power paradox: clean might not be green forever
\"Look at the world\'s energy supply in the long run\" to create a better, richer and happier life for all our citizens.
This is the American dream.
In practice, it means living in spacious air.
A conditional house with one or three cars and perhaps a boat or holiday home, not to mention flying to an exotic destination.
The problem with this lifestyle is that it consumes a lot of electricity.
If everyone in the world starts to live like rich Americans, we need to generate more than 10 times of energy every year.
If in a century or three, we all want to be taken care of by the robot army and zoom into space during the holidays, we will need more.
Where will we gain so much power from?
It is clear that due to the dramatic warming effect of carbon dioxide, continued reliance on fossil fuels will have disastrous consequences.
But alternative energy also affects climate.
At the moment, the climate impact of \"clean energy\" is negligible compared to energy that emits greenhouse gases, but if we continue to use more energy in the coming centuries, they will become more important.
While such work is still in its early stages, some surprising conclusions have begun to emerge.
Nuclear energy, including nuclear fusion, is not a long time.
The answer to our energy question.
Even renewable energy like wind power must be used with caution because of large renewable energy sources
Scale extraction can produce both local and global effects.
These effects are not necessarily bad things, though.
We may be able to use them to change the climate and fight global warming.
Any planet is facing a fundamental problem.
As Eric Chasson of the Smithsonian Center for Astrophysics at Harvard, Cambridge, Massachusetts, pointed out, \"bind civilization \".
No matter what energy you use, it\'s almost the waste heat in the end.
For example, most of the electricity that powers your phone or computer will eventually heat the circuit.
The rest becomes radio waves or light, which becomes hot when they are absorbed by other surfaces.
This is also true when you use a mixer, electric drill or turn on the fan in the kitchen-unless you try to send a radio signal to an alien, almost all the energy you use will eventually heat the Earth.
We humans use 16 tawatts (TW)
At any one moment, this is nothing compared to the 120,000 TW solar energy absorbed by the Earth at the same time.
However, it is important to reach the balance between how much heat and the number of leaves (
See \"earth energy budget \").
If there is as much heat coming into the atmosphere as it does into the atmosphere, then the temperature of the Earth will remain the same.
If more heat comes or less heat disappears, the Earth will warm up.
When it does this, it starts to release more and more heat until the balance starts again
Established at a higher temperatureFIG-mg28491701.
JpgSee chart and colon;
The Earth\'s energy budget has been roughly balanced over the last few thousand years, with little climate change.
Now, the level of greenhouse gases is rising, reducing the heat by about 380 TW. Result:
The Earth is warming.
In contrast, the warming caused by the waste heat of about 16 TW produced by human beings is very small.
However, if human beings can thrive in the face of our great challenges and continue to use more and more energy, then waste heat will become a huge problem in the future.
Chaisson calculates that the Earth will warm up by 3 °c if demand for electricity grows to 5000 TW. This waste-
As the level of carbon dioxide rises, warm warming will be a supplement to warming.
In addition, since this calculation does not take into account any feedback that may amplify the effect, this degree of warming may occur below 5000 TW.
The use of such great power seems to be untrustworthy.
However, if our consumption continues to grow exponentially-despite rising prices, consumption has been growing at an annual rate of about 2300 this century-we may reach that point.
Chaisson described his work as a calculation of the \"back of the envelope\", hoping someone could prove him wrong.
No one so far.
On the contrary, a preliminary model of Mark Flanner of the National Atmospheric Research Center in Boulder, Colorado, shows that waste heat can lead to a warming of 0 in large industrialized areas. 4 °C and 0.
9 °C by 2100, consistent with Chaisson\'s estimate (
Geophysical Research Express, Volume 36, L02801).
Normal climate models do not include wasteheat effect.
Does this mean that human civilization has to limit itself to using no more than a few hundred megawatts of energy?
It depends on where the energy comes from.
