The great thing is that we can simply measure the warming of the planet and determine the effects. We're running the experiment right now. Anyway, as far as we know, even if the climate sensitivity is as low as 1.2 degrees Celsius, we still need to be doing more to reduce carbon dioxide emissions than we have been doing. According to the IPCC, the climate sensitivity is between 1.1 and 6.4 degrees Celsius. Whatever it is, we will need to reduce carbon dioxide emissions to prevent warming in excess of 2 degrees Celsius. After we reduce emissions some, we'll get more data in so we can fine tune our policies.
I have the equivalent of an AS degree in physics, and you have no idea what you're talking about. The Earth most definitely is in thermal equilibrium. Take, for example, these notes from the University of Oregon that states that "earth wants to stay in thermal equilibrium". If we produced thousands of petawatts of power from fusion, we could warm the Earth. The Earth would respond by emitting more radiation and cooling down. What is happening instead is that increased greenhouse gasses are causing less radiation to be radiated into space, causing warming. It's very simple physics, and all these effects were predicted by Arrhenius over 100 years ago.
The statement you are referring to is that over a recent ten-year period, there is just over a 5% chance that the warming over that ten-year period could possibly have been due to chance alone. In other words, there is less than a 95% chance that the warming was due to increased carbon dioxide in the atmosphere. If you take longer time periods, we are more than 95% sure that the warming is not due to chance.
It's just the same as if you keep flipping a coin, and you get 7 heads in a row. There is a 1 in 64 probability for getting either 7 heads in a row or 7 tails in a row, so you can't determine whether a coin is fair or not to a 95% statistical significance by flipping it only 7 times. If you flip it 100 times and it comes up heads 70 times, however, it's almost certain the coin isn't fair. That's what TFA is saying. We're sure the warming is not a chance occurrence. It is undeniable that the warming trend is not just a random fluctuation. The Earth really is warming.
I understand chaos. A butterfly flapping its wings could cause a dramatic change in weather. It would not change the climate. Changing the climate would require massive amounts of energy to cause the climate to shift to a new state. This is exactly the effect doubling the concentration of carbon dioxide has. It causes the Earth to radiate less heat into space, so the Earth warms to a new equilibrium temperature. Jeez, some people just don't grok physics, do they?
NASA scientists have probably just made up this asteroid impact so they can get rich by getting grants to study the chance of impact and what to do about it. Politicians will love it because it gives them an excuse to raise taxes to deal with the possible impact. Of course, asteroids have been impacting the Earth for millions of years, so it can't possibly be anything to worry about. They should prove that we can avoid the impact before they spend any money on attempting to avoid it. We don't even know if the impact will happen, because multiple orbital bodies are a chaotic system, so we can't possibly predict where they'll be in 172 years.
There's not enough land to plant that many trees. Each human being emits about six tons of carbon dioxide each year on average. Where is each person going to put six tons of trees per year?
What makes you say climate is chaotic? Weather is certainly chaotic, because a slight change in initial conditions could cause a large change a few weeks from now. A slight change in wind direction today could mean that Chicago sees sunny weather next week instead of a rain storm.
But climate doesn't work that way. The climate remains stable unless conditions change fairly dramatically. For example, predictable changes in the Earth's orbit cause ice ages and interglacial periods. Why would you say the climate is chaotic? Does it have a sensitivity to initial conditions?
I don't understand what your point is. To what trend are you referring? Are you saying that it was warmer in the past, so we don't have to worry about warming?
No, I have no doubt at all. The problem is that whether the warming took place over 100 years or 1000 years, they all appear as vertical lines. A graph of a million years is useless to look at rates of warming over decades.
Why wouldn't we simply fail to reduce carbon dioxide emissions if we couldn't generate enough power from non-emitting sources? I don't see anyone making it illegal to meet energy demand, so it doesn't seem like anyone is proposing energy rationing.
Sorry, I don't pay much attention to sensationalist media. They tend to report on either one extreme or the other, or cover both extremes and not the middle for what they call "balance". I read what scientists say will be the effects of global warming. I try to watch their lectures to the public, which are explained well enough for non-climatologists to understand and not sensationalized and distorted by the media.
