Some climate change skeptics dispute the so-called ‘greenhouse effect’, which keeps thesurface temperature of the Earth approximately 33 degrees C warmer than it would be if there were no greenhouse gases in the atmosphere. In other words, without thegreenhouse effect, the Earth would be largely uninhabitable. How do we know for sure this effect is real? The principle is demonstrated through basic physics, because a bare rock orbiting the sun at the distance of the Earth should be far colder than the Earth actually is. The explanation for this observation was based on the work of John Tyndall, who discovered in 1859 that several gases, including carbon dioxideand water vapour, could trap heat. This was the first evidence for what we know now asgreenhouse gases. Then, towards the end of the same century, a Swedish scientist named Svante Arrhenius proved the relationship between greenhouse gas concentrations and surface temperatures. Empirical Evidence for the Greenhouse Effect We only have to look to our moon for evidence of what the Earth might be like without anatmosphere that sustained the greenhouse effect. While the moon’s surface reaches 130 degrees C in direct sunlight at the equator (266 degrees F), when the sun ‘goes down’ on the moon, the temperature drops almost immediately, and plunges in several hours down to minus 110 degrees C (-166F). Since the moon is virtually the same distance from the sun as we are, it is reasonable to ask why at night the Earth doesn’t get as cold as the moon. The answer is that, unlike the Earth, the moon has no water vapour or other greenhouse gases, because of course it has no atmosphere at all. Without our protective atmosphere and the greenhouse effect, the Earth would be as barren as our lifeless moon; without the heat trapped overnight in the atmosphere (and in the ground and oceans) our nights would be so cold that few plants or animals could survive even a single one. The most conclusive evidence for the greenhouse effect – and the role CO2 plays – can be seen in data from the surface and from satellites. By comparing the Sun’s heatreaching the Earth with the heat leaving it, we can see that less long-wave radiation (heat) is leaving than arriving (and since the 1970s, that less and less radiation is leaving the Earth, as CO2 and equivalents build up). Since all radiation is measured by its wavelength, we can also see that the frequencies being trapped in the atmosphere are the same frequencies absorbed by greenhouse gases. Disputing that the greenhouse effect is real is to attempt to discredit centuries of science, laws of physics and direct observation. Without the greenhouse effect, we would not even be here to argue about it.
who here is disputing the greenhouse effect? we are talking about a complex system. there probably is a greenhouse effect coming out of an ice age. But at some point the negative feedbacks kick in to prevent a runaway greenhouse effect where all the gases are evaporated. This is a complex environment with negative feedback systems no one really knows what adding man made co2 does, if anything. We do know co2 levels trails temperature up and down.
The effect of adding man-made CO2 is predicted in the theory of greenhouse gases. This theory was first proposed by Swedish scientist Svante Arrhenius in 1896, based on earlier work by Fourier and Tyndall. Many scientist have refined the theory in the last century. Nearly all have reached the same conclusion: if we increase the amount of greenhouse gases in the atmosphere, the Earth will warm up. What they don’t agree on is by how much. This issue is called ‘climate sensitivity’, the amount the temperatures will increase if CO2 is doubled from pre-industrial levels.Climate models have predicted the least temperature rise would be on average 1.65°C (2.97°F) , but upper estimates vary a lot, averaging 5.2°C (9.36°F). Current best estimates are for a rise of around 3°C (5.4°F), with a likely maximum of 4.5°C (8.1°F). What Goes Down… The greenhouse effect works like this: Energy arrives from the sun in the form of visible light and ultraviolet radiation. The Earth then emits some of this energy as infrared radiation. Greenhouse gases in the atmosphere 'capture' some of this heat, then re-emit it in all directions - including back to the Earth's surface. Through this process, CO2 and other greenhouse gases keep the Earth’s surface 33°Celsius (59.4°F) warmer than it would be without them. We have added 42% moreCO2, and temperatures have gone up. There should be some evidence that links CO2 to the temperature rise. So far, the average global temperature has gone up by about 0.8 degrees C (1.4°F): "According to an ongoing temperature analysis conducted by scientists atNASA’s Goddard Institute for Space Studies (GISS)…the average global temperature on Earth has increased by about 0.8°Celsius (1.4°Fahrenheit) since 1880. Two-thirds of the warming has occurred since 1975, at a rate of roughly 0.15-0.20°C per decade." The temperatures are going up, just like the theory predicted. But where’s the connection with CO2, or other greenhouse gases like methane, ozone or nitrous oxide? The connection can be found in the spectrum of greenhouse radiation. Using high-resolution FTIR spectroscopy, we can measure the exact wavelengths of long-wave (infrared) radiation reaching the ground. Figure 1: Spectrum of the greenhouse radiation measured at the surface. Greenhouse effect from water vapour is filtered out, showing the contributions of other greenhouse gases (Evans 2006). Sure enough, we can see that CO2 is adding considerable warming, along with ozone(O3) and methane (CH4). This is called surface radiative forcing, and the measurements are part of the empirical evidence that CO2 is causing the warming. ...Must Go Up How long has CO2 been contributing to increased warming? According to NASA, “Two-thirds of the warming has occurred since 1975”. Is there a reliable way to identify CO2’s influence on temperatures over that period? There is: we can measure the wavelengths of long-wave radiation leaving the Earth (upward radiation). Satellites have recorded the Earth's outbound radiation. We can examine the spectrum of upward long-wave radiation in 1970 and 1997 to see if there are changes. Figure 2: Change in spectrum from 1970 to 1996 due to trace gases. 