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
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
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 Most of the outgoing energy is radiated (withdrawn) to space from the atmosphere and clouds.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 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:
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:
Courtesy Mark RyanA new study published in Nature proposes that our Moon once had a companion satellite that it eventually accreted in a celestial collision. Planetary scientists, Erik Asphaug, of the University of California, Santa Cruz, and Martin Jutzi of the University of Bern in Switzerland devised computer simulations that show how it could have happened.
According to present lunar origin theory, four and half billion years ago, while the Earth’s system was forming, gravitational forces attracted a Mars-sized object that collided with the early Earth. The collision - more of a glancing blow than a direct hit - tossed terrestrial material into space that coalesced into our Moon. But during the period of coalescence – perhaps for tens of millions of years - a smaller companion moon (about 1/3 the size of the larger moon) would have been visible in Earth’s primitive sky. Geologically speaking, the mini moon’s existence would have been short-lived. The system was unstable, and sooner or later the moonlet’s orbit would decay and it would be pulled either into Earth’s mass or into that of the larger satellite.
Computer simulations set up by Asphaug and Jutzi reconstruct the latter taking place. The researchers propose that the dominant moon was still in a semi-molten state when its smaller companion collided with it at a sub-sonic speed. Being smaller, the doomed moon would have cooled faster and would have been more solidified, but the collision was hardly devastating. It’s low impact speed made it more like a clump of mud being lobbed against a wall. There wasn’t enough force in the collision to punch through, but just enough to make it stick.
More evidence: lunar composition differences
During NASA’s Apollo lunar program in the late 60s and early 70s, astronauts collected several samples of rock from the near side landing sites. The rocks brought back proved rich in potassium (K), rare earth elements (REE) and phosphorus (P) – hence the acronym. These elements, which are scarcer on the Moon’s dark side, crystallize very slowly in cooling magma, and remain molten until the entire mass of magma solidifies. So according to the researchers, when the collision occurred, it was enough to push much of the still molten magma - and the KREEP along with it - to the near side, and leave a pile of mountainous terrain on the far side.
I find this all pretty fascinating. The hypothesis answers several questions that have been puzzling lunar scientists for several years, and fits well into what we observe now. Of course we only see the Moon’s near side. Gravitational forces keep much of the far side hidden from us except via photography and lunar probes (Why that is can be learned here).
By the way, when you read about the gigatons of carbon emissions that human activities emit each year, it's helpful to have some perspective:
Let's talk gigatons--one billion tons. Every year, human activity emits about 35 gigatons of [carbon dioxide] (the most important greenhouse gas). Of that, 85% comes from fossil fuel burning. To a lot of people, that doesn't mean much -- who goes to the store and buys a gigaton of carrots? For a sense of perspective, a gigaton is about twice the mass of all people on earth, so 35 gigatons is about 70 times the weight of humanity. Every year, humans put that in the atmosphere, and 85% of that is power. Large actions, across whole nations and whole economies, are required to move the needle.
By comparison, our atmosphere is small--99.99997% of our its mass sits below the Karman line, which is often used to define the border between Earth’s atmosphere and outer space. At 62 miles above Earth's surface, it’s about as high as the distance between St. Paul, MN, and Menomonie, WI.
The oceans also absorb some of that carbon dioxide, but not without consequence.
Of course, the great part about being responsible is having capability--if our inventions bring about such transformations in the air and oceans, then couldn't we be inventive enough to reduce their negative impacts?
It's a world leader in clean energy investment and clean coal research and development. Last year, it manufactured a third of the world's solar panels and wind turbines, and it's luring companies from all over the world to build factories there. It has recently made huge investments in clean energy education. But it's not America.
Courtesy Jude Freeman
The country I'm describing is China. That's right--the world's newly-dubbed largest net emitter of greenhouse gasses. It isn't bound by reduction requirements under the Kyoto protocol, and its use of fossil fuels is powering a growing and booming economy. And yet, the Chinese are courting US companies with financial incentives to build clean tech factories and research centers in China. They're working to corner clean tech markets in California and South Africa. In fact, over the last three years, China has gone from controlling 2% of California's solar market to a whopping 46%--ousting its American competitors. And that's not all--the country has become a proving ground for clean coal with the guidance of US companies and researchers.
These companies hope to learn from their experiences testing clean coal tech in China, and bring that knowledge back to the US to transform our own polluting coal plants into next-generation powerhouses. So what's in it for the Chinese? They're quickly gaining lead on the cutting edge in green technology, making room for growth in the energy sector without increasing pollution or relying on foreign imports, and reaping economic benefits--and they foresee substantial economic benefits in the future, when they could be the major supplier of green technology and research to the world.
Given the US's slowing progress on clean technologies, what do you think this will mean for our future? Should we be trying to get on top of green tech research and development? Or is it best left to others? Or are those even the right questions--will we have the best success when we pool resources with other countries?
