Sunday, March 30, 2008

The silly season (in climate)

It is quite easy to get all self-righteous about the Democratic nomination process descending into an ugly, childish battle, the sort of thing usually reserved for the general elections or WWE Raw. It is not clear who is actually doing battle – the candidates, the advisors or the bobble-heads on cable – and it is not clear that most people actually care. It is all about the spectacle, the appearance of a dispute, the air of scandal. The facts, the issues, are secondary, probably even tertiary.

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Tuesday, March 18, 2008

Is energy expensive?

With the price of oil surging well past US$100, Michael Tobis reminds us that energy is actually quite cheap:

A hundred dollars a barrel. A barrel! Energy is unbelievably cheap.

That's about six million BTUs. One point seven megawatt hours. With that $100 barrel you can power your laptop for two years. You can ship hundreds of pounds of bananas from Guatemala. You can microwave a hundred and two thousand cups of tea to steaming warmth. You can power the digital clock on your microwave for seven million years!

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Monday, March 17, 2008

Hypoxic zones around the world

The World Resources Institute and scientist Bob Diaz of Virginia Marine Institute have compiled a new map of the world's coastal hypoxia zones like the famous Gulf of Mexico "Dead Zone" we discuss in the recent PNAS paper on nitrogen pollution and corn production for ethanol. The new map includes 169 documented hypoxic areas, 233 are areas of concern and 13 areas in recovery.

Bottom-water hypoxia can develop when high input of nutrients like nitrogen promote the excessive algae growth. When algae eventually dies and sinks to the bottom, it decomposes, and that process depletes oxygen from the water.

It is worth noting hypoxia will not arise anywhere simply because nutrients are added. To get things started, you still need to feed the algae, and nutrient pollution does the trick. But certain
coastal areas are more naturally prone to hypoxia.

If, for example, the water column is highly "stratified", by that I mean less dense water lying above more dense water there is little mixing between the surface and the bottom waters (think of making a simple oil and vinegar salad dressing). It is then difficult for oxygen from the air to diffuse to the bottom and replace the oxygen consumed by decomposition.

The outlet of big rivers like the Mississippi can be ideal for hypoxia development because the fresh and therefore lighter water introduced by the river creates a stratified water column. That explains some of the year-to-year dynamics of the hypoxic zones like the Gulf Dead Zone. First, hypoxia development can be much worse in a wet or flood year because of the addition of more nutrients and the increased stratification. Second, if a hurricane blows through the Gulf, it encourages mixing just like you do by shaking that bottle of salad dressing, and can break-up the Dead Zone.

The new map supposedly includes only human-driven cases of hypoxia. Which raise the question, what is the cause of the zone between very sparsely populated Somerset and Cornwallis Islands in Nunavut, in the Canadian Arctic? If you have an answer, let me know.

Monday, March 10, 2008

Corn ethanol production will worsen the Dead Zone

A new paper by my colleague Chris Kucharik and I looks at the new US Energy Policy, will calls for growing more corn to produce ethanol, will affect the "Dead Zone" in the Gulf of Mexico. For a quick summary, see Reuters, the CBC or AFP (or my 15 Minuten ruhm on German ARD). Wired and Scientific American go into more detail.

The Mississippi dumps a massive amount of nitrogen, largely in the form of the soluble ion nitrate, into the Gulf each spring. It promotes the growth of a lot of algae, which eventually sinks to the bottom and decomposes. This consumes much of the oxygen in the bottom waters, making life tough for bottom-dwelling fish and creatures like shrimp. The Dead Zone has reached over 20,000 km2 in recent years.

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Friday, March 07, 2008

How times have changed

And, no, I'm not talking about Canadian politics and government becoming so feckless and uninspiring that we must stoop to meddling in the US primary campaign for attention.

This can be found in the 2008 Canadian federal budget under the heading "Ensuring a Cleaner, Healthier Environment":

Investing $300 million to support nuclear energy