Hot answers tagged climate-science
8
No, it is not possible that nuclear fission is responsible for climate change. So although it's theoretically possible that we could do enough nuclear fission to raise the global heat content of the earth significantly, in reality, we've done very little nuclear fission industrially, and it's a tiny tiny contribution.
First, remember that burning fossil ...
6
To start with, I need to write a list of assumptions that are at play, and numerous disclaimers are needed. Firstly, the IPCC scientists don't say this follows a $ln$ function at all. They say it follows whatever their computer models says it follows. This is only a first order solution. Assumptions begin here:
We are considering one gas
We are only ...
5
What you are talking about is called a combined cycle engine. They are commonplace in stationary power generation, i.e. utility-scale electricity generation. There has even been some talk of combined cycle engines in cars.
As pointed out in the answer by dmckee, the reason this hasn't been widely applied in cars is that no one has demonstrated an ...
5
Yes, of course, the suntan/sunburn depends on the overall energy in UV radiation coming from the Sun to one's skin and this quantity is virtually unchanged in the glaciation cycles, at least if you average it over seasons. What primarily matters is the angle between the Sun rays and the plane of the skin; and the angle between the Sun rays and the plane of ...
4
The article you quoted frankly reads very poorly. It quotes a lot of stuff without once noting that greenhouse effects absolutely are real and critical to the earth being habitable. I don't know who this fellow is, but if he posted here directly I'd give it an instant negative vote.
You, sir, I'm giving a thumbs up for taking the trouble to ask in a forum ...
4
The most important physics with respect to cloud formation happens in what is called the Atmospheric Boundary Layer (ABL). A lot of research is done in this field, since the effects of clouds is the major source of incertainty in all climate prediction models.
To get some sort of cloud formation, in my opinion you would need to have some kind of ABL inside ...
4
Assuming it's a cloudless day, then yes you will get a sunburn just as you would today. Sunburn is caused by the intensity of ultraviolet light, and this didn't change (much) during the ice age. The external temperature makes no difference: it's just the uv intensity that matters. Any skier can tell you that :-)
Actually, now I think about it, it's possible ...
4
I would add a humidity sensor, as water vapor is the strongest green house gas .
This graph may suggest other gases
>
Breakdown of the anthropic greenhouse gas emissions by gas. Source : IPCC, 2007
Here is an article on halocarbons.
3
The third equation is just a sum of the two first:
$$
S+\lambda A=G \Rightarrow S=-\lambda A+G\\
\lambda G=2\lambda A \Rightarrow 0=2\lambda A-\lambda G
$$
Add them up and get:
$$
S=-\lambda A+2\lambda A+G-\lambda G=\lambda A+(1-\lambda)G
$$
which is the third equation. So, still only two independent equations and two unknowns.
3
Let's look a bit closer at the claims of Doug Cotton, and of Claes Johnson, whose work Doug relies upon. It's important because this is one of the strongest claims made by those who choose to reject the notion of anthropogenic climate change.
Here's the core claim, from Doug Coton:
The assumption is made that so-called "backradiation" from a cold ...
3
I think, this question more specific to meteorology and climatology than pure physics, but definitely can be answered
in physics terms with some meteorological comments. Thereby, your question can be redefined as: How relative humidity, temperature, pressure and height relates to level of precipitation?
Firstly, we should look at basic ideas to understand ...
3
If humans were able to catch all sun energy reaching the earth for their use, will the climate change? It would depend on how much of that energy ends up as heat. Currently, a proportion is reflected back into space: the Earth has a non-zero albedo - it is not perfectly black, and does reflect back into space. Pretty much all the rest does end up as heat.
...
3
Climate modelling is a giant science of its own, and the proportion of CFD/statistics depends on the particular model.
In general, what models do is first a simple (often uncompressable) large-scale CFD to advect the scalar fields and then apply a bunch of subrutines simulating small scale and more complex processes, like radiation transfers, heat transfers, ...
2
To make things simple you want to compare two atmospheres that are identical, except that one has infinitessimally more of some IR absorber. In the second case, some IR photons that were traveling upwards are absorbed, and thermalized (i.e. the energy is transferred to the surrounding gas molecules, before being re-emitted). The IR photons are basically ...
2
The seasons on earth are caused by the rotation of the earth around the sun in addition with the inclination of the axis of the earth. This causes the angle of incident sunlight to be lower in winter and higher in summer.
Now, the inclination of the axis of the earth is pretty constant. But if that axis would shift in some funny way, you could have any ...
2
The radiative portion is actually pretty straightforward. For the absorption of sunlight
you multiply the strength of the sun (usually taken as 1000 watt/meter**2 at sea level by
1 minus the albedo, and multiply by the cosine of the angle. For IR, you need to know the
emissivity (but for most surfaces .95 to 1 can be assumed), and use the Stefan Bolzmann ...
2
There CERES satellite has been measuring light reflected from Earth. In principle the raw data is available from NASA though I imagine some work will be necessary to process it.
1
The average temperature will be a little higher and more stable.
Stable because of increased heat capacity.
Higher because humid air will absorb more solar energy.
But I believe that these real changes in temperature will be negligible compared to temperature changes reported by the workers in the office. Their cooling will become slower (because the ...
1
This is a rather more simplistic argument than Anna's, but it might make an impression on your friend.
The Earth and the Moon receive the same amount of energy (per square metre) from the Sun, but the average temperature of the Moon about -35C. So it's pretty obvious that the atmosphere of the Earth raises its temperature 50 or so degrees. I suppose you ...
1
Fortunately our puny nuclear bombs are no match for the mighty volcano.
Even Mt St Helens, a pretty pathetic volcano by historic standards, put out about the same energy as the largest bomb tested. It had a much greater effect on the atmosphere by putting an aerosol of nasty greenhouse chemicals as well as a few 10^9 m^3 of ash and dust.
In general tests ...
1
The first thing to note is that we will not burn all accessible fossil fuels, at least not within the next couple of hundred years, because to do so would be to pretty much destroy human civilisation. So one of the presuppositions in the question is incorrect.
And now to the effect of the rate of release.
Greenhouse gas concentrations are a stock problem, ...
1
Taking the question at face value, the answer is yes. In order to collect all the solar energy arriving at the Earth you would have to completely cover its surface in solar panels. These solar panels would have to encase the entire atmosphere, because otherwise some energy would be reflected by clouds. This would leave no energy left to drive ...
1
The answer is straightforward.
The solution to the equations of radiative transfer is not a logarithmic function. The equations have to be numerically solved to get the answer.
The equations of radiative transfer are based on fundamental physics and are well-proven by experimental evidence.
For the equations, see Understanding Atmospheric Radiation and ...
1
N-body problem should pretty well cover this. Solving the almost intractable problem of three gravitating mass goes back to Newton.
http://en.wikipedia.org/wiki/N-body_problem#Three-body_problem
Quoting from the above article: "Specific solutions to the three-body problem result in chaotic motion with no obvious sign of a repetitious path."
So assuming ...
1
There's no simple and surely no analytic function describing the daily cycles of the temperature. It's not hard to see why: while you could add some higher harmonics etc., the actual process clearly contains many unsmooth points. During the day, when the Sun is visible, the temperature typically increases, and the rate of increase is maximum around the noon. ...
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