Priligy online now, save money
Monitoring Pollution

Hailstorms and Tornadoes Thrive on Car Exhaust


If you wanted something else to blame on the internal combustion engine, you can now add tornadoes and hailstorms to the list.  Scientists have found that both weather events are more likely to occur during the week than the weekend due to the higher levels of pollution in the air from our workday commutes.

The study, published in the Journal of Geophysical Research - Atmospheres, looked at summer storm patterns in the eastern U.S. from 1995 to 2009 and found that hailstorms were occurring at a rate of about 20 percent above average midweek and about 20 percent below average on Saturday and Sunday. The team then looked at EPA records of summertime air pollution in the eastern U.S. and found that it peaks midweek.

The reason is that water particles cling to pollutants in the air, floating up higher in the atmosphere where it's colder and creating more hail.  Pollutants also create tornado-friendly conditions by making the air warmer.

The western U.S. doesn't experience this same phenomenon since the air is dryer and cloud masses are too high and cold for the air pollution to interfere with.

via National Geographic
 

China May Surpass U.S. Per Capita Carbon Emission Levels By 2017


A new report form the Netherlands Environmental Assessment Agency says that China's per capita carbon emissions are rising at such a pace that the country could reach, or even surpass, U.S. levels by 2017.

The report states that China's per capita carbon emission were at 2.2 tons in 1990, but have since risen to 6.8 tons.  That amount is about equal with Italy and more than France.  During that same time frame, U.S. per capita emissions have dropped from 19.7 tons to 16.9 tons.

China became the world leader in total greenhouse gas emissions back in 2007 and has doubled its emissions since 2003.

This breakneck speed of development and increasing carbon emissions has caused environmentalists to say that China should now be considered a developed nation during climate change talks, which would means it would be expected to take on more responsibility in controlling carbon emissions.

via Yale e360

 

Evaluating Energy Sources by Human Deaths

In all the furor during the Fukushima Reactor Complex crisis, there has been a lot of discussion about whether or not nuclear power is a good option and, more generally, what kinds of power should be used to meet increasing demand. An unusual piece that was making the rounds on this topic was an article about the number of deaths per terawatt-hour (TWh) for different kinds of power production. It's an interesting metric to use to weigh different methods of generating power.

Nuclear power, interestingly, is at the bottom of the list, with only 0.04 deaths per TWh, while coal tops the list with a world average of 161 deaths per TWh. The numbers for this were calculated looking at not only at direct impacts from power station accidents, but also indirect effects, such as coal miners' deaths and deaths due to air pollution, as well. The list gets difficult, though, when it starts to ascribe deaths in supporting industries to the total. Steel and concrete are needed to construct wind turbines, and the calculations extend to include industrial deaths in the mining and manufacture of those components, as well as transportation deaths. While it's not unreasonable to ascribe those fractions to the overall calculation, it does make it start to get a bit tenuous.

Rather than take any of these numbers as hard and fast conclusions (any two reasonable people could have long arguments over any number of assumptions in these statistics), the general trends and relative scale of each could instead be given consideration in weighing options. Although nuclear power may have a low associated death rate, the economic cost of the energy produced this way is quite high, and there is a great deal of public opposition and NIMBY reaction to new nuclear power plants.

A lot of the investment in nuclear power goes to safety and security, rather than to producing power. The money spent on backups and redundant safety systems for a nuclear plant isn't increasing power efficiency. A nuclear plant might cost as much as $8,000 (or more) per kW of electrical generating capacity (though this number is speculative, since no new nuclear plants have been built for many years), while a wind turbine might cost $1,200 to $2,600 per kW. A wind turbine won't necessarily generate power as steadily as a reactor, but it's a lot less expensive to build.

Operating costs are another big, but rarely discussed element in favor of many renewable power systems. Actively operated electrical generating facilities need many full-time employees operating the plant's various systems. However, solar and wind power facilities do not typically need the same active management. While the construction and installation costs may be higher, the operating costs might be far lower.

Construction costs, environmental costs, operating costs, financing and regulatory costs all enter into the power generation equation. All of these factors need to be taken into account to make more reasonable decisions about power generation.

link: Economics_of_new_nuclear_power_plants (Wikipedia)

images: CC Attribution-Share Alike 3.0 Unported by KEI at ja.wikipedia; Wikimedia Commons

 

Visualizing CO2 Emissions

May is a good month for commuting to work by alternate methods. Bike-to-Work Day is celebrated in many communities in May. In my town, we have a month long Commuter Challenge encouraging people to discover commuting alternatives. When I saw that the coworking space I am affiliated with had avoided about a half a ton of CO2 emissions, I started to wonder about what that volume looked like. The term 'ton' is used to mean 'a lot,' but how big is that when talking about a gas? A car weighs a ton or two (a current model Ford Focus has a curb weight of about a ton and a half), but it's made from much heavier materials. CO2 is a gas, though, so it is much harder to have an image of what it means to have a ton of CO2.

A little research and some calculation shows that a ton of CO2 will fill a volume of about 17,850 cubic feet at standard atmospheric pressure. To help visualize it, this is roughly the volume of a two story house, about 2,000 square feet in size (25 feet deep x 40 feet wide x 17.86 feet tall). Locate a house that is about that size, then imagine that volume filled with pure carbon dioxide; that’s what one ton of CO2 is.

And that’s just the carbon dioxide. If we are talking about automobile emissions, then there are all kinds of nitrogen oxides, uncombusted hydrocarbons, soot, and other pollutants that are being put into the atmosphere, as well.

To get a sense of larger volumes, the Hindenburg was about 6 million cubic feet in volume. That would be about 336 tons if it was filled with CO2. The New Orleans Superdome has a building volume of about 123.6 million cubic feet, which would hold almost 7000 tons of CO2. It would take more than 140 Superdome buildings to contain a million tons of CO2.

Another way to look at it is to think about how long it takes for you to put a ton of CO2 into the atmosphere. The EPA uses the figure of 19.4 pounds of CO2 per gallon of gas. So, roughly speaking, every 100 gallons of gas you use puts a ton of CO2 into the atmosphere. A car that is driven 12000 miles and averages 24 MPG in a year puts 5 tons of CO2 into the atmosphere.

An earlier version of this article appeared on the GetDowntown blog.

 

New Map Shows Size of Forests in U.S.


A new map created by the Woods Hole Research Center shows the height, coverage and carbon storage levels of forests in the U.S.  The map was put together by using NASA satellite images from 2000-2001 as well as ground-level surveys by the USGS and USDA Forest Service.

The dataset for the map includes the forest measurements amount of carbon stored in vegetation as of 2000.  The scientists involved in the project will use the map as a baseline to monitor changes in forest cover and the carbon cycle.  This will allow them to make predictions about climate change and wildfire risks, help species conservation and even regulate the timber industry.

This is the first map to provide canopy height and carbon storage information at this level of detail.  You can check out the full high-resolution map and dataset here.

via U.S. News Science

 
Start   Prev   1 2 3 4 5 6 7 8 9 10   Next   End

Page 3 of 14

Are you an EcoGeek?

We've got to keep 7 billion people happy without destroying our planet. It's the biggest challenge we've ever faced....but we're taking it on. Are you with us?