You forgot... "But it's been dripping for years and we've been okay. I'll show you this nice graph showing that the water level has remained low for years! It doesn't matter that I just put $50,000 in cash down there and the pipe just burst." Oh, and, "You have to prove to me that turning off the water at the water main will help even before I undertake such a drastic action that will shut off all the water to my house!"
I don't think anyone is actually worried about a runaway greenhouse effect on Earth. We're working on reducing carbon dioxide emissions to reduce warming, not to prevent a runaway effect. I think you've been reading too many sensationalist media articles.
So there can't be any convincing evidence without a controlled experiment? I wonder how geologists and astronomers work, then...
Anyway, what's so "drastic" about increasing energy efficiency and increasing production of alternative energy sources? I think you're being a bit... alarmist.
Who is proposing "global power rationing"? Generating biofuels will not take much of a chunk out of fossil fuel use, but it's needed to power large aircraft and ships if we're to reduce carbon dioxide emissions to below 20% of current levels.
It's not supposed to induce a sense of panic. It's supposed to explain why it would be a good idea to reduce carbon dioxide emissions. It will save money in the long run. It's a very reasonable, logical decision, not an emotional, panic-stricken knee jerk reaction.
The current rate of warming is 0.2 degrees Celcius. On any graph of temperatures going back millions of years, the temperature increase over the past several decades appears as a vertical line. To predict the rate of warming over the next century, it would be more informative to use a graph of the past century or so.
Millions of years ago, a warmer climate might have been a good thing overall. But warmer temperatures and rising sea level in the 21st century will cost trillions of dollars.
But there's no proposal to "change our entire civilization". All we need to do is cut net carbon dioxide emissions. We can do this by increasing energy efficiency, building nuclear power plants and solar power plants, and manufacturing biofuels. I can understand why so many people want to deny global warming when their lifestyle is at stake, but it isn't.
But the rate of warming has recently increased dramatically. The slow warming that ended the last ice age was due to changes in the Earth's orbit. What has been happening for the last several decades, however, is warming caused by increased greenhouse gasses in the Earth's atmosphere, as predicted over 100 years ago. The rate of warming is 0.2 degrees Celsius per decade, far faster than it's been for the thousands of years prior to the industrial revolution.
I've seen many posts claiming that the world has been cooling since 1998. And there are the ones with links to pictures to a handful of weather stations that are in new parking lots or next to a newly installed air conditioner, claiming that the observed warming is due to an urban heat island effect. Then there are those that claim any increase in sea ice extent means that ice is not melting, even though sea ice extent measures only the surface area of ice, and the volume of ice has been decreasing for the last several decades.
Maybe now we can at least accept that the warming of the past several decades is real. This warming effect due to increased carbon dioxide in the atmosphere was predicted over 100 years ago.
Why ask about it on Slashdot? We'll all say information wants to be free and we don't believe in imaginary property. Oh, wait, you said big corporations are ripping off your stuff? OFF WITH THEIR HEADS1!!11!!1!
This is the nitpicking that ID proponents are famous for. They think that by pointing out a shortcoming of evolution, for example, something that evolution has yet to explain, that they can say that the theory of evolution itself is flawed. In any science, there are always phenomena that remain unexplained. In physics, we cannot reconcile relativity and quantum mechanics. I don't see anyone pointing out that shortcoming as a reason for teaching alternatives to relativity or quantum mechanics to students.
If they want to show that evolution is flawed, they would need to make an observation that is inconsistent with the theory. For example, if in one generation several new genes never before seen suddenly appeared in a species, that would be evidence that some intelligent agent designed the genes and inserted them into DNA, and that they did not arise from mutations. But when we measure genetic changes, they always appear to be random mutations, and the rate of genetic change over millions of years matches up closely with the rate expected by those random mutations, exactly as expected from the theory of evolution.
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No, asteroids have been hitting the Earth for millions of years. This proves beyond a shadow of a doubt there is absolutely nothing to worry about!