If you turn the energy of the sun into electric energy and use it to boil the kettle, it will not make the Earth warmer than the same energy to heat the tiles on your roof.
But if you cook a kettle with fossil fuel or the energy of a nuclear power plant, you will add extra heat.
\"The only energy that won\'t heat the Earth extra is solar energy and its derivatives,\" Chaisson said . \" He refers to energy driven by the hot air, water and waves of the sun.
Therefore, while nuclear fusion can theoretically provide an effective unlimited source of energy, if our energy needs continue to grow, we will not be able to use it freely without significantly warming the Earth.
Carl Sagan, Chassen\'s mentor, seems right.
Chaisson said: \"Sagan used to preach to me a lot, and I am now preaching to my students that any intelligent civilization on any planet must eventually use the energy of its parent star, exclusive.
\"More specifically, they will be limited to solar energy that is usually absorbed by their planet-anything extra, including space --
Based on solar energy
Any intelligent civilization on any planet must ultimately rely entirely on the energy of its parent star. In theory, advanced alien civilization can generate a lot of waste heat and maintain a stable climate through Earth Engineering to resist waste. heat warming.
On Earth, however, the space to reduce greenhouse gas levels may be small, well below pre-industrial levels, as plants require carbon dioxide.
Adding a shadow to the Earth or increasing its reflectivity is also problematic.
Chaisson admitted that warming the heat is not important now.
Still, he thinks we are turning to solar power.
Based on energy as soon as possible.
\"Everyone agrees that steps must be taken to stop the rise of carbon dioxide in the short term, and then we need to worry about excessive heating of the atmosphere due to energy use in the long term,\" he said.
\"My point is, if we can do both at the same time, then why not take steps to do that now?
\"This is Mark Jacobson\'s music at Stanford University in California.
He has been pushing for an ambitious plan to switch to renewable energy on a large scale by 2030.
He envisioned wind and solar energy as 90 of them (
Energy Policy, Volume 1154).
On this scale, however, even renewable energy may begin to affect the climate. Wind power.
On 2010, Somnath Badiya Roy of the University of Illinois at Urbana-
According to champagne, wind farms affect the local climate. Long-
Term data from San Gorgonio wind farm in California confirm his early model prediction & colon;
In the evening, the surface temperature behind the wind turbine is higher than the front, but 4 °c lower during the day.
Roy thinks the flow of air generated by the turbine sucked the air off it.
During the day, this has a cooling effect when the hottest air is usually near the surface.
In the evening, when the air near the ground may be colder than above, it will have a warming effect.
By placing the wind farm in areas where there is already a large amount of turbulence, these effects can be minimized.
But we may not want to minimize them.
\"Some of these impacts are actually popular for agricultural reasons,\" said Cristina Archer, who studies wind power at Newark Delaware University . \".
Strategically, wind farms can keep crops cool during the summer and reduce the risk of frost in other seasons.
Farmers in California and Florida have started using wind turbines to withstand frost as they can pull warm air down.
Will Offshore wind farms affect sea surface temperature and steaming rates?
Will these local effects add up to major regional and even global effects? Perhaps.
Wind obviously plays an important role in the climate.
Slowing down or changing wind patterns will change the movement of heat and water around the Earth, thus changing temperature and rainfall.
It seems incredible that humans may have a significant impact on the wind, but we may already be doing so.
Although the wind speed of the ocean is increasing, the sea wind speed in Europe, Asia and North America has dropped by an average of 15 percentage points since 1979.
At least half of the slowdown is considered to be due to changes in land use, with more vegetation and possibly more buildings making the terrain rough (
Natural Earth Science, volume 756).
A 2004 study by David Keith of the University of Calgary, Alberta, Canada shows that the climate impact of wind power may begin to become apparent at the level of 2 TW.
According to Axel Kleidon and Lee Miller from the Max Planck Institute of Biochemistry in Yena, Germany, the impact of wind power depends on the proportion of the available power we extract.
