Stories tagged greenhouse gas

Sep
20
2011

There’s been some buzz about the relationship between clouds and climate recently, prompting Andrew Revkin of the New York Times’ Dot Earth blog to get his panties in a twist about the “…over-interpretation of a couple of [scientific] papers…”

What gives? I wanted to know too, so I’ve done a bit – ok, a lot – of research and this is what I can tell you: The heart of the discussion is not whether there is a cloud-climate connection (that’s clear), but rather over what that relationship behaves like. There are at least three possible theories, but before we get to those, let’s review some important background concepts.

Gimme the Basics First

Cloud Formation

First, scientists think of air as units of volume called air masses. Each air mass is identified by its temperature and moisture content. Clouds are basically wet air masses that form when rising air masses expand and cool, causing the moisture in the air to condense. You can see the process in action yourself just by exhaling outside on a cool morning. The Center for Multiscale Modeling of Atmospheric Processes has a webpage to answer your other questions about clouds.

Earth’s Energy Budget
Earth's energy budget: Incoming solar energy is either absorbed (orange) or reflected (yellow).  Outgoing energy is radiated (red).  The arrows show the direction and magnitude of movement where thick arrows signify bigger movements.
Earth's energy budget: Incoming solar energy is either absorbed (orange) or reflected (yellow). Outgoing energy is radiated (red). The arrows show the direction and magnitude of movement where thick arrows signify bigger movements.Courtesy NASA

Energy from the Sun is essential for life on Earth. Let’s pretend the Earth has an “energy budget” where solar energy is like money, absorption is like a deposit, reflection is like a transfer, and radiation is like a withdrawal. It’s not a perfect analogy, but it’ll work for starters: Most of the incoming solar energy (money) is absorbed by (deposited into) the ocean and earth surface, but some is absorbed or reflected (transferred) by the atmosphere and clouds. Most of the outgoing energy is radiated (withdrawn) to space from the atmosphere and clouds. The figure to the right illustrates this process.

The Greenhouse Effect

Thanks to the greenhouse effect, our planet is warm enough to live on. The greenhouse effect occurs within the earth’s energy budget when some of the heat radiating (withdrawing… remember our budget analogy from above?) from the ocean and earth surface is reflected (transferred) back to Earth by greenhouse gases in the atmosphere. Greenhouse gases include carbon dioxide, methane, and water vapor. This National Geographic interactive website entertains the concept.

Climate Change

Climate change is occurring largely because humans are adding more greenhouse gases to the atmosphere. More greenhouse gases in the atmosphere means more heat reflected back to earth and warmer temperatures. Warmer temperatures might sound pretty good to your right now (especially if you live in Minnesota and could see your breath this morning as you walked to school or work), but it’s not. Why? Check out NASA’s really great website on the effects of climate change.

Alright, already. What’s the climate-cloud relationship?

From what I can tell, there are three possible theories about the climate-cloud relationship:

  • Clouds actively drive climate change. This is a linear process where clouds reflect too much heat back to Earth, which increases the average global temperature and causes climate change.
  • Clouds passively blunt climate change. This is a cyclical process where more climate change includes increasing average global temperature, which increases average global evaporation, which creates more clouds. More clouds absorb more heat, keeping the average global temperature from rising even faster and lessening climate change. This slows down (note: it does not stop) the rate of climate change.
  • Clouds passively amplify climate change. This is a cyclical process where more climate change includes increasing the average global temperature, which increases average global evaporation, which creates more clouds. More clouds reflect more heat back to Earth, which raises the average global temperatures and worsens climate change. This speeds up the rate of climate change.
  • So which is it? Probably NOT Theory #1. Maybe Theory #2… or maybe it’s Theory #3? Scientists aren’t quite sure yet, so neither am I, but the evidence is stacking against Theory #1 leaving two possible options. The next big question seems to be surrounding the size of the effects of Theory #2 and Theory #3.

    Using what you just read about cloud formation, the earth’s energy budget, greenhouse gases, and climate change (Woah. You just learned a lot!), what do you think? What’s the climate-cloud relationship?

    If you want, you can read more about what scientists are saying about the climate-cloud relationship here:

Oct
07
2010

What if I told you University of Minnesota geology and geophysics professor, Martin Saar, says geothermal energy can be made even greener through carbon sequestration?!

You’d probably say, “Huh?? Hold on, what is geothermal energy anyway, and how does it work?”

