Discovery News: Environmental

Geiger Countertop

According to a New York Times article, your granite countertop may be a hot commodity. Literally.

It turns out that granite countertops emit radiation including radon--the radioactive gas resulting from the breakdown product of uranium within. The vast majority of granite countertops emit far less than the background radiation we're exposed to all the time.

But, a few countertops have been found to have relatively high levels of radiation--some more than 100 times background. (Even countertops emitting above background are unlikely to cause cancer, according to the Times.)

What struck me about this story was not the possible slight increased cancer risk from a granite countertop, but the following:

"The E.P.A. recommends taking action if radon gas levels in the home exceeds 4 picocuries per liter of air (a measure of radioactive emission); about the same risk for cancer as smoking a half a pack of cigarettes per day."

The recommended action level equates to 10 cigarettes per day? Given how widespread smoking bans are these days, I'm surprised there isn't more of a push to keep our basements from being the radon equivalent of a restaurant smoking section. Then again, who said these processes were rational?

P.S. I noticed that Larry O'Hanlon also posted about this article at his Earth Impacts blog. Check it out.

(Image: Flickr user Kyknoord, some rights reserved.)

Nuclear Cooling

Today I wrote a story about how wildfire smoke acts to cool the Arctic by reflecting light back into space before it hits the surface.

I spoke with Alan Robock at Rutgers University who said, "I worry much more about nuclear weapons than I do about climate change in its effect on our climate."

Nuclear weapons could create plenty of cooling smoke, Robock says, even if used on a relatively small scale.

"We've calculated how much smoke you would get from a 'tiny' war between India and Pakistan, each using 50 Hiroshima-sized bombs," he said. "Even that would produce climate change to temperatures colder than in the Little Ice Age."

Robock's study found that the associated drop in agricultural productivity from global cooling could be enough to lead to famine. Other studies have suggested that a full-scale nuclear war could result in death of a majority of the world's population from such indirect causes.

I'm all for avoiding climate impacts from CO2 emissions and from nuclear fallout. Everybody with me?

(Photo courtesy of National Nuclear Security Administration / Nevada Site Office)

Shuffling Species

As the climate warms, many species may no longer be comfy in their habitats and become better suited to survival at higher latitudes or higher elevations where they can escape the heat. But how is a tree species that takes decades to reproduce going to migrate fast enough to keep pace with a rapidly changing climate? What if a major city lies between a critter's old habitat and where it needs to go to survive?

We might help. That's the idea behind "assisted colonization"--deliberately moving plants or animals from places where they're doomed to places where they might survive in the future. In today's issue of Science, a group of researchers published an article saying this is an approach we should take seriously. Read an article about it at Discovery News.

It's a horrifying prospect to some conservation biologists. They point to the long list of species introduced into new habitats by humans (like moving cane toads to Australia) that have gone terribly wrong. The authors of the new report agree that some introductions would be risky and should be avoided: moving polar bears from the Arctic to Antarctica would introduce a predator of penguins and seals and likely decimate those populations.

But other introductions seem less likely to cause a disruption. Most would be regional moves, not inter-continental. The authors point out that staghorn corals currently live over a range of latitudes and that those at low latitudes can tolerate higher temperatures than the ones further from the equator. Moving low-latitude coral into higher latitudes where cold-adapted corals are already dying off is unlikely to cause a problem, the authors argue.

The researchers discuss assisted colonization as a way to save species from extinction, but there might be other motivations.

For instance, here in Minnesota, we are at the southern tip of the spruce-fir forest range, which is likely to retreat into Canada in a warming climate, and our deciduous forests face threats, too. But having forests in the state is a big part of its identity. Can we be happy knowing that the forests exist to the north and learn to live without them here? Or, should we bring in trees from further south that will thrive in our new climate and keep us under a forest canopy?

It's not just a psychological issue: forests contribute to our industrial and recreational economy, so people may be reluctant to let the woods give way to savanna. Check out an earlier post about a conference here where they discussed the topic.

What do you think? Is this a good idea? When would you be willing to give a species a helping hand? Or, should we let nature take its course... whatever that means in today's world?

(Image: Flickr user *Micky, some rights reserved)

A Test

Here's an awareness test to try for fun. You can check out the home site here. If you're interested in the subject, here's a related post.

More Math at $4 a Gallon

I wrote a couple of weeks ago about one way that $4 a gallon gasoline might get us looking at things differently.

It is interesting to see stories emerging about other ways that fuel at $4 a gallon is causing changes.

First, Reuters had a story late last week about how home buyers are abandoning the 'burbs in favor of cities, partly driven by the higher fuel prices. The article mentions a survey of realtors, 80 percent of whom reported that higher fuel costs are making buyers more interested in living in cities.

The New York Times ran a story a couple of weeks ago with a similar message. It says:

In 2003, the average suburban household spent $1,422 a year on gasoline, according to the Bureau of Labor Statistics. By April of this year -- when gas prices were about $3.60 a gallon-- the same household was spending $3,196 a year, more than doubling consumption in dollar terms in less than five years.

Meanwhile high oil prices effect more than just fuel. Petroleum provides the raw materials for making plastics, paints, adhesives, soaps, fibers, pharmaceuticals and more. Just as people are looking for alternatives to using petroleum for fuel, others are trying to obtain the carbon molecules necessary to make this array of products from renewable sources.

Plastic made from corn is one example, and DuPont is making a fiber that comes partly from corn that it is using in carpets.

Of course, the expense of these alternative products has been an obstacle, because commodity chemicals derived from oil have been cheap, cheap relative to developing new, bio-based materials. But, as a Cargill executive told me when I spoke with him more than a year ago, "When you have 75 dollar a barrel oil, a lot of things can happen."

That threshold seems a quaint memory now, and the chemical industry is feeling the heat. Dow announced price hikes of up to 25 percent on commodity chemicals a couple of weeks back.

So, by the executive's estimation, bio-based processes ought to be looking pretty good. And, one researcher told me, because the amount of carbon needed for chemicals is just a teeny trickle compared with what's needed for fuels, sending some biomass to chemical processes to make plastics and other non-fuel applications should not create the competition for food that we're seeing with corn-derived ethanol and other biofuels.

(Image: Flickr user KB35, some rights reserved.)

Humpback Wisdom

Check out today's story at Discovery News explaining how seemingly odd bumps across the front of humpback whale fins allow the whales to make the tight turns necessary to surround their herring prey before rising from beneath, mouths agape, to swallow as many as they can.

I was amazed to learn that the whales encircle the fish and release air bubbles that act like a cage the fish won't cross before moving in for the kill.

Above is a great video showing the hunt.

Also, take a look at the gorgeous video on the website for WhalePower--a company that is capitalizing on these bumps in making better wind turbines and fans--to get a nice look at the fins and some lovely views of swimming whales. Guaranteed to make you feel more relaxed.

Antarctic Wildlife Feels the Heat

Today at Discovery News we reported on work by three researchers who study different aspects of the Antarctic ecosystem, and who decided to get together and tell the combined story of the changes they've seen over the last two or three decades as a result of climate change.

We thought we'd post it here so you could have your say. Do you care about what's happening in Antarctica? Are you ready to start marching for the penguins? What strikes you about the researchers' findings?

Also, stay tuned at the end of the post for some extra tidbits that didn't fit in the original story.

(Photo: Juvenile krill, Jim McClintock)

At Antarctic Peninsula, Fast Change
Jessica Marshall, Discovery News

 

July 10, 2008 -- From the tiny phytoplankton living under the ice to the penguins at the top of the food chain, the ecosystem of the Antarctic Peninsula is changing fast, driven by warming waters and a loss of sea ice.

Three researchers who have spent decades studying Antarctica's denizens paint a picture of interconnected changes at the bottom of the Earth that are changing the ecology over just decades after some 30 million years of relative isolation.

"The changes are profound," said Hugh Ducklow of the Marine Biological Research Laboratory in Woods Hole, Mass.

He and colleagues James McClintock of the University of Alabama at Birmingham and William Fraser of Polar Oceans Research Group in Sheridan, Mont. compiled their findings from studying different aspects of the Antarctic ecosystem in an article in the current issue of American Scientist.

Nowhere on Earth is climate change happening faster than on the neck of land stretching north from the Antarctic continent more than 900 miles toward South America. The average midwinter temperature on the Antarctic peninsula has increased more than 10 degrees Fahrenheit since 1950, five times the global average.

The changes the researchers see begin at the base of the food web, with phytoplankton -- tiny photosynthetic organisms that, in Antarctica, are evolved to live in the sea ice. As the extent of sea ice has decreased, so has the amount of phytoplankton.

"Sea ice is not just ice," Ducklow said. "It's a habitat for organisms."

Indeed, juvenile krill, tiny shrimplike organisms that serve as the main food source for Adélie penguins and baleen whales, graze on the phytoplankton under the sea ice.

"Juvenile forms of krill are not as strong swimmers as adults," Ducknow said "By congregating on the underside of the ice, they get a shelter from predators, and it's where the food is."

Krill have been declining for decades, the authors note, although sea ice decline may not be the only reason.

With less krill to feed on, organisms at the top of the food chain like Adélie penguins suffer. Their populations have been decreasing in the central and northern Antarctic peninsula.

The Adelie penguins also rely on the sea ice directly. In winter, they use the sea ice to get out to hotspots of food. As this shrinks, their food will be too far away to swim to.

In contrast, two related species, the gentoo and chinstrap penguins, do not rely on sea ice for winter feeding. Their populations are rising on the Peninsula.

Meanwhile, another Antarctic community is poised to change because of rising sea temperatures.

Since the Antarctic Peninsula separated from South America 25 to 35 million years ago, Antarctica has been encircled by the Antarctic Circumpolar Current, a clockwise roundabout current that holds cold water near the continent and isolates it from the rest of the ocean.

Crabs and other predators that get prey by cracking shells with strong forces were excluded from the region once the current was established, because they cannot survive at such cold temperatures.

Without such predators to guard against, animals like snails and clams in Antarctica evolved delicate, thin shells. But as the ocean warms, crab predators may move in and have defenseless prey to capitalize on. A colony of king crabs was recently found in deeper waters off the peninsula.

"It's only a matter of time before they can move up into even shallower water," said lead author McClintock, who studies Antarctica's invertebrates. "When crabs get into those communities of clams and snails and brachiopods, they are going to be history."

McClintock notes that the reproductive cycle of invertebrates is also closely tied to temperature, and warming may lead to larvae hatching out of sync with the availability of their plankton food supply.

But, he adds, kelp-like macroalgae are likely to thrive with the greater availability of sunlight thanks to reduced sea ice. And jellyfish will probably also increase in number.

What is clear is that these populations are shifting fast in relation to one another, and the ecosystem that emerges will be different from the one that has existed in isolation for millions of years.

"People say, why Antarctica? Who cares about that?" Ducklow said. "It's a canary in the coal mine. We're seeing things happen rapidly there. It's a good wakeup call for us that there is climate change, and ecosystems really are responding to it."

