Those periods were significantly below current day temperatures. Why are you choosing to say exactly the opposite of what is the case? Wrong about what exactly? Lag is irrelevant. I've said why. So fundamentally your position boils down to saying scientific fact is wrong. Well good luck with that one but I can tell you it won't get you anywhere.
As shown in all the raw data, the medieval warm period was significantly WARMER than it is today. You can choose to ignore the charts and data, but the truth stands. Why do you think Greenland is called "Green Land"? The Viking were growing grains such barley there during the Medieval Warm period. In England during this time grapes were grown for wine? How do you explain this unless the world was fundamentally warmer in 900AD to 1200AD. The bottom line is that man-made warming caused by CO2 does not supported by scientific evidence. The reality is that man should be more concerned with natural global cooling and take steps to prepare for it.
Doesn't matter what happened back then. They were not pumping huge amounts of a GHG into the air like we are now. Idiot.
"The oceans contain 37,400 billion tons (GT) of suspended carbon, land biomass has 2000-3000 GT. The atmosphere contains 720 billion tons of CO2 and humans contribute only 6 GT additional load on this balance." http://noconsensus.wordpress.com/2008/12/06/ten-global-warming-myths/ So basically man's contribution is the size of a pixel on a 60 inch high resolution monitor. "In the last 100 years it is said that CO2 increased from 270 to 388 parts per million. This is an increase of 0.000118 or 0.0118%."
CO2 and other greenhouse gases both warm and cool you idiot... learn some science. I have presented links and papers showing that many times. Some of the links are from NASA science. the unanswered question right now is that when you add greenhouse gases do they net warm or net cool. Why don't you try and actually present some science to support your belief that adding more co2 creates warming in our current environment. I have written many times... after reading many papers on the subject... I suspect that intially co2 warms via trapping heat but as more co2 gets added it starts repelling more heats than it additionally traps. That CO2 is also coolant has been proven in recent NASA experiments.
Here is your proof. That you will ignore. Surface measurements of downward longwave radiation The increase in atmospheric CO2 and other greenhouse gases has increased the amount of infrared radiation absorbed and re-emitted by these molecules in the atmosphere. The Earth receives energy from the Sun in the form of visible light and ultraviolet radiation, which is then re-radiated away from the surface as thermal radiation in infrared wavelengths. Some of this thermal radiation is then absorbed by greenhouse gases in the atmosphere and re-emitted in all directions, some back downwards, increasing the amount of energy bombarding the Earth's surface. This increase in downward infrared radiation has been observed through spectroscopy, which measures changes in the electromagnetic spectrum. Satellite measurements of outgoing longwave radiation The increased greenhouse effect is also confirmed by NASA's IRIS satellite and the Japanese Space Agency's IMG satellite observing less longwave leaving the Earth's atmosphere. ture' indicates equivalent blackbody temperature (Harries 2001). The increased energy reaching the Earth's surface from the increased greenhouse effect causes it to warm. So how do we quantify the amount of warming that it causes? Radiative Transfer Models Radiative transfer models use fundamental physical equations and observations to translate this increased downward radiation into a radiative forcing, which effectively tells us how much increased energy is reaching the Earth's surface. Studies have shown that these radiative transfer models match up with the observed increase in energy reaching the Earth's surface with very good accuracy (Puckrin 2004). Scientists can then derive a formula for calculating the radiative forcing based on the change in the amount of each greenhouse gas in the atmosphere (Myhre 1998). Each greenhouse gas has a different radiative forcing formula, but the most important is that of CO2: dF = 5.35 ln(C/Co) Where 'dF' is the radiative forcing in Watts per square meter, 'C' is the concentration of atmospheric CO2, and 'Co' is the reference CO2 concentration. Normally the value of Co is chosen at the pre-industrial concentration of 280 ppmv. Now that we know how to calculate the radiative forcing associated with an increase in CO2, how do we determine the associated temperature change? Climate sensitivity As the name suggests, climate sensitivity is an estimate of how sensitive the climate is to an increase in a radiative forcing. The climate sensitivity value tells us how much the planet will warm or cool in response to a given radiative forcing change. As you might guess, the temperature change is proportional to the change in the amount of energy reaching the Earth's surface (the radiative forcing), and the climate sensitivity is the coefficient of proportionality: dT = λ*dF Where 'dT' is the change in the Earth's average surface temperature, 'λ' is the climate sensitivity, usually with units in Kelvin or degrees Celsius per Watts per square meter (°C/[W/m2]), and 'dF' is the radiative forcing. So now to calculate the change in temperature, we just need to know the climate sensitivity. Studies have given a possible range of values of 2-4.5°C warming for a doubling of CO2 (IPCC 2007). Using these values it's a simple task to put the climate sensitivity into the units we need, using the formulas above: λ = dT/dF = dT/(5.35 * ln[2])= [2 to 4.5°C]/3.7 = 0.54 to 1.2°C/(W/m2) Using this range of possible climate sensitivity values, we can plug λ into the formulas above and calculate the expected temperature change. The atmospheric CO2 concentration as of 2010 is about 390 ppmv. This gives us the value for 'C', and for 'Co' we'll use the pre-industrial value of 280 ppmv. dT = λ*dF = λ * 5.35 * ln(390/280) = 1.8 * λ Plugging in our possible climate sensitivity values, this gives us an expected surface temperature change of about 1â2.2°C of global warming, with a most likely value of 1.4°C. However, this tells us the equilibrium temperature. In reality it takes a long time to heat up the oceans due to their thermal inertia. For this reason there is currently a planetary energy imbalance, and the surface has only warmed about 0.8°C. In other words, even if we were to immediately stop adding CO2 to the atmosphere, the planet would warm another ~0.6°C until it reached this new equilibrium state (confirmed by Hansen 2005). This is referred to as the 'warming in the pipeline'. Of course this is just the temperature change we expect to observe from the CO2 radiative forcing. Humans cause numerous other radiative forcings, both positive (e.g. other greenhouse gases) and negative (e.g. sulfate aerosols which block sunlight). Fortunately, the negative and positive forcings are roughly equal and cancel each other out, and the natural forcings over the past half century have also been approximately zero (Meehl 2004), so the radiative forcing from CO2 alone gives us a good estimate as to how much we expect to see the Earth's surface temperature change. Figure 4: Global average radiative forcing in 2005 (best estimates and 5 to 95% uncertainty ranges) with respect to 1750 (IPCC AR4). We can also calculate the most conservative possible temperature change in response to the CO2 increase. Some climate scientists who are touted as 'skeptics' have suggested the actual climate sensitivity could be closer to 1°C for a doubling of CO2, or 0.27°C/(W/m2). Although numerous studies have ruled out climate sensitivity values this low, it's worth calculating how much of a temperature change this unrealistically low value would generate. Using the same formulas as above, dT = 1.8 * λ = 1.8 * 0.27 = 0.5°C. Therefore, even under this ultra-conservative unrealistic low climate sensitivity scenario, the increase in atmospheric CO2 over the past 150 years would account for over half of the observed 0.8°C increase in surface temperature. Conservation of Energy Huber and Knutti (2011) published a paper in Nature Geoscience, Anthropogenic and natural warming inferred from changes in Earthâs energy balance. They take an approach in this study which utilizes the principle of conservation of energy for the global energy budget using the measurements discussed above, and summarize their methodology: "We use a massive ensemble of the Bern2.5D climate model of intermediate complexity, driven by bottom-up estimates of historic radiative forcing F, and constrained by a set of observations of the surface warming T since 1850 and heat uptake Q since the 1950s....Between 1850 and 2010, the climate system accumulated a total net forcing energy of 140 x 1022 J with a 5-95% uncertainty range of 95-197 x 1022 J, corresponding to an average net radiative forcing of roughly 0.54 (0.36-0.76)Wm-2." Essentially, Huber and Knutti take the estimated global heat content increase since 1850, calculate how much of the increase is due to various estimated radiative forcings, and partition the increase between increasing ocean heat content and outgoing longwave radiation. The authors note that more than 85% of the global heat uptake (Q) has gone into the oceans, including increasing the heat content of the deeper oceans, although their model only accounts for the upper 700 meters. As expected, Huber and Knutti find that greenhouse gases contributed to substantial warming since 1850, and aerosols had a significant cooling effect: "Greenhouse gases contributed 1.31°C (0.85-1.76°C) to the increase, that is 159% (106-212%) of the total warming. The cooling effect of the direct and indirect aerosol forcing is about -0.85°C (-1.48 to -0.30°C). The warming induced by tropospheric ozone and solar variability are of similar size (roughly 0.2°C). The contributions of stratospheric water vapour and ozone, volcanic eruptions, and organic and black carbon are small." Since 1950, the authors find that greenhouse gases contributed 166% (120-215%) of the observed surface warming (0.85°C of 0.51°C estimated surface warming). The percentage is greater than 100% because aerosols offset approximately 44% (0.45°C) of that warming. "It is thus extremely likely (>95% probability) that the greenhouse gas induced warming since the mid-twentieth century was larger than the observed rise in global average temperatures, and extremely likely that anthropogenic forcings were by far the dominant cause of warming. The natural forcing contribution since 1950 is near zero." A number of studies have used a variety of statistical and physical approaches to determine the contribution of greenhouse gases and other effects to the observed global warming, like Huber and Knutti. And like Huber and Knutti, they find that greenhouse gases have caused more warming than has been observed, because other factors have had a net cooling effect over the past century (Figure 5).