They recently calculated how much wind energy is from top to bottom, starting with incoming solar radiation that drives the wind by generating temperature differences in the atmosphere.
They concluded that a maximum of 68 TW could be extracted.
Further simulations suggest that the available TW may be only 18 TW, far below other estimates.
What is more controversial is that the panel claims that extracting all available wind forces will have a huge change in temperature and precipitation.
While they do not suggest that the whole world will warm up, local changes are comparable in magnitude to those associated with CO2 doubling, according to their model.
Even if this conclusion is correct, we are still far from extracting the wind at this level.
At the end of 2011, the global wind power capacity was only 0. 2 TW.
Many others in the field are very skeptical about the team\'s conclusions.
\"I don\'t believe in their results,\" Archer said . \". \"The idea [the impact]
Twice as much carbon dioxide, it\'s just nonsense, \"agreed Gavin Schmidt, a climate scientist at NASA\'s Goddard Space Institute in New York.
There will be some big impact. scale wind-
But Miller\'s team exaggerated that, he said.
According to the bottom of Archer and Jacobson
Unlike Kleidon\'s estimates, the up estimate is based on actual measurements of wind speed, with 1700 TW wind at 100 m altitude on land and at sea.
Among them, 72 to 170 TW can be extracted at actual and cost
The model of the Jacobson team showed that 11 was extracted.
The 5 TW of this wind force will reduce the kinetic energy of the wind at 100 by less than 1.
The impact on temperature and precipitation is so small that it cannot be distinguished from natural changes, he said.
Science is far from conclusive.
However, even if the wind farm does have a significant impact on the climate, we can take advantage of this.
Careful placement of wind farms, for example, may increase rainfall in dry areas.
It is even possible to use wind power as a form of Earth Engineering (
See \"generate energy, cool the Earth \").
\"Near-some of the climate impacts
Is ground wind power desirable?
\"Of course,\" Miller said.
But he pointed out that this type of research is just beginning.
Of course, it is obvious that the increase in each wind farm means a reduction in carbon dioxide emitted into the atmosphere.
However, wind energy resources are relatively small compared to solar energy.
\"I don\'t think there\'s enough wind energy on Earth to do a lot of good things in the long run,\" Chaisson said . \".
\"Neither water nor waves.
The only way to endure is to learn how to use the energy of the sun.
\"Thousands of megawatts of solar energy can be generated using only existing technology.
Still, even solar energy can affect the climate, because solar panels can change the reflectivity or reflection rate of the surface.
A recent study modeled the construction of 1-
TW solar power plant in the Mojave Desert, California.
It concludes that so many dark solar panels are placed in the light
Colored sand will warm the air above.
4 °c, at 300-
However, if we develop more efficient solar panels in the future, similar solar plants will cool down locally.
No matter where the energy is finally used, the Heat ends.
In fact, if existing solar panels are placed on a dark surface, such as a black roof, they can also produce a partial cooling effect.
\"Solar panels basically absorb the sun and turn it into electricity,\" Jacobson said . \".
\"Then your house will be cold.
\"In addition, many other human activities, from the construction of cities to the cultivation of crops, have changed the rate of reflection, which has a greater impact because they affect a greater proportion of the surface of the Earth.
Temperature in the South
The decline in eastern Spain exceeded 0.
For example, since 1983, the temperature has been 6 °c because there are so many reflective greenhouses in the area.
So big though-
The massive use of solar energy may affect the climate, and as long as we do not capture hundreds of megawatts, otherwise these effects will be directly reflected back into space, then these effects will be relatively small.
The careful design and layout of solar power plants should minimize any negative consequences.
Some argue that any discussion of the climate impact of renewable energy and waste heat is a distraction from the more pressing task of reducing greenhouse gas emissions.
But if we don\'t start thinking about it now, one day we may find that we have created another climate problem in the process of solving one climate problem.