Geothermal is heat from deep inside the earth. Because heat is a form of energy, it can be captured and used to heat buildings or make electricity. There are three basic ways geothermal power plants work:

  1. Dry steam plants: Uses high-pressured hot steam to turn generator turbines. Think “steam to turbines.”
  2. Flash steam plants: Uses high-pressure hot water to create steam to turn generator turbines. Think “water to steam to turbines.”
  3. Binary cycle power plants: Uses high-pressure hot water to heat another liquid, which then turns to steam and turns the generator turbines. Think “water to other liquid to steam to turbines.”

(Click here for great diagrams of each of these geothermal energy production methods.)

“And what about carbon sequestration too? What’s that and how does it work?”
Carbon Sequestration: This nifty diagram illustrates both terrestrial and geologic carbon sequestration pathways.  Bonus!
Carbon Sequestration: This nifty diagram illustrates both terrestrial and geologic carbon sequestration pathways. Bonus!Courtesy Department of Energy

Carbon sequestration includes carbon (usually in the form of carbon dioxide, CO2) capture, separation, transportation, and storage or reuse. Plants, which “breathe” CO2, naturally sequester carbon, but people have found ways to do it artificially too. When fossil fuels are burned to power your car or heat your home, they emit CO2, a greenhouse gas partially responsible for global climate change. It is possible to capture those emissions, separate the bad CO2, and transport it somewhere for storage or beneficial reuse. CO2 can be stored in under the Earth’s surface or, according to Martin Saar’s research, used in geothermal energy production.

Alright. We’re back to Professor Saar’s research. Ready to know just how he plans to sequester carbon in geothermal energy production?

It’s a simple idea, really, now that you know about geothermal energy and carbon sequestration. Prof. Saar says geothermal energy can be made even greener by replacing water with CO2 as the medium carrying heat from deep within the earth to the surface for electricity generation. In this way, waste CO2 can be sequestered and put to beneficial use! As a bonus, CO2 is even more efficient than water at transferring heat.

But don’t take my word for it. Come hear Professor Martin Saar’s lecture, CO2 – Use It Or Lose It!, yourself during the Institute on the Environment’s Frontiers on the Environment lecture series, Wednesday, October 27, 2010 from noon-1pm.

Frontiers in the Environment is free and open to the public with no registration required! The lectures are held in the Institute on the Environment’s Seminar Room (Rm. 380) of the Vocational-Technical Education Building on the St. Paul campus (map).

Jun
25
2010

Agriculture is widely understood to be one of the largest contributors of greenhouse gases in our atmosphere, which is unfortunate for two reasons: 1) greenhouse gases are a driving force of climate change, and 2) last time I checked, people still need to eat.

Literally Green Skyscrapers: In a near-future world with 9 billion people, land will be even more valuable than it is today.  Researchers have been asking themselves how we are going to feed all those new people...  What if we built high rise greenhouses?
Literally Green Skyscrapers: In a near-future world with 9 billion people, land will be even more valuable than it is today. Researchers have been asking themselves how we are going to feed all those new people... What if we built high rise greenhouses?Courtesy Curbed SF

Specifically, farming is one of the largest contributors of carbon dioxide, methane, and nitrous oxide – all greenhouse gases – in our atmosphere. The four major sources of these emissions include fossil fuel consumption, fertilizer usage, animal farts and poop (no kidding!), as well as land use change (mainly, deforestation). As serious a problem as climate change is, one of the most important truths for environmentalists to remember is that people have needs that necessarily affect the health of the environment. For example, the world’s population is currently well over six billion people who need roughly 2,000 calories from food each day. That’s a lot of food that we depend upon farmers to raise and grow for us every day! And with predictions of nine billion people occupying the Earth in a mere forty years, our global population’s appetite is growing.

However, a June 2010 study published in Scientific American says that farming’s bad rap is undeserved, and actually modern high-yield crop farming has a net reduction of greenhouse gas emissions. Say what??

Here’s how it works: What sustainability-minded scientists from many disciplines strive to do is find ways to limit (better!) or eliminate (best!!) peoples’ negative impact on the environment.

In the 1960s, farmers and researchers began to develop new methods of farming to feed the rapidly expanding population. This has been called the “Green Revolution.” The results of their studies produced modern high-yield farming, which has allowed farmers to produce more food in less space. According to the Stanford researchers, though high-yield farming is possible largely because of fertilizer use – one of the four major sources of greenhouse gas emissions on farms – it prevents land use change in the form of deforestation – another one of the four major sources of greenhouse gas emissions on farms. The key point is that the greenhouse gas emissions caused by fertilizer use is less than the greenhouse gas emissions caused by deforestation, which yields a net reduction. That is, if we had continued with pre-Green Revolution farming techniques, in order to feed today’s population, we’d be using less fertilizer, deforesting more land, and emitting considerably more greenhouse gases than we currently are.