First of all stu, you ignorant fool, greenhouse gases warm and cool. What science does not know right now is if add more CO2 or more water vapor to this environment warms or cools. That is where a lot of research is being done right now. NASA recently called CO2 a powerful coolant and a thermostat in this study. Why don't you try and actually present some science to support your belief that adding more co2 creates warming in our current environment.
1. You are so ignorant and such a liar I have shown you this quote from the recent nasa experiment a dozen times... where recently NASA has stated that CO2 is a coolant and that it repels the suns energy... (which is a cooling effect on the planet) And don't give that crap about you don't care about what happens in the upper atmosphere because the scientist making the climate budgets certainly do... and blocking the suns energy is a cooling effect. http://science.nasa.gov/science-news/science-at-nasa/2012/22mar_saber/ âCarbon dioxide and nitric oxide are natural thermostats,â explains James Russell of Hampton University, SABERâs principal investigator. âWhen the upper atmosphere (or âthermosphereâ) heats up, these molecules try as hard as they can to shed that heat back into space.â Thatâs what happened on March 8th when a coronal mass ejection (CME) propelled in our direction by an X5-class solar flare hit Earthâs magnetic field. (On the âRichter Scale of Solar Flares,â X-class flares are the most powerful kind.) Energetic particles rained down on the upper atmosphere, depositing their energy where they hit. The action produced spectacular auroras around the poles and significant1 upper atmospheric heating all around the globe. âThe thermosphere lit up like a Christmas tree,â says Russell. âIt began to glow intensely at infrared wavelengths as the thermostat effect kicked in.â For the three day period, March 8th through 10th, the thermosphere absorbed 26 billion kWh of energy. Infrared radiation from CO2 and NO, the two most efficient coolants in the thermosphere, re-radiated 95% of that total back into space. 2. Clouds closely related to water vapor... both reflect some heat down and reflect sun light back out. NASA is studying their overall net effect in our current environment. Recent studies have shown they have big cooling effect in the tropics. Which makes sense to anyone ever under clouds in the tropics. here is more info... http://www.sjsu.edu/faculty/watkins/cloudiness.htm J.R. Houghton expressed the situation as follows: Clouds are, in fact, probably the dominant influence in the radiative budget of the lower atmosphere but adequately taking them into account raises many problems [â¦] The Physics of Atmospheres, p. 41. Note that recent studies claim that CO2 increases its impact by increasing clouds. So right their you agw nutter bozos should understand... CO2 can also cool by making more clouds. 3. Water Vapor can have a significant cooling effect through evaporation. Some studies show the effect is larger than its warming effect. summary... Scientist are working on improving their radiative budgets right now. Its all guess work... because clouds and other effects have so far proven impossible to model. So... agw drone trolls ... let me know when you have a radiation budget that can account for all these variables and more... maybe then you will develop a working climate model. Til then you can't tell me whether adding a greenhouse gas warms or cools.
No, you have no science proving CO2 cools. CO2 warms the planet. That's why it's called a GHG. Idiot.