Tips Guides

The Earth and Venus are near each other in the Solar System, and are similar in size, density, and composition. Based on our understanding of the origin of the Solar System, we would expect that their initial atmospheres would have been rather similar. Yet the present atmospheres of the two planets could hardly be much more different than they are. How did this come to be? The reason is thought to lie in what is termed the “Runaway Greenhouse Effect”.

Sunlight falling on the surface of a planet is primarily in the visible part of the spectrum. However, the reflection of light from the surface tends to produce light of longer wavelength called infrared (IR) radiation (also known as radiant heat; IR radiation is the heat that we sense being radiated from a hot surface like a hot piece of metal).

Now, because of their molecular structures, certain gases like carbon dioxide and water vapor (and many others) have the property that they are essentially transparent to visible light but absorb IR radiation very strongly. Such compounds are sometimes termed greenhouse gases because, if they are present in a planetary atmosphere, they absorb the scattered IR radiation and tend to raise the temperature of the atmosphere by trapping solar energy. (The analogy with a real greenhouse is imperfect because the mechanism by which a greenhouse stays warm is different, but it is sufficiently good that the name “(Planetary) Greenhouse Effect” is now the common one for this phenomenon.)

The greenhouse effect occurs for all planetary atmospheres containing greenhouse gases, and is responsible for their being warmer than would be the case otherwise. The greenhouse effect by itself could not account for the conditions that we find on Venus. However, under certain conditions we believe the greenhouse effect can “run away”. For example, consider the case of a planet like the Earth. The Earth has enormous amounts of two greenhouse gases: water vapor and carbon dioxide. However, for the Earth most of the water and carbon dioxide are not in the atmosphere. The water is mostly in the oceans, and the carbon dioxide is mostly bound chemically in rocks made from compounds that chemists call carbonates (for example, limestone).

Now suppose we increased the effectiveness of greenhouse heating of the Earth’s atmosphere, for example by increasing the amount of solar radiation falling on it, or by increasing the concentration of greenhouse gases in the atmosphere (for example, by burning fossil fuels, which produce water vapor and carbon dioxide as byproducts of burning). We would then expect the temperature to rise in the atmosphere (assuming no other effects intervened—a big “if” in the realistic case since the atmosphere is complicated). This would be a greenhouse effect.

It would become a runaway greenhouse effect if the rising temperature approached the boiling point of water, because then the oceans would begin to convert to water vapor, the water vapor would increase the effectiveness of heat trapping and accelerate the greenhouse effect, this would cause the temperature to rise further, thus causing the oceans to evaporate faster, etc., etc. (This type of runaway is also called a “positive feedback loop”.) When the oceans were gone the atmosphere would finally stabilize at a much higher temperature and at much higher density, because all the water would now be in the atmosphere.

We can envision even a further runaway stage in this scenario. Suppose the preceding runaway raised the temperature so high that chemical reactions begin to occur that drive the carbon dioxide from the rocks into the atmosphere (the process is called sublimation; a few hundred degrees Celsius would be sufficient). Then another runaway would occur as the carbon dioxide feeding into the atmosphere would accelerate the heating, which would in turn accelerate the transfer of carbon dioxide from the rocks to the atmosphere.

The atmosphere would finally stablilize at a still higher temperature and pressure after all the carbon dioxide had been driven from the rocks. In fact, we believe that if this sequence were to take place on the Earth, the resulting temperature and pressure of the atmosphere left behind would not be very different from that for present-day Venus: the atmospheric termperature would be hundreds of degrees Celsius and the pressure would be maybe 100 times greater than it is today.

Thus, we believe that in the case of Venus the initial solar heating kept oceans from forming, or kept them from staying around if they did form, and the subsequent lack of rainfall and failure of plant life to evolve kept the carbon dioxide in the atmosphere rather than binding it in the rocks as is the case for the Earth; thus, Venus has an environmental disaster for an atmosphere.

The sobering warning for us is obvious: we have to be extremely concerned about processes such as burning of fossil fuels in large volumes that might (we don’t know for sure because the scientific questions are complex) have the potential to trigger a runaway greenhouse effect and produce on the Earth atmospheric conditions such as those found on Venus.

