Global warming scepticism

your comments are nonsensical, i didn't say anything about 85 degrees

carbon dioxide lets light energy in, but doesn't let all of the heat energy out


How do we know that humans are the major cause of global warming?

The Fourth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) states: it is a greater than a 90 percent certainty that emissions of heat-trapping gases from human activities have caused “most of the observed increase in globally averaged temperatures since the mid-20th century.” We all know that warming—and cooling—has happened in the past, and long before humans were around. Many factors (called “climate drivers&#8221 can influence Earth’s climate—such as changes in the sun’s intensity and volcanic eruptions, as well as heat-trapping gases in the atmosphere.

So how do scientists know that today’s warming is primarily caused by humans putting too much carbon in the atmosphere when we burn coal, oil, and gas or cut down forests?

There are human fingerprints on carbon overload. When humans burn coal, oil and gas (fossil fuels) to generate electricity or drive our cars, carbon dioxide is released into the atmosphere, where it traps heat. A carbon molecule that comes from fossil fuels and deforestation is “lighter” than the combined signal of those from other sources. As scientists measure the “weight” of carbon in the atmosphere over time they see a clear increase in the lighter molecules from fossil fuel and deforestation sources that correspond closely to the known trend in emissions.

Natural changes alone can’t explain the temperature changes we’ve seen. For a computer model to accurately project the future climate, scientists must first ensure that it accurately reproduces observed temperature changes. When the models include only recorded natural climate drivers—such as the sun’s intensity—the models cannot accurately reproduce the observed warming of the past half century. When human-induced climate drivers are also included in the models, then they accurately capture recent temperature increases in the atmosphere and in the oceans. When all the natural and human-induced climate drivers are compared to one another, the dramatic accumulation of carbon from human sources is by far the largest climate change driver over the past half century.

Lower-level atmosphere—which contains the carbon load—is expanding. The boundary between the lower atmosphere (troposphere) and the higher atmosphere (stratosphere) has shifted upward in recent decades. See the ozone FAQ for a figure illustrating the layers of the atmosphere. This boundary has likely changed because heat-trapping gases accumulate in the lower atmosphere and that atmospheric layer expands as it heats up (much like warming the air in a balloon). And because less heat is escaping into the higher atmosphere, it is likely cooling. This differential would not occur if the sun was the sole climate driver, as solar changes would warm both atmospheric layers, and certainly would not have warmed one while cooling the other.
Direct evidence of human contribution to atmospheric CO2

Carbon dioxide (CO2) is the main heat-trapping gas largely responsible for most of the average warming over the past several decades. To compare how CO2 stacks up in influence to the many other important heat-trapping gases contributing to climate change see the CO2 FAQ. There is a way that scientists can tease apart the atmospheric concentration of CO2 to see how much of the CO2 is from natural sources and how much is from combusted fossil fuel sources.

The atmospheric concentration of CO2 has increased from a pre-industrial era (AD 1000 – 1750) concentration of approximately 280 parts per million (ppm) to around 383 ppm, as measured at Mauna Loa, Hawaii in 2007. The carbon in the atmospheric CO2 contains information about its source, so that scientists can tell that fossil fuel emissions comprise the largest source of the increase since the pre-industrial era.

Here’s how scientists know. The same elements (i.e. