Stories tagged Nitrogen

You know you want to know!

First, check out the Household Flux Calculator, and discover your flux score. With your curiosity piqued, keep going and find out how your household activities influence the cycles of carbon, nitrogen, and phosphorus.

Although households are known to influence the energy budgets of cities and countries, few studies have looked at their contribution to environmental pollution. The University's Twin Cities Household Ecosystem Project involves a survey of 3,100 urban and suburban households in Ramsey and Anoka counties and their household emissions. The study centers on a range of behaviors, including household energy use, food choices, vehicle use, air travel habits, pet ownership and lawn care practices. University scientists Lawrence Baker, Sarah Hobbie and Kristen Nelson will discuss the surprising results of this groundbreaking research.

And, yes, they'll answer the question, if you ask them nicely.

Households and Urban Pollution
Tuesday, January 18, 7 p.m. Doors open at 6 p.m.
Bryant-Lake Bowl, Minneapolis
Cost: $5-$12. Tickets available at the door and online at Bryant-Lake Bowl.
Call 612-825-8949 for reservations.

Oct
13
2010

Happy as a whale in: ... in whatever.
Happy as a whale in: ... in whatever.Courtesy Ineuw
We love whale poop around here. Love it love it love it. Can’t get enough. It’s fortunate for us that whales poop so much—if you were to get the planet’s daily supply of whale poop in one place, and if you were also in that place, you would suffocate. It’d be awful.

The reason we love whale poop so much is because of its role in what Elton John and I like to call “the circle of life.”

We’ve already discussed how sperm whales have a net negative contribution to atmospheric CO2, because of all the iron in their poop. (The iron rich waste feeds tiny sea creatures, which, in turn, suck up CO2.)

It turns out that whales and their poop are also vital for the nitrogen cycle. Nitrogen is a vital nutrient for ocean life. While some parts of the ocean have too much nitrogen—extra nitrogen from fertilizers washes out through rivers, causing algae to grow out of control and create a dead zone—other areas contain a very small amount nitrogen, and local ecosystem productivity is limited by nitrogen availability.

So what brings more nitrogen to these nitrogen-poor areas? Microorganisms and fish bring it from other parts of the ocean, and release it by dying or going to the bathroom. But, also… whales bring it. Whales bring it by the crapload.

Whales, it turns out, probably play a very heavy role in the nitrogen cycle. And because the nitrogen feeds tiny ocean creatures, and those tiny ocean creatures feed larger ocean creatures, and on and on until we get to fish, more whales (and whale poop) means more fish. And we (humans) love fish.

Commercial whaling over the last several hundred years reduced global whale population to a small fraction of what it once was, but even at their current numbers whales contribute significantly to nitrogen levels in some areas. More whales, the authors of a recent whale poop study say, could help offset the damage humans have done to the oceans and ocean fisheries, while relaxing restrictions on whaling could have much further reaching ramifications than we might expect.

See? Whale poop is the best! (Whales too, I guess.)

We've talked about "planetary boundaries" on Science Buzz before—natural thresholds past which life gets tricky. There's a new study out on one of those boundary areas: the nitrogen cycle.

The article behind the link talks about why nitrogen is important, how it's dangerous, and what we can do to let natural self-correcting systems kick in for the nitrogen cycle.

Aug
06
2010

The air around us is not as clean as it could be. Scientists are looking for ways to remove toxins, like nitrogen oxide, from the air we breathe. One of the main sources of nitrogen oxide is automobile traffic. A solution to this problem might be found under our very wheels.
Pavers: Pavers, like these, coated with nanoscale particles of Ti02 can help clean the air.
Pavers: Pavers, like these, coated with nanoscale particles of Ti02 can help clean the air.Courtesy Pacificpavingstone

How does it work? Concrete pavers are coated with nanoscale particles of titanium dioxide (TiO2). Kicked off with the energy from sunlight, TiO2 converts nasties, like nitrogen oxides, into much less harmful nitrates via a chemical reaction. Nanoscale particles have lots of surface area where a chemical reaction can occur. Also good? It seems that this coating remains stable. Tests conducted almost two years later show no change.

My favorite part of this article...they did not stop there. They asked "What about the nitrates we are introducing into the system? Where's that going?" Rain sweeps the nitrates off the road, into ditches and on to waste water treatment facilities.

Apr
16
2010

Is this house a biogeochemical hotspot?
Is this house a biogeochemical hotspot?Courtesy monkeyc.net
To ecologists who study the environment, cities and suburbs are fascinating places. For one thing, they're full of people, and people take-up space, consume materials and energy, and create waste every single day. When people do this together in concentrated areas like cities and suburbs, they create what scientists call "biogeochemical hotspots" - places where chemical and energy reaction rates are much faster than in surrounding areas.

Individual houses are also hotspots. A group of scientists at the University of Minnesota, led by researchers Sarah Hobbie and Kristen Nelson, are trying to understand more about urban ecosystems and how chemicals and energy cycle through different people's homes.

They've begun to study a small group of people whose homes are here in Minnesota - asking them questions about their behavior and taking surveys and samples on their property.

What they've found might surprise a few people. It turns out that not everyone uses energy and chemicals the same way. Small numbers of individuals and families consume and waste much more than others - creating a bigger footprint in their ecosystem.

So who are these disproportionate polluters? There is a lot that scientists still don't know, especially about why people make the choices they do, but one thing seems to be clear - generally speaking, the more money that a family makes, the bigger their ecological footprint.

These bigger impacts come from a few behaviors that wealthier Americans tend to exhibit more than their less-wealthy counterparts. Flying in airplanes, buying a much larger home, having more pets and driving a car more often all contribute to a family's impact on their ecosystem.

While studying the role individuals play in urban ecosystems, another thing these scientists found to be true was that small individual actions - for example, turning down the thermostat in the winter just a few degrees, or using less chemicals on lawns, did have a significant impact on the environment.

You can see a recording of two of the researchers involved this study .