Today, at the Institute on the Environment, the Global Landscapes Initiative continues to focus on seeking ways to secure a healthy land use future for both people and the environment. This includes researching innovative agricultural practices.

Hydroponics: Hydoponics is a method of growing plants without soil.  Weird, but true!  Instead, plants are raised in a mineral water bath.  Could this be the future of farming?
Hydroponics: Hydoponics is a method of growing plants without soil. Weird, but true! Instead, plants are raised in a mineral water bath. Could this be the future of farming?Courtesy pchic

Another Scientific American article has it’s own ideas about how to provide food to our growing population: build vertical farms. These futuristic, skyscraping greenhouses are based upon existing hydroponic greenhouses and could reduce fossil-fuel use while simultaneously recycling city wastewater. Hydroponic greenhouses grow plants without soil! Instead, they use mineral nutrients dissolved in water, allowing plants to be grown just about anywhere… including on the 34th floor. According to the article,

“A one-square-block farm 30 stories high could yield as much food as 2,400 outdoor acres…”

That’s a lot of food. A lot. Really? Is it possible? The paper’s author claims it is and that architects, engineers, designers, and “mainstream organizations” are taking note of his vertical farm concept.

Jul
27
2009

Green energy? What about trying a little blue energy for a change? Blue seems just as wholesome and non-threatening, right?

In a similar vane to my last post on algae the geniuses of the world have come up with another truly brilliant "why didn't I think of that" kind of idea. It seems to make so much sense! It's so big ... and powerful ... and blue ...
We Have Come A Long Way: Now, just imagine that...but under water!
We Have Come A Long Way: Now, just imagine that...but under water!Courtesy Wikimedia Commons

Engineers at Blue Energy have developed, with support from the Army Corps of Engineers a turbine for the ocean. No no, not a wind turbine ON the ocean (my mom just made that mistake) but an underwater turbine that will harness the powerful ocean currents to create possibly the most sustainable energy source we know of!

Here is what we know: Water turbines will be placed in the Gulf Stream near Florida and they will work much like land wind turbines (using a rotater blade, which when made to spin by wind or water, creates energy!).

There is still a considerable amount of work to do before water turbines can be utilized. Frederick Driscoll, director of Florida Atlantic University's Center of Excellence in Ocean Energy Technology strives to be realistic about the future of water turbines. A resource assessment of the Gulf Stream is underway to help understand exactly how much energy can be safely extracted from the ocean, where exactly it should be extracted from and how to get the energy safely and efficiently to our homes without disrupting the ocean environment. So much to think about!
Always Something There: The strength of the Gulf Stream has been evident for hundreds of years.
Always Something There: The strength of the Gulf Stream has been evident for hundreds of years.Courtesy Library of Congress

Florida is the fourth largest state in the U.S. and the third largest consumer of energy. They are in dire need of a new energy source as many experts insist that Florida is on the brink of a very serious energy crisis. Much still needs to be done in the way of turbine technology in order to move ahead with incorperating them into the fleet of renewable energy sources. This past spring four acoustic Doppler current profilers were lauched off the coast of Florida to gather information about the currents, mainly to learn about the speed of the ocean currents. Ocean energy may become the crown jewel of the fleet.

Jan
08
2008

Large scale study shows 540% net energy gain when ethanol is produced from switchgrass

Panicum Vergatum: Switchgrass
Panicum Vergatum: SwitchgrassCourtesy U S Govt

Kenneth Vogel, a geneticist with the U.S. Department of Agriculture in Lincoln, Nebraska, and his colleagues, found that ethanol produced from switchgrass yields 540% of the energy used to grow, harvest, and process it into ethanol.

Their results, published online in Proceedings of the National Academy of Sciences, shows that switchgrass, farmed using conventional agricultural practices on less-than-prime cropland yields only slightly less ethanol per hectare on average than corn.

Farmers planted switchgrass on 10 farms, each of which was between 3 and 9 hectares. They then tracked the inputs they used--diesel for farm equipment and transporting the harvested grasses, for example--as well as the amount of grass they raised over a 5-year period. ScienceNOW Daily News

Switchgrass monoculture or mixed prairie grasses?