The great thing is that we can simply measure the warming of the planet and determine the effects. We're running the experiment right now. Anyway, as far as we know, even if the climate sensitivity is as low as 1.2 degrees Celsius, we still need to be doing more to reduce carbon dioxide emissions than we have been doing. According to the IPCC, the climate sensitivity is between 1.1 and 6.4 degrees Celsius. Whatever it is, we will need to reduce carbon dioxide emissions to prevent warming in excess of 2 degrees Celsius. After we reduce emissions some, we'll get more data in so we can fine tune our policies.
I have the equivalent of an AS degree in physics, and you have no idea what you're talking about. The Earth most definitely is in thermal equilibrium. Take, for example, these notes from the University of Oregon that states that "earth wants to stay in thermal equilibrium". If we produced thousands of petawatts of power from fusion, we could warm the Earth. The Earth would respond by emitting more radiation and cooling down. What is happening instead is that increased greenhouse gasses are causing less radiation to be radiated into space, causing warming. It's very simple physics, and all these effects were predicted by Arrhenius over 100 years ago.
The statement you are referring to is that over a recent ten-year period, there is just over a 5% chance that the warming over that ten-year period could possibly have been due to chance alone. In other words, there is less than a 95% chance that the warming was due to increased carbon dioxide in the atmosphere. If you take longer time periods, we are more than 95% sure that the warming is not due to chance.
It's just the same as if you keep flipping a coin, and you get 7 heads in a row. There is a 1 in 64 probability for getting either 7 heads in a row or 7 tails in a row, so you can't determine whether a coin is fair or not to a 95% statistical significance by flipping it only 7 times. If you flip it 100 times and it comes up heads 70 times, however, it's almost certain the coin isn't fair. That's what TFA is saying. We're sure the warming is not a chance occurrence. It is undeniable that the warming trend is not just a random fluctuation. The Earth really is warming.
I understand chaos. A butterfly flapping its wings could cause a dramatic change in weather. It would not change the climate. Changing the climate would require massive amounts of energy to cause the climate to shift to a new state. This is exactly the effect doubling the concentration of carbon dioxide has. It causes the Earth to radiate less heat into space, so the Earth warms to a new equilibrium temperature. Jeez, some people just don't grok physics, do they?
NASA scientists have probably just made up this asteroid impact so they can get rich by getting grants to study the chance of impact and what to do about it. Politicians will love it because it gives them an excuse to raise taxes to deal with the possible impact. Of course, asteroids have been impacting the Earth for millions of years, so it can't possibly be anything to worry about. They should prove that we can avoid the impact before they spend any money on attempting to avoid it. We don't even know if the impact will happen, because multiple orbital bodies are a chaotic system, so we can't possibly predict where they'll be in 172 years.
There's not enough land to plant that many trees. Each human being emits about six tons of carbon dioxide each year on average. Where is each person going to put six tons of trees per year?
What makes you say climate is chaotic? Weather is certainly chaotic, because a slight change in initial conditions could cause a large change a few weeks from now. A slight change in wind direction today could mean that Chicago sees sunny weather next week instead of a rain storm.
But climate doesn't work that way. The climate remains stable unless conditions change fairly dramatically. For example, predictable changes in the Earth's orbit cause ice ages and interglacial periods. Why would you say the climate is chaotic? Does it have a sensitivity to initial conditions?
I don't understand what your point is. To what trend are you referring? Are you saying that it was warmer in the past, so we don't have to worry about warming?
No, I have no doubt at all. The problem is that whether the warming took place over 100 years or 1000 years, they all appear as vertical lines. A graph of a million years is useless to look at rates of warming over decades.
Why wouldn't we simply fail to reduce carbon dioxide emissions if we couldn't generate enough power from non-emitting sources? I don't see anyone making it illegal to meet energy demand, so it doesn't seem like anyone is proposing energy rationing.
Sorry, I left out the rate, which should be 0.2 degrees Celsius per decade.