James Nash is a climate scientist with Greatest Planet (www.greatestplanet.org). Greatest Planet is a non-profit environmental organization specialising in carbon offset investments.

James Nash is solely responsible for the contents of this article.

Placing recycling bins in the office is the responsible thing to do… but let’s face it - these bulky bins aren’t the most attractive pieces of decor! Because they still need to be accessible and removed for emptying and cleaning, they pose particular issues from a decorating point of view. However, recycling containers are now available in a variety of shapes, colors, styles and are fully customizable to make your green business truly fashionable.

Options for Recycling Bins

Bins for recycling are no longer the plastic blue tubs they were when they first came out. There are now recycling bins on the market in an unlimited number of custom colors, unique textures, and patterns. The company logo, motto, contact information, and anything you can dream can be printed on the outside of containers to emphasize the company brand within the office. For those that don’t prefer the look of plastic, there are receptacles available in other, more “fashionable” materials stainless steel and fiberglass.

Even the styles have changed considerably since the early days of recycling containers. Sleek, modern designs have emerged, leaving behind streamlined systems that have multiple compartments for all your environmental needs. Round and square styled bins for recycling are available as well as stackable units to fit into virtually any space.

Location of Recycling Bins

Bins for recycling need to be in a convenient location while still fitting into your business decor. However, if you’re like most, you’ll want to tuck them away whenever possible, while still ensuring that they are accessible. Many places set smaller bins under the desk, but this isn’t the only placement option. Consider special styles designed to fit right where you need them. In-cupboard styles are ideal for coffee areas and narrow containers fit between file cabinets or desks. Multi-section containers can replace garbage cans altogether.

Placing recycling containers where the majority of waste is generated is easier on employees and ensures that more materials will be recycled. Photocopiers, file cabinets, and desks are common sources of paper waste. Cardboard often comes from shipping and receiving departments, and compost from the lunchroom. Simply consider what type of waste you’re dealing with and where the majority of it comes from.

Recycle Bins in Disguise

Sometimes, decorating bins for recycling is the best way to incorporate environmentally friendly practices into your business. Decorative tins, wicker baskets, and wooden crates are ideal for hiding your recycling containers. If you are working in a smaller space, add bench seats that the receptacles can sit into. You can make them more comfortable by adding coordinating cushions. For added convenience, make a pair of small slots to allow you to feed the paper through. Add fabric to wire framing for a softer, more decorative look.

Switching over to green business practices doesn’t have to affect the overall look and feel of your business. The style and look of recycling bins are completely customizable and can be made to fit virtually anywhere. Keep in mind, however that having customers aware of recycling containers isn’t necessarily a bad thing either. Many consumers today will select environmentally conscious businesses over companies who do not see the value of bins for recycling and other green practices. Select your location, choose your recycling bins, and enjoy all of the benefits of this valuable practice.

Author is a freelance copywriter. For more information on Recycling Bins
please, visit http://www.wastewiseproducts.com.

The earth is undergoing a terrible bout of global warming with the carbon that is emitted by the burning of fossil fuels to generate electricity and when used in vehicles for transportation purposes. Moreover the sources of this fossil fuel are fast diminishing with the increased need of energy with the modernization of countries.

This is the reason scientist and researchers all over the world are thinking and looking for alternative sources of energy which are also renewable and available naturally. And such a source of energy is the energy found in areas having large tidal ranges.

France has been harnessing energy found in tides of bays and estuaries since 1966. Canada and Russia have followed suit and have also managed to generate electricity from tidal waves. Basically, it is possible to harness and generate electricity from places where there is a large tidal range.

This energy of tidal waves is harnessed by trapping the water so that it is used to turn turbines. The energy so produced is released through tidal barrages found in either direction. However, generally implementation of tidal power technology worldwide proves to have little potential because of its environmental constraints.

Another reason that is considered to be attributed to the low potential of tidal wave energy is that it would produce electricity more efficiently if it generates electricity in bursts at gaps of perhaps six hours. However this is not feasible as it is the limits of tidal energy applications that hinder the use of tidal energy.

