Deench

Everything for Everyone

Category Archives: pollution

LA smog: more cows than cars?

Much to the chagrin of California tourism promoters, smog is likely one of the things you picture when you think about the city of Los Angeles. The haze of pollutants that often hangs over the region is more than just an eyesore; it's a source of considerable respiratory stress. And where does that air pollution come from? Smokestacks, tailpipes, and cows. You read that right—cows. In fact, a new study estimates that cows contribute at least as much as automobiles.

There are two main factors that control the formation of smog. The first is the air pollution. This includes a range of volatile organic compounds, as well as oxides of nitrogen (referred to as NOx compounds). These pollutants react in sunlight to produce the ground-level ozone that triggers asthma advisories. The second necessary condition is stagnant air. A stiff breeze moving through the city will clear away pollution before it can collect. Areas that experience smog typically have the right topographical and meteorological conditions for air masses to hang around for a while.

Read the rest of this article...

Read the comments on this post


LA smog: more cows than cars?

Much to the chagrin of California tourism promoters, smog is likely one of the things you picture when you think about the city of Los Angeles. The haze of pollutants that often hangs over the city is more than just an eyesore; it's a source of considerable respiratory stress. And where does that air pollution come from? Smokestacks, tailpipes, and cows. You read that right—cows. In fact, a new study estimates that cows contribute at least as much as automobiles.

There are two main factors that control the formation of smog. The first is the air pollution. This includes a range of volatile organic compounds, as well as oxides of nitrogen (referred to as NOx compounds. These pollutants react in sunlight to produce the ground-level ozone that triggers asthma advisories. The second necessary condition is stagnant air. A stiff breeze moving through the city will clear away pollution before it can collect. Areas that experience smog typically have the right topographical and meteorological conditions for air masses to hang around for a while.

A large portion of the small particles, or aerosols, that contribute to the haze are comprised of ammonium nitrate (NH4NO3). The nitrate comes from NOx emissions, but the ammonium mostly comes from a couple specific sources.

Read more on Ars Technica&hellip


EPA’s carbon rules to grandfather existing coal plants, limit new ones

Although the EPA has not yet made an official announcement, it is apparently ready to issue its first regulations regarding carbon dioxide emissions. The process dates back to the Clinton years, when states first asked the EPA to use the Clean Air (CAA) act to regulate greenhouse gasses as pollutants, with carbon dioxide getting extra attention due to its role in ocean acidification. After years of delay, the Supreme Court ruled that the EPA must determine whether CO2 is a pollutant according to the CAA's definition. The Bush Administration's EPA found that it was, but its findings were never made public or acted upon (they have since been obtained by the press). The Obama EPA reached a similar conclusion, but deferred acting on it, at least until now.

According to various press reports, the EPA has been briefing stakeholders on its planned regulations. They would put the limit on emissions at 1,000 pounds of carbon dioxide per megawatt-hour of electricity produced, but will only apply to new construction. A modern natural gas plant should be able to meet that limit with little difficulty. Most coal plants in existence, however, produce roughly double that amount, and will not be able to meet it without adopting some form of carbon capture and storage technology.

The regulations will send a clear signal to the market: either find a way to capture carbon cheaply, or don't build new coal capacity. Although they do very little for existing emissions directly, they're likely to have an indirect effect, since many of the oldest and least efficient plants in use burn coal at costs that are significantly higher than that of natural gas. In addition, the renewable energy mandates adopted by many states will displace some existing power sources; these old plants will again be the primary target.

Read the comments on this post


New study suggests cap-and-trade results in decreased innovation

Among those interested in addressing the problem of climate change, one of the primary debates is about the best way to induce the private sector to develop innovative technologies. Although some favor a simple carbon tax, the US' success with a cap-and-trade system has led to its use both in Europe and in regional systems within the US. A new analysis of past US programs, however, suggests that cap-and-trade hasn't quite been the success many think it is. Its rapid early gains have been followed by a period of stagnation.

The US implemented cap-and-trade systems in the 1990s as a response to the problem of acid rain. Chemicals produced by combustion of fossil fuels (primarily coal) had previously been regulated by standard environmental regulation. However, over the course of the 1990s, SO2 and NOx were both subject to a cap-and-trade system that gave industries the option of taking different approaches to the control of these emissions. All significant sources of these chemicals were given allowances targeted to keep the total emissions below levels deemed acceptable. Innovators that cut their emissions substantially could sell their allowances to sources that found it too difficult or expensive to do so.

On some levels, this was a significant success. Emissions dropped and the cost of reaching that goal turned out to be far less than many had predicted. But Berkeley's Margaret Taylor has now gone through the numbers and found data suggesting not all is as rosy as it appears.

Read the rest of this article...

Read the comments on this post


Test of 400 options shows we can save money while limiting climate change

If a group of scientists announced that reducing emissions of some pollutants would prevent global warming, it wouldn’t make headlines—we’ve been hearing that for years when the pollutant is carbon dioxide. However, if they added that those reduced emissions would also prevent millions of premature deaths per year and increase annual crop yields by tens to hundreds of millions of tons, you would probably take notice. But the part that will really blow your mind—and what might make some people reconsider their stance—is that all of this could be done at a profit.

A large group of scientists identified 14 emissions reduction measures—out of around 400 considered—that primarily reduce ozone and black carbon (BC; think soot) using existing technology. The study was authored by Drew Shindell, of NASA Goddard and Columbia University, who had 23 coauthors from a total of 13 different institutions around the world (from countries including the US, UK, Italy, Austria, Thailand, and Kenya). The group concluded that the economic benefits of improved air quality and diminished global warming exceed the typical costs of these 14 approaches.

Read the rest of this article...

Read the comments on this post