The even darker side of brown clouds

Atmospheric aerosols compete with carbon dioxide as an agent of warming.

In the charge against global warming, carbon dioxide has long held sway as public enemy number one. But now, less-recognized molecules are entering the fray as significant agents of global warming. Aerosols emitted from smokestacks, exhaust pipes and domestic cooking fires consist of substances such as sulphates and nitrates that scatter light and have a local cooling effect; they also contain black carbon — or soot — a byproduct of incomplete combustion, which absorbs light.

Scientists modelled the behaviour of the cooling particles years ago, but so few direct measurements have been made of the heat-absorbing effects of black carbon that, even now, models do not adequately represent their influence. The most recent assessment of the Intergovernmental Panel on Climate Change1 reported that the total contribution of aerosols to climate warming since the onset of the industrial era was about 20% of that caused by greenhouse gases. As much as half of the recent warming trend attributed to CO2 and other greenhouse gases is thought1 to have been cancelled out by cooling from aerosols. But new observations show that in some regions black carbon is as culpable as CO2 for the warming, and in some cases, has a greater effect.

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Prepare for another ten scorching years

Temperature records will be repeatedly shattered over the next few years, say researchers behind the first rigorous look at how global climate will change during the next decade.

The prediction comes from an innovative technique that combines the approaches used by weather forecasters, who typically look a few days ahead, and climate modellers, who produce projections that run up to the end of the century. The result is a model that can project as far as 2015, filling in a long-standing gap in climate predictions.

Although average global temperatures have been relatively flat in recent years, the model says they will start rising again next year. At least half of the years between 2009 and 2015 will exceed the current warmest year on record. By 2015, global temperatures will be 0.5 °C above the average value for the last 30 years.

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Eco-friendly and energy-efficient home building

Just finished five months ago, the Martin family home northeast of Edinburg is part of a new generation of energy-efficient and eco-friendly homes. The trend is gaining traction across the nation, not only because of the environmental impacts but because the technologies are becoming cheaper both up front and in the long term.

Even with 5,000 square feet of home, the Martin family pays the same for electricity, about $425 in July, as it did in its 3,000-square-foot McAllen home. And it all happened with a few careful choices during the home’s construction.

Special thick aerated concrete walls and high-tech insulation keeps heat out of the loft-style home while specially oriented windows let in light.

A geothermal piping system helps keep the air conditioning unit working more efficiently and a propane water tank heats faster and cuts down on waste.

“I get 70 percent more house for the same electricity bill,” said Martin, 32.

Green building

The payoff can be big for both homeowners and builders. Homeowners can save anywhere from 20 to 70 percent on electricity costs, while builders can net a $2,000 tax credit for building a green-certified home.

“I don’t consider myself an environmentalist. I drive an SUV,” Bill Martin said. “But I can save money by building this house the way I did, and I can help the environment while I’m at it.”

With “green building,” some homeowners go as far as using recycled materials, air-quality-conducive carpeting and paint. Others, like the Martins, simply use low-power lighting and heating.

Building a green home can add anywhere between 5 and 30 percent to a home’s up-front construction cost, said Mike Krismer, owner of Krimser Consulting.

“The whole green concept is very much environmentally friendly in terms of the materials that you use,” Krismer said. “But it’s also energy efficient.”

Homeowners can go green for as little as 5 percent more by adding energy efficient appliances, insulation and lighting; and as high as 30 percent with solar panels, high-efficiency building products and eco-friendly materials.
“I think people are ready here,” said Gayle King, a real estate agent and developer with Falling Water Realty. “Who wants to have a $500 electric bill.”

By 2010

The 9.24-acre Bentsen Lakes subdivision is set up with rules that encourage home purchasers to employ energy efficient design and use eco-friendly materials, such as insulated concrete forms and high-tech plastic foam insulations.

With increases in technology and lower costs for energy-efficient materials, some estimate that all American homes will be built “green” by 2010, said Jeffrey Dandeneau, chief operating officer of Valley-based Crossover Homes.

“There is a lot of product available here already and what we don’t have we can get very easily,” he said. “There is very little that we can’t already do.”

In the Valley, a key to building a green, high-performance home is making sure homes are sealed tight, Dandeneau said.

With high heat and humidity here, homebuilders can install better windows, insulation and wall materials to keep a home cooler and dryer during the day.

For his new home, Martin chose high-performance windows for most of his home — except for the massive windows in his kitchen, which provide much of the area’s evening light.

Martin also used high-tech blown foam insulation instead of standard fiberglass.

That helps seal the home better than normal porous fiberglass. It also doesn’t need to be replaced like other blown insulations.

The airtight home keeps the family cool during the day and comfortable at night.

“Sometimes it gets so cold at night that we have to turn off the air conditioner,” Laura Martin said.


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Congestion charge for gas guzzlers could be trippled to £25

The first official shots have been fired in the battle to force gas-guzzling cars off the road.

Drivers of 4x4s and high-powered sports cars will have to pay up to £25 a day to drive in the London congestion charging zone, it was confirmed.
This is expected to be followed by similar schemes across Britain - with cars charged according to how much carbon dioxide they emit from their exhaust.

London mayor Ken Livingstone announced a consultation starting tomorrow into higher charges for vehicles which "make the biggest contribution to global warming".

Under his proposals, drivers will pay £25 a day if their road tax falls into the top band G.

This will hit obviously thirsty cars such as Bentleys and Rolls-Royces.

But it will also affect school-run favourites such as the new Land Rover Discovery, BMW X5 and Jeep Cherokee.

Winners will be drivers of "lowemitting" cars in bands A and B, who will pay no congestion charge at all.
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