This is why a new form of technology has been devised, to harness this tidal energy. This new technology is found in the form of tidal stream generators which tend to draw energy found in underwater currents. It could be said that the principle used here in these tidal steam generators is similar to the technology found in wind generators, which are powered by wind.

In such cases of generation of electricity by tidal power, the higher is the density of the water; the better is the potential for a single generator generating significant levels of power. However today, tidal stream technology is in its budding stages where there is much more research to be done before it can be said that tidal stream technology is an important part and contributor to the generation of energy.

There are a few prototypes that have been devised to harness tidal stream power, and show great promise in this direction. One such prototype is the 300 kW Seaflow marine current propeller type turbine that was tested off the coast of Devon of UK, in the year 2003. Another prototype is a 150 kW oscillating hydroplane device, called the Stingray that was tested off the Scottish Coast.

The Hydro Venturi is another British prototype that is slotted to be tested in San Francisco Bay pretty soon. In addition to all this, the Canadian company, Blue Energy has ideas of installing large arrays of tidal current devices on their tidal fence in various locations around the world. These devices are planned to be based following a vertical axis turbine design with which more tidal energy is produced efficiently in the world.

James Nash is a climate scientist with Greatest Planet (www.greatestplanet.org). Greatest Planet is a non-profit environmental organization specialising in carbon offset investments.

James Nash is solely responsible for the contents of this article.

When going for a morning walk, there are many beautiful butterflies in the air and sunning on plants or flowers. Of course, the expectation is that these beautiful creatures will be in your yard, too. Arriving home to a butterfly-free yard can be really disappointing. What can you do to make your backyard a haven for butterflies?

First - Without a doubt, you have to stop using chemical pesticides, fertilizers and herbicides. These are deadly considering that butterflies begin their life as a caterpillar attached to a plant within a cocoon.

Second - once you’ve eliminated this threat, the next important step is to provide ‘host plants’ to support the metamorphosis process. There are specific plants that will attract specific butterflies.

The Black Swallowtail prefers carrots, dill, fennel and parsley where the Great Spangled Fritillary loves violets. The beautiful Monarchs are attracted to milkweed, but the Pearly Crescentspot goes for asters. To attract Pipevine Swallowtails try planting pipevine, of course. Several varieties are Calico Pipe, Dutchman’s Pipe, Rooster Flower and Virginia Snakeroot.

Red-Spotted Purple butterflies are attracted to wild cherry and willow trees. The Spicebush Swallowtail prefers sassafras and spicebush. For the beautiful Viceroy plant cherry, plum, poplar and willow trees.

Third - Once the metamorphosis of a caterpillar into an adult butterfly is completed, they will begin to seek nectar sources. Incorporate into your garden nectar plants that bloom from the start of the season to late summer and fall. Select native nectar plants such as wild columbine; lance leaf coreoposis; rose verbena; swamp and whorled milkweed; New England aster; button bush; butterfly weed; orange, purple Missouri and sweet coneflowers; blue lobelia; cardinal flower; prairie blazing star and Joe Pye weed.

Butterflies will also be attracted to slices of banana, which attract fruit flies. They consume the fruit flies for protein and minerals. Put out a slice of watermelon or overly ripe fruit, and you’ll be amazed at all the butterflies that stop by for a light lunch. There are also a variety of butterfly feeders that hold prepared nectar or fruit.

Fourth - Remember to provide butterflies a place to warm in the sun. One idea is to build a waterless pond. Arrange heat-absorbing rocks on their side in a sunny area. Add sand and salts and keep the rocks moist. Be sure to line the area with plastic to keep salts from leaking into the soil.

Many people enjoy having an attractive butterfly house in their garden. While there is no proof that butterflies use these, it does add a colorful accent.
These colorful houses also make wonderful decorative additions to a porch or sunroom.

The six most common butterfly families you can attract are:

Swallowtails (Papilionidae) - The most noticeable thing about swallowtails is a club-like projection extending from the hind wing. The most common swallowtails include: Easter Tiger, Giant, Spicebush, Eastern Black and Zebra.

