time to time that are difficult to capture in our models but can cause sea levels to rise very rapidly — as in more than five feet in 100 years. Results like this one — connecting Antarctica to atmospheric CO2 levels not far off from where we are now — are important because they tell us what the ice wants to do. It helps guide future modeling, gives us a new way to frame our current studies, and provides bounds for hazard assessment for sea level," he said.
As is often the case with major Antarctic research, the new study is also an example of international collaboration. The scientists involved are from Italy, the United States, New Zealand, the Netherlands and the United Kingdom. The ideas were hatched when the researchers came together for a summer program in paleoclimatology at Urbino in Italy, said Galeotti.
The bottom line, said DeConto, is that the new research is "just adding to the mountain of evidence that, when greenhouse gas concentrations were high in the past, climate was warmer, there was less ice" in Antarctica.  "And even in times when there were ice sheets when CO2 was higher than today, those ice sheets were variable; they grew and shrank."
The more we come to understand Antarctica's history, the more this continent, whose ice sheet is too big to even wrap our minds around, becomes relevant to our present.

Links

• This mind-boggling study shows just how massive sea level rise really is
• Antarctica could be much more vulnerable to melting than we thought
• Scientists confirm their fears about West Antarctica — that it's inherently unstable
• Scientists confirm that East Antarctica's biggest glacier is melting from below
• It's official: We can now say global warming made some weather events worse
• Next up from climate change: More polar bears on land, potentially running into humans
• Before his tragic death, nature photographer shot iconic images of climate change's threat
• China vowed to peak emissions by 2030. It could be way ahead of schedule
• What the Clinton-Sanders divide on fracking says about our energy future

CSIRO Climate Cuts 'A Catastrophic Failure Of Public Policy', Senate Told

The Guardian - Michael Slezak

US and Australian climate research experts say staff cuts will make it hard for Australia to achieve best policy results in international negotiations

The Senate committee was told the staff cuts at the CSIRO would be wasting millions of dollars of investment in expertise. Photograph: Alan Porritt/AAP

Cuts to climate research at Australia's science agency, CSIRO, are a "catastrophic failure of public policy" that will damage the UN's climate change work and will hinder Australia's ability to represent its self-interest at international climate change negotiations, the Australian Senate has heard.
The UN's Intergovernmental Panel on Climate Change produces the world's most authoritative statements on the nature of climate change, its impacts, and how to adapt to and mitigate it. To do that, it combines a suite of climate models.
That process would be hampered by the CSIRO's recent decision to shift resources away from climate modelling and monitoring, Karl Taylor, of the program for climate model diagnosis and intercomparison at the Lawrence Livermore National Laboratory in the US, told a Senate committee hearing on Friday.
"The CSIRO model ... has been involved in all of these international modelling activities that have contributed immensely to the IPCC's understanding of climate change, and that would be cut dramatically," he said.
The cuts would also make it hard for the government to achieve the best results for Australia at international negotiations.
"When the government prepares to go to the conferences annually where they discuss climate change policy – and negotiate, as they did in Paris this last year – they need advice," he said.
"And I think cutting the efforts at the CSIRO will undermine the government's ability to really represent its own self-interest at those negotiations because they would lose the advice of the experts there."
Paul Durack, also from the Lawrence Livermore National Laboratory, said it did not make sense to cut from work on understanding climate change in order to shift towards work on adaptation and mitigation.
He said the IPCC process demonstrated the problem with that logic. In that process, the IPCC publishes three chapters or "working groups". The first is on the physical basis of climate change. The other two, which focus on the impacts and how to mitigate and adapt to them, are published later, and rely on the information published in the first chapter.
"The way it occurs very much highlights the dependence between these different working groups and the requirement to actually have physical information about the climate system," Durack said. "You can't do these things independently and they're very much dependent on one another."
David Karoly, from the University of Melbourne, told the committee the decision would be wasting millions of dollars of investment in expertise.
"My estimate is it is of the order of 1,000 person years of experience or more," he said. "And that's at least $100m of investment. And it appears to be thrown away or put into a rubbish bin."
Snow Barlow, from the University of Melbourne, works on climate change adaptation and mitigation. He told the committee it was a mistake to take resources away from monitoring and modelling climate change to focus on adaptation and mitigation: "It's a catastrophic failure in public policy."
In a hearing on Wednesday, the same committee heard the CSIRO's international reputation had already been "trashed" by the announced cuts, and a new science body was needed.
Earlier, a report by the Climate Council said the cuts would breach Australia's obligations under the recent Paris climate change agreement.
The CSIRO's chief executive, Larry Marshall, said in a radio interview last month the reaction to his planned cuts was more like religion than science, and compared climate science with the oil lobby in the 1970s. He later apologised for the reference to religion.

Links

• CSIRO's global reputation 'trashed' and new science body needed, Senate told
• CSIRO chief confirms climate modelling and monitoring jobs to be halved
• Australia's chief scientist says he was not warned about CSIRO climate cuts
• CSIRO climate cuts attack a national treasure when we need it most
• CSIRO climate cuts will cost Australia dear, world scientists warn government
• Senior CSIRO scientist derides chief executive's claim climate change is 'answered'
• After climate cuts at CSIRO, who should we ask about global warming impacts on Australia? Netflix?
• CSIRO chief says row over climate science cuts 'more like religion than science'