Hannah Hoag

Category: environment

  • Regime Change: Q&A with John Smol

    Nature

    A freshwater ecologist at Queen’s University in Kingston, Ontario, Canada, Smol studies lake sediments to understand climatic and environmental change. Nature Outlook asks him to share his experience.

    What can we learn from lake sediments?
    One of the biggest challenges in environmental science is the lack of long-term data, so we have to use indirect proxies. All over the planet, lakes act as passive samplers of the environment, recording information 24 hours a day. They contain biological, chemical and physical information. The deeper you go in the sediment, the older it gets. Typically, in North America you can go back 12,000 years to the last Ice Age. In ponds near the Arctic Ocean, it’s closer to 5,000 years, because before that those areas were below sea level. We focus on the changes that have occurred in the past few hundred years and compare them with the long-term record. So we can ask: is there anything peculiar going on now, or is this just part of a long-term cycle?

    What have these remote ponds told us about climate change?

    We chose shallow ponds because they would be the most sensitive. They’re the bellwethers. The palaeo-data show that some very striking ecological changes started happening since the 1800s. The most plausible interpretation is that it was climate change and that it was human related. This conclusion was very controversial when we published it in 1994 (ref.1).

    We started going to these ponds on Cape Herschel in far northern Canada in 1983. We were going up every two or three years, and we could see they were getting shallower. We thought they could eventually disappear, but none of us thought it could happen in our lifetime. By 2006, many of the ponds had gone dry. It was stunning. We wondered if it was a one-off event, but we checked the 2005 data from the probes that we had left in some of the ponds in 2004 and saw that they were dry even then. We could tell that the ponds were evaporating, not draining, because the water’s conductivity — which is proportional to the concentration of dissolved ions — had steadily been increasing. Nothing like this had ever happened before, although the drying trend has occurred since. We called it crossing the final ecological threshold.

    Keep reading this article in Nature. 

  • Acidic oceans threaten fish

    Acidic oceans threaten fish

    Stocks could suffer as seas soak up more carbon dioxide. 

    Ocean acidification looks likely to damage crucial fish stocks. Two studies published today in Nature Climate Change reveal that high carbon dioxide concentrations can cause death and organ damage in very young fish.

    The work challenges the belief that fish, unlike organisms with shells or exoskeletons made of calcium carbonate, will be safe as marine CO2 levels rise.

    Fish could be most susceptible to carbon dioxide when in the egg, or just hatched.

    Oceans act like carbon sponges, drawing CO2 from the atmosphere into the water. As the CO2 mixes with the water, it forms carbonic acid, making the water more acidic. The drop in pH removes calcite and aragonite — carbonate minerals essential for skeleton and shell formation — from the marine environment.

    This can mean that corals, algae, shellfish and molluscs have difficulty forming skeletons and shells or that their shells become pitted and dissolve.

    Flawed belief? 

    At present, atmospheric CO2 levels exceed 380 parts per million and are expected to climb throughout the century to approximately 800 p.p.m. if emissions are not kept in check. And the oceans are expected to continue to sop up the gas, dropping ocean pH by 0.4 units to about 7.7 by 2100 [2].

    However, many scientists have suggested that acidification wouldn’t be problematic for marine fish because they don’t have exoskeletons and because as adults they possess mechanisms that allow them to tolerate high concentrations of CO2.

    But a handful of studies have shown that increased CO2 levels can wreck the sense of smell of orange clown fish larvae and increase the size of the otolith — a bony organ akin to the human inner ear — in white sea bass larvae.

    Continue reading this story at Nature.

    Image: Hannes Baumann

  • Frozen Assets

    Frozen Assets

    Maclean’s

    Ice cores tell the history of Canada’s climate, but now the government doesn’t want them anymore. (more…)

  • Canada’s ice cores seek new home

    Confusion over fate of valuable climate record chills researchers.

    An unusual ‘help wanted’ advertisement arrived in the inboxes of Canadian scientists last week. The e-mail asked the research community to provide new homes for an impressive archive of ice cores representing 40 years of research by government scientists in the Canadian Arctic.

    The note was sent out by Christian Zdanowicz, a glaciologist at the Geological Survey of Canada (GSC) in Ottawa. He claimed that the collection faced destruction owing to budget cuts at Natural Resources Canada (NRCan), the government department that runs the survey, and a “radical downsizing” of the Ice Core Research Laboratory. The e-mail pressed scientists at universities and other institutions to take in the ice cores before they were left to melt.

    But David Scott, director of the GSC’s northern Canada division, denies this and says that there have been no budget cuts at GSC. He says that GSC management did not approve the letter, and it contains a number of factual errors. “There is no shutdown of the ice-core facility being contemplated. We’re not actively dispersing the collection,” he says. “Nothing that meets the criterion of having scientific value would be destroyed.”

    >> Continue reading at Nature.com

    This story was posted on ScientificAmerican.com, and mentioned on Mother Jones‘ Blue Marble blog

     

     

     

     

     

  • Mixed Reviews for Quebec’s Plan Nord

    Mixed Reviews for Quebec’s Plan Nord

    The government of Quebec (Canada) has launched its multibillion-dollar Plan Nord, which will open the vast northern reaches of the province to mining and energy development–and protect 50% of the territory from economic development.

    The 1.2-million-square-kilometre region—twice the size of France—is known for its wild rivers, biodiversity, diverse ecosystems and a large swath (about 20%) of Canada’s boreal forest. Boreal forest covers more than 25% of Quebec. More than 120,000 people, including 33,000 aboriginals also live in the region.

    Quebec Premier Jean Charest said yesterday the government will invest CDN$80 billion into mining, forestry, transportation, energy development and tourism over the next 25 years.

    The environmental aspects of the plan include the promise to set aside 600,000 square kilometres of the region to protect the environment and preserve biodiversity. By 2016, the government will have established several provincial parks, completed a survey of northern Quebec’s biodiversity, protected over 31,000 square kilometres of land, and adopted mitigation or restoration plans for each development project.

    By protecting half of the forest, the Quebec government will keep more than 13.8 billion tons of CO2 sequestered—equivalent to about 70 years of industrial carbon dioxide emissions in Canada (Canadian Boreal Initiative, 2009 release).

    The Plan Nord is getting mixed reviews from environmental groups. The Canadian Boreal Initiative, affiliated with the Pew Environment Group’s International Boreal Conservation Campaign applauded the sustainable development measures included within the plan (release). But others, including Greenpeace and Nature Quebec, said they could not endorse the plan as presented. The coalition of groups told the Globe and Mail the plan was “an attempt to regulate a mining boom rather than the expression of an authentic vision for the north.” They called for, among other things, an evaluation of the global environmental impacts of northern development.

    From the Nature News blog.

    Image: MRNF, Gouvernement du Quebec