'Brightness temperature' indicates equivalent blackbody temperature (Harries 2001). This time, we see that during the period when temperatures increased the most, emissions of upward radiation have decreased through radiative trapping at exactly the same wavenumbers as they increased for downward radiation. The same greenhouse gases are identified: CO2, methane, ozone etc. The Empirical Evidence As temperatures started to rise, scientists became more and more interested in the cause. Many theories were proposed. All save one have fallen by the wayside, discarded for lack of evidence. One theory alone has stood the test of time, strengthened by experiments. We know CO2 absorbs and re-emits longwave radiation (Tyndall). The theory ofgreenhouse gases predicts that if we increase the proportion of greenhouse gases, more warming will occur (Arrhenius). Scientists have measured the influence of CO2 on both incoming solar energy and outgoing long-wave radiation. Less longwave radiation is escaping to space at the specific wavelengths of greenhouse gases. Increased longwave radiation is measured at the surface of the Earth at the same wavelengths. These data provide empirical evidence for the predicted effect of CO2.
Wait a minute. Did jerm actually say this? But at some point the negative feedbacks kick in to prevent a runaway greenhouse effect where all the gases are evaporated.
you are a moron troll with no science fc. you still refuse to produce a list of scientists who state man made co2 causes warming... and you refuse to provide the per review papers.... we don't live in a static laboratory... with live in a complex environment with negative and positive feedbacks. this is a good summary of the recent papers I have presented here over the last few years. http://www.acs.org/content/acs/en/c...cenarratives/its-water-vapor-not-the-co2.html There is also a possibility that adding more water vapor to the atmosphere could produce a negative feedback effect. This could happen if more water vapor leads to more cloud formation. Clouds reflect sunlight and reduce the amount of energy that reaches the Earth’s surface to warm it. If the amount of solar warming decreases, then the temperature of the Earth would decrease. In that case, the effect of adding more water vapor would be cooling rather than warming. But cloud cover does mean more condensed water in the atmosphere, making for a stronger greenhouse effect than non-condensed water vapor alone – it is warmer on a cloudy winter day than on a clear one. Thus the possible positive and negative feedbacks associated with increased water vapor and cloud formation can cancel one another out and complicate matters. The actual balance between them is an active area of climate science research.
jem, If you accept that water vapor is a greenhouse gas, then my question is: if one were to hold all other climate variables constant, and increase the amount of water vapor in the atmosphere, could we expect the atmosphere to warm?
But that's not happening. You apparently are not paying attention to the volumes of authoritative science I have presented. Yes if the queen had balls she could be king. If you weren't a libtardarian you might understand climate science. If unicorns had wings they could fly over Al Gore's house and shit on it. You have quite the imagination.
Cost of not acting on climate change $44 TRILLION: Citi http://www.cnbc.com/2015/08/18/cost-of-not-acting-on-climate-change-44-trillion-citi.html
How come we did not see any science. Could citi be talking their book? Is citi planning on being one of the owners of a carbon exchange. http://www.microcapital.org/microca...y-mongolian-microfinance-institution-xacbank/ XacBank, a Mongolian community development institution, will issue microloans to fund the purchase and installation of the appliances. The reductions in household emissions earned by the use of these energy efficient fixtures will be assigned to MEC. In turn, MEC will quantify, aggregate and sell the credits to Citi Microfinance, who will monetize them on the open market through the Environmental Products Trading and Organization Team. An unspecified portion of the profit from Citi’s carbon credit purchase will be disbursed by MEC to XacBank so that the MFI can expand its clean energy program and increase access to clean energy loans. The program is currently being approved and registered by the Clean Development Mechanism, a program of the United Nations Framework Convention on Climate Change (UNFCCC).
you have presented exactly zero peer reviewed science and you have not even provided a list of scientists who themselves state man made co2 is causing warming. The reason is... is that there is no science saying man made co2 causes warming... that was not based on now failed models. you can bullshit all you want.. but til you produce peer reviewed science... its clear you are bullshitting and you like juvenile gifs.