Anyone remember our Buzz post "Chalk one up for diversity"? David Tilman in that post is quoted saying, "diverse prairie grasslands are 240 percent more productive than grasslands with a single prairie species"
Now I read:

... Vogel says, is that yields on farms using fertilizer and other inputs, such as herbicides and diesel fuel for farm machinery, were as much as six times higher than yields on farms that used little or no fertilizer, herbicides, or other inputs to grow a mixture of native prairie grasses. ScienceNOW Daily News

Who is right? Can anyone explain why two reputable researchers are getting such different results?

New fossil evidence indicates that the ancestors of modern kangaroos walked on four legs, had fangs and climbed trees -- a sobering thought. Meanwhile, scientists studying marsupial flatulence have discovered that kangaroo gas contains no methane, and thus does not contribute to greenhouse gasses. A spokesman for kangaroos said he was glad no kangaroos were involved in changing the Earth's climate.

Dec
01
2007

All hail to the beer fridge!: Canadian beer drinkers are destroying the planet, but having too good a time to notice.
All hail to the beer fridge!: Canadian beer drinkers are destroying the planet, but having too good a time to notice.Courtesy Brian Warren

Canadians love their beer. However, possessing only the standard number of kidneys (2), they must drink it slowly, and store it until they are ready. To keep their cold ones, er, cold, they have developed the tradition of the “beer fridge” – an old, used refrigerator, kept in the garage or the basement, and used just for beer and snacks. (Newer, nicer fridges go in the kitchen.)

But a new study by the Canadian government claims that this piece of native culture is wrecking the environment. The old refrigerators use more energy than newer models. Researchers have suggested buy-back programs, which basically amounts to taxpayers buying me a new fridge. Finally, a government subsidy we can all get behind!

There’s no reliable data on the energy consumption of the beer-launching fridge, clearly the greatest achievement in the history of civilization.

A study in Norway shows that an adult moose emits about as much greenhouse gas in a year as a car. Cows are even worse.

A new study found a link between human use of fossil fuels and an increase in the severity of hurricanes. The burning of fossil fuels has increased the level of greenhouse gases in the atmosphere, which has led to the warming of oceans in regions where hurricanes develop. The warmer the ocean water, the more severe the hurricane.

Aug
27
2006

Pollution exchange: photo from  Wikimedia Commons
Pollution exchange: photo from Wikimedia Commons

Marketing pollution on the Chicago Climate Exchange

Most people will agree that something needs to be done about the pollution and greenhouse gasses resulting from our consumption of petrochemicals. One solution would be to encourage reducing emmissions by financially rewarding those that meet their quotas and penalize those that don't.

How it works

To illustrate, the American Electric Power's Mountaineer coal plant is America's single largest emitter of greenhouse gases - sending as much out from its stacks as Canada.

Last year the Mountaineer plant generated 10.5 million megawatt-hours of electricity, and a corresponding 8.6 million tons of CO2e. That would make its emissions, in CCX terms, a $39 million cost. If improvements yield just a 1 percent cut, the plant has almost $400,000 of emissions to sell. Looked at another way, the emissions are suddenly 20 percent of the cost of Mountaineer's fuel. CNN Money

The Chicago Climate Exchange (CCX) is the world’s first and North America’s only voluntary, legally binding greenhouse gas (GHG) reduction and trading system for emission sources and offset projects in North America and Brazil. Members make a voluntary but legally binding commitment to reduce GHG emissions.

By the end of Phase I (December, 2006) all Members will have reduced direct emissions 4% below a baseline period of 1998-2001.Phase II, which extends the CCX reduction program through 2010, will require all Members to reduce GHG emissions 6% below baseline. CCX website about page

AEP Mountaineer plant uses the CCX in three ways. If its emissions are below its allowance, it can sell the difference, meaning the company has an incentive to emit as little as possible. If it needs to emit more, it can buy the difference from another member. Or AEP can invest in an offset program - say, planting carbon-sucking trees - that would earn the company new credits. The goal of the CCX is to create a market for pollution that, in effect, becomes a mechanism for reducing it.

The cost to pollute has doubled in six months

The currency at the Chicago Climate Exchange is a Carbon Financial Instrument contract, otherwise known as a CFI contract. One CFI contract is equal to 100 metric tons of CO2. The price of a CFI unit was less than $1 in 2004, rose to $1.75 in Jan. 2006, and now (Aug) are over $4.

To see what Europe is doing

go to European Union Greenhouse Gas Emission Trading Scheme (EU ETS)