Sorry, I don't pay much attention to sensationalist media. They tend to report on either one extreme or the other, or cover both extremes and not the middle for what they call "balance". I read what scientists say will be the effects of global warming. I try to watch their lectures to the public, which are explained well enough for non-climatologists to understand and not sensationalized and distorted by the media.
You forgot... "But it's been dripping for years and we've been okay. I'll show you this nice graph showing that the water level has remained low for years! It doesn't matter that I just put $50,000 in cash down there and the pipe just burst." Oh, and, "You have to prove to me that turning off the water at the water main will help even before I undertake such a drastic action that will shut off all the water to my house!"
I don't think anyone is actually worried about a runaway greenhouse effect on Earth. We're working on reducing carbon dioxide emissions to reduce warming, not to prevent a runaway effect. I think you've been reading too many sensationalist media articles.
So there can't be any convincing evidence without a controlled experiment? I wonder how geologists and astronomers work, then...
Anyway, what's so "drastic" about increasing energy efficiency and increasing production of alternative energy sources? I think you're being a bit... alarmist.
Who is proposing "global power rationing"? Generating biofuels will not take much of a chunk out of fossil fuel use, but it's needed to power large aircraft and ships if we're to reduce carbon dioxide emissions to below 20% of current levels.
It's not supposed to induce a sense of panic. It's supposed to explain why it would be a good idea to reduce carbon dioxide emissions. It will save money in the long run. It's a very reasonable, logical decision, not an emotional, panic-stricken knee jerk reaction.
The current rate of warming is 0.2 degrees Celcius. On any graph of temperatures going back millions of years, the temperature increase over the past several decades appears as a vertical line. To predict the rate of warming over the next century, it would be more informative to use a graph of the past century or so.
Millions of years ago, a warmer climate might have been a good thing overall. But warmer temperatures and rising sea level in the 21st century will cost trillions of dollars.
But there's no proposal to "change our entire civilization". All we need to do is cut net carbon dioxide emissions. We can do this by increasing energy efficiency, building nuclear power plants and solar power plants, and manufacturing biofuels. I can understand why so many people want to deny global warming when their lifestyle is at stake, but it isn't.
But the rate of warming has recently increased dramatically. The slow warming that ended the last ice age was due to changes in the Earth's orbit. What has been happening for the last several decades, however, is warming caused by increased greenhouse gasses in the Earth's atmosphere, as predicted over 100 years ago. The rate of warming is 0.2 degrees Celsius per decade, far faster than it's been for the thousands of years prior to the industrial revolution.
I've seen many posts claiming that the world has been cooling since 1998. And there are the ones with links to pictures to a handful of weather stations that are in new parking lots or next to a newly installed air conditioner, claiming that the observed warming is due to an urban heat island effect. Then there are those that claim any increase in sea ice extent means that ice is not melting, even though sea ice extent measures only the surface area of ice, and the volume of ice has been decreasing for the last several decades.
Maybe now we can at least accept that the warming of the past several decades is real. This warming effect due to increased carbon dioxide in the atmosphere was predicted over 100 years ago.
Why ask about it on Slashdot? We'll all say information wants to be free and we don't believe in imaginary property. Oh, wait, you said big corporations are ripping off your stuff? OFF WITH THEIR HEADS1!!11!!1!
This is the nitpicking that ID proponents are famous for. They think that by pointing out a shortcoming of evolution, for example, something that evolution has yet to explain, that they can say that the theory of evolution itself is flawed. In any science, there are always phenomena that remain unexplained. In physics, we cannot reconcile relativity and quantum mechanics. I don't see anyone pointing out that shortcoming as a reason for teaching alternatives to relativity or quantum mechanics to students.
If they want to show that evolution is flawed, they would need to make an observation that is inconsistent with the theory. For example, if in one generation several new genes never before seen suddenly appeared in a species, that would be evidence that some intelligent agent designed the genes and inserted them into DNA, and that they did not arise from mutations. But when we measure genetic changes, they always appear to be random mutations, and the rate of genetic change over millions of years matches up closely with the rate expected by those random mutations, exactly as expected from the theory of evolution.