Courtesy Mark RyanResearchers in Japan are studying the wing structure of dragonflies to help improve how micro wind turbines perform during high winds. Micro turbines are small, affordable energy converters that can be used in both urban and rural settings where giant turbines would be too expensive, too large, and too impractical. Micro turbines can be set up relatively easily in configurations of a single unit or as a bank of several units, and the energy generated can be stored in batteries.
They work on the same principle as the large turbines, but can generate power in wind speeds as low as 4 or 5 miles per hour. One fallback, though, is their generators can get overloaded when hit with high storm winds, producing more energy than the system can handle. Large turbines solve this problem by tilting their propellers - either by computer or otherwise - and adjusting their rotation speed. But that kind of technology just isn’t affordable with micro turbines.
That’s where studying dragonfly wings comes in. Aerospace engineer Akira Obata of Nippon Bunri University in Oita, Japan wondered how dragonflies were able to remain stable in flight at low speeds. He placed a plastic model of a dragonfly wing into a large tank of water laced with aluminum powder and videotaped the flow patterns. He noticed that as the water flow slowed down vortices arose on the wing’s surface that allowed the water to pass over the wing at the same speed, thus keeping it stable. But when water flow sped up the wings aerodynamics performance decreased.
So, Obata developed an inexpensive paper micro turbine with similar “dragonfly wing” bumps on its surface and it did just as he hoped. When air speeds flowing over the turbine wing increased between 15 and 90 mph, rather than speeding up its rotation and overwhelming its battery, the micro turbine curved into a conical shape that stunted rotation and kept power generation low.
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:
(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?”
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).
Courtesy Mark RyanA new study appearing in the Journal of Palliative Medicine reports how several terminally ill patients all showed identical surges in their brain activity just before they died. At first the doctors at George Washington University Medical Faculty Associates who did the study thought the surge was being caused by interference from life-support machines or other electronic gear in the room.
“But then we started removing things, turning off cell phones and machines, and we saw it was still happening,” said lead author Lakhmir Chawla.
Speculation of what causes the neurological hyperactivity at the moment of death is that neurons in the brain, suddenly deprived of blood pressure and oxygen, shut down in rapid succession resulting in a final burst of neural activity - an electrical death rattle if you will. But the idea doesn’t seem to be a very new one. Kevin Nelson, a researcher studying near-death experiences at the University of Kentucky claims it’s well known that the brain experiences a sudden discharge of electrical energy when blood flow to it is cut off.
So, I’m not sure I see what the big surprise is here. If this is so well-known then why wouldn’t the doctors at George Washington University Medical Associates already know this?
But there’s another part of this that’s interesting. The surge may also be responsible for the "white light" reported by some patients who have had near-death episodes. The lore surrounding this phenomenon is about patients seeing an intense bright light when they're dying. But, according to Chawla, the majority of people involved in such incidents report having no such “white light” occurrence, but merely a vivid memory that may have been burned into their brain by the “final” electrical discharge.
And what about the so-called "out of body experience" patients sometimes report after slipping from the grasp of the Grim Reaper? Well, that, too, could come from the brain's electrical shutdown. A study that appeared in the journal Nature in 2006 reported patients sensing "shadow figures" laying nearby, or hovering above while certain areas of their brains were being stimulated with electrical currents. The charges interfered with the sensory information being received by the brain, and the hallucinations were just the brain's way of making senses of everythingl. The New York Times ran a story about it you can read here.
Bottom line, it looks like all those reported supernatural near-death experiences are just all in your head.
Courtesy Tallia Miller
Cooking food on an open fire may sound romantic but in reality breathing smoke and scrounging for fire wood make it not so pleasant. It is estimated that the smoke from cooking fires leads to nearly 2 million premature deaths each year.
A Global Alliance for Clean Cookstoves has formed to
"save lives, improve livelihoods, empower women, and combat climate change by creating a thriving global market for clean and efficient household cooking solutions."
A better burning stove should not be rocket science but several factors should help the Alliance meet their goal of 100 million households converting to clean cookstoves and fuels by 2020.
Starting with several existing cutting-edge technologies, NASA might be able to develop a way to catapult satellites and spacecraft into orbit.
An early proposal has emerged that calls for a wedge-shaped aircraft with scramjets to be launched horizontally on an electrified track or gas-powered sled. The aircraft would fly up to Mach 10, using the scramjets and wings to lift it to the upper reaches of the atmosphere where a small payload canister or capsule similar to a rocket's second stage would fire off the back of the aircraft and into orbit. The aircraft would come back and land on a runway by the launch site. NASA.gov
Making the impossible, possible - one prize at a time. This is the idea behind the X-prize movement. Flying into space, cleaning up oil spills, landing on the moon, or producing safe, practical cars that get 100 mpg are becoming reality as teams compete to win X-prizes.
To drive innovation, offer the right prize and human nature will do the rest.