Milkweed Butterfly (Daneidae) - These medium to large size butterflies are all power flyers, and all eat various types of milkweed. The most common is the Monarch. The Monarch imitators include: Viceroy, Fritillaries, Mourning Cloaks and Admirals.

Gossamer Wings (Lycaenidae) - Over 100 species of these small butterflies reside in North America. They include the Blues, Coppers and Hairstreaks. The gossamers hold their wings closed over their backs when at rest.

Sulphurs (Pieridae) - The Sulphurs are hard to miss because of their brilliant yellows.

Whites (Pieridae) - Whites are often the first butterflies to be noticed in the spring. Many people assume they are moths due to their lack of color. Male “Whites” and “Sulphurs” are prone to “puddling”, which is gathering in groups near moisture and/or salts.

True Skippers (Hesperiidae) - They are small butterflies that are not particularly attractive, and contain antennae with a telltale fishhook-like curve to the end section. Their flight resembles a stone skipping across the surface of a lake.

Use the tips provided to attract these most beautiful of nature’s creatures so they will become permanent visitors to your garden.

There is nothing more relaxing than sitting in a chair or swing on your patio, deck or porch and watching butterflies make a graceful trip around your yard.

Even in today’s hectic times, all seems right with the world as a butterfly pauses to sip some nectar or relax on a warm rock.

Janet Winter loves her wild birds and delights in providing helpful resources and unique products for feathered friends at WildBirdGoodies.com. She is a web designer, travel agent and writer on many topics including wild birds, babies and pampered dogs.

You think you understand renewable energy credits. You’re sure you understand Carbon Offsets. You are fuzzy on the details about how they differ and when the purchase of one or the other might be appropriate. Never fear! This article explains the key differences, and similarities, between the two.

The first difference is the way that offsets and Renewable Energy Credits (RECs) are measured. Carbon offsets are measured in metric tons of C02 or C02 Equivalent. Renewable Energy Credits are measured in kilowatt hours, which are a standard electricity measurement metric. A kilowatt hour is the amount of work that can be performed by one kilowatt of energy in one hour.

Picture a lonely, dim lightbulb hanging from the ceiling that turns on for one hour each day by which you feverishly darn socks in a carbon constrained world; that’s a watt, and for the privilege of its use, you’ll be charged for 1/1000 kwh of electricity each day. These days, you probably use a several kwh per day.

The second difference between carbon offsets and renewable energy credits is that renewable energy credits only come from renewable energy projects (solar, wind geothermal, biofuels, etc.) while carbon offsets can come from all different kinds of projects, including renewable energy generation, that reduce the level of greenhouse gases that are entering the atmosphere.

To put it another way, RECs are primarily concerned with promoting the generation of clean energy, while carbon offsets are primarily concerned with preventing the emissions that enter the atmosphere.

They are both systems that have developed to deal with global warming systematically, but they have different approaches. RECs are forward looking, focused on building a clean energy economy and providing an extra incentive for the creation of renewable energy, while carbon offsets are oriented in the present, dealing with preventing greenhouse gases from entering the atmosphere right now.

Because of these different measurement systems and the different foci of the two programs, RECs and carbon offsets have different precision rates when it comes to carbon. Carbon offsets are all about exactitude, and many of the discussions about the efficacy of offsets center around the degree of certainty a buyer has that the exact amount of carbon s/he has paid for is actually being prevented or captured. RECs, on the other hand, are measured in kilowatt hours, and the carbon content of that ’saved’ kwh differs depending on the location of the project and the quality of the local electricity.

The dirtier the local electricity, the more carbon an REC ’saves.’ Different utilities around the country use different mixes of energy sources, from coal to natural gas to renewables, to create electricity. These sources vary widely in their carbon content. To make matters even more confusing, a utility might even change the mix it uses depending on the time of day- when peak load sets in they might have to rely on dirtier power sources than they would otherwise.

So, it’s impossible to say exactly how much carbon a clean kwh of renewable energy ‘offsets.’ The closest we can get is to use the ‘emissions factor’ for energy from the local utility, which is the average emissions for the mix of sources that the utility uses to create power, and multiply it by the number of kilowatt hours to produce an estimate of the carbon saved per kilowatt. But it will always be an estimate.

This is not to say that RECs are no good. They are an extremely effective way to promote clean energy because they give the providers and extra incentive to keep creating clean energy and we need all the incentives we can get to move toward a clean energy economy. RECs just aren’t the most accurate way to offset carbon. I highly recommend using RECs to offset electricity use, because your electric bills will have a record of the exact number of kwh you used, and you can buy RECs to account for all the dirty emissions your plugged-in Macbook caused. Then, you can buy carbon offsets to cover all your driving and flying.

‘But what about renewable carbon offsets?’, you say. ‘Those seem like the best of both worlds!’ I’m getting there. Those are good to, and if you really value the promotion of clean energy despite some of the accuracy issues, you can buy renewable energy offsets. Many times offsets will actually come from the exact same projects as the RECs, but the nice thing about buying the offset version instead of buying RECs and doing the calculations yourself is that someone else, hopefully a third party verifier, is determining how much carbon each kwh of clean energy replaced. So you don’t have to! Rest easy, and lay off the carbon guilt.

James Nash is a climate scientist with Greatest Planet (www.greatestplanet.org). Greatest Planet is a non-profit environmental organization specialising in carbon offset investments.

James Nash is solely responsible for the contents of this article.

Known previously as Town Lake, Lady Bird Lake is actually the portion of the Colorado River that runs through the center of Austin, dammed on either end to create a peaceful waterway with plenty of boating opportunities. The Town Lake Corridor, surrounding the water, is full of hike and bike trails, parklands, sports fields, music and festival locations - with views of the Austin skyline competing with the serenity of river’s vistas.

The Town Lake Corridor includes both north and south banks of Lady Bird Lake, bounded by Cesar Chavez to the north, and the appropriately named Riverside to the south, with Tom Miller Dam marking the western boundary, and the Colorado River Park to the east. Within this huge, rambling area, you will find over ten miles of some of the most popular and scenic hike and bike trails located in Austin. Wildly popular, the trails are shared by runners and walkers, bikers and strollers, dogs and people alike. The 8 miles that flank the river are wide, level, shady, and have trail markers, water fountains and benches scattered along the way.

Boating on Lady Bird Lake is perennially popular both for sporting teams and for recreational boaters. No motors are permitted, allowing visitors to enjoy a relaxing day rowing, canoeing, kayaking or peddle boating. The Rowing Dock is a Town Lake Austin Parks and Recreation concession where visitors can rent boats by the hour. They also offer camps, private lessons, classes and memberships.

No visit to Town Lake would be complete without a pilgrimage to the Steve Ray Vaughan Memorial Statue, located on the south side of the River. Mounted by the City of Austin in 1994, the homage to the late great Texas blues guitarist is directly adjacent to Auditorium Shores, not coincidentally one of Austin’s most popular periodic outdoor music venues. Vaughan played Auditorium shores during his abbreviated career, and it remains a top stage, featuring local and national acts.

Town Lake Park boasts 17 ball fields for baseball, football, soccer and rugby, and volleyball, and on its western perimeter adjoins Zilker Park, making this easily the biggest recreational area in the city. Its proximity to downtown Austin means that many dining options can be found within blocks on either side of the water, including the “restaurant row” located on Barton Springs Road. Austin’s perennial favorites such as the Shady Grove, Austin Java, Chuy’s and the Green Mesquite join relative newcomers including P.Terry’s Burger Stand, and Flip Happy Crepes - located in a shining silver Airstream trailer. The popular South Congress and South First dining and shopping areas are in walking distance as well.

On July 26, 2007, the Austin City Council passed a resolution authorizing the renaming of Town Lake to Lady Bird Lake in honor of Lady Bird Johnson, the former First Lady of the United States and a long-time resident of the Austin area. Although Johnson had declined the honor of having the lake renamed for her during her life, her legacy as a proponent of nature and beauty endures after her passing.

Ki lives and works in Austin. He runs a map based Austin MLS search on his site along with detailed information about Austin real estate. His website also has updated info on mortgage interest rates.