******************************************

Now, here's the extra bit that I'll call

Amazing Antarctic Facts

• The reason that crabs have heretofore been unable to survive in Antarctic waters is that they cannot expel magnesium from their bloodstream. Magnesium acts as a narcotic whose effect is enhanced at low temperatures. So, until now, any crabs that decided to go strolling in too-chilly waters became immobilized and died.
• Another species that is threatened by changing sea ice is the Waddell seal. Female adult seals get a private, predator-protected birthing room by using their ice-chipping teeth to scratch open a hole in the sea ice from underneath. They pop through the hole onto the surface when they're ready to pop out their young. According to McClintock, "The price they pay for these teeth is that over the years they wear down the teeth and they starve." They live about half as long as other seals, he said, but more of their young survive.
• About 70 percent of Antarctic species are found nowhere else.
• The sea ice in midwinter is about as big as the lower 48 U.S. states, but with a lot fewer Starbucks.
• Antarctic ice holds almost 2/3 of Earth's freshwater.
• Climate change has brought more snowstorms to the Peninsula. These have also harmed Adélie penguins. When it snows in spring, the nests can flood, killing eggs and hatchlings.
• If warming trends continue, the average midwinter temperature will be above freezing (for seawater) by mid-century. Sea ice will no longer form.

Smog Blog

Wildfires have been ripping through the west, and while they endanger homes and may or may not be good for the natural habitats they burn, they are definitely bad for the air quality.

The Smog Blog tracks air quality nationwide on a daily basis with satellite data, lidar, EPA pollution-monitoring networks, and more, compiled by the University of Maryland, Baltimore County Atmospheric Lidar Group. The team provides lots of maps showing clouds, smoke, particle levels, ozone levels, etc.

In recent days the emphasis has been on the wildfires in California. Plumes of smoke are easily seen from satellite images. They suggest the huge scale of the fire, but don't do justice to the havoc much closer to the ground.

Check out the maps and the air quality near you.

 

(Image: Measurements of particles < 2.5 microns shown over California. Maroon points near Auburn, Sacramento, Roseville-Rocklin and Bakersfield show hazardous levels, overlaid on true color satellite image. Image obtained from the U.S. Air Quality Smog Blog.)

Meadow Prophecy

Last week I interviewed John Harte of the University of California at Berkeley's Energy and Resources Group for the Discovery News feature I wrote on climate change.

I had interviewed him several years before, when I wrote an article about a long-term experiment he's doing in the Rocky Mountains to understand how climate change will affect ecosystems. Since 1991 he's been heating patches of the ground in a meadow in the Rocky Mountains and observing how the numbers and types of plants in the heated plots vary compared with unheated control plots.

He found that forbs, flowering plants like daisies and other wildflower-like species, were reduced by up to two-thirds in the warmed plots, while sage thrived. Soil dried out by 15-20 percent, snow melted 2 weeks earlier, and soil temperatures rose by 2 degrees Celsius.

I asked Harte what it's like to do an experiment on warming now that things are warming up in the control plots, too.

"From 2000-2005, the snowpack was very, very low," Harte said. "This led to early snow melt, and conditions in our control plots that resemble what the heated plots were subject to in the early 1990s. Sure enough, the control plots responded the same way. The carbon levels in the soil dropped."

The findings show that the heating experiments generated good predictions. "It was nature imitating science," he said.

(Image: John Harte, University of California, Berkeley)

Does a Dairy Hormone Make Milk Greener?

Green-minded eating of animal products just keeps getting trickier. A study published Monday in the Proceedings of the National Academy of Sciences says that cows given the hormone somatotropin to boost their milk production require less energy and release less methane to produce the same amount of milk as cows not given the hormone, commonly abbreviated on milk cartons as rbST.

The authors claim that 1 million cows on rbST save the greenhouse gas equivalent of taking 400,000 cars off the road, compared with the emissions from untreated cows necessary to make an equivalent amount of milk. The savings come largely because fewer cows need less food, which requires less ground to grow it on.

But Michael Hanson of the Consumers Union in New York told news outlets (here and here) that assuming  a cow making more milk can get by on the same amount of food as an untreated cow is unrealistic. Accounting for increased food needs would remove much of the gain suggested by the authors, he said.

One of the study's authors works for Monsanto, who makes rbST under the name Posilac, and another is a Monsanto consultant.

What to do? Will you dump the organic milk to save the planet or will your milk moustache remain rbST-free?

(Image: Flickr user karlfrankowski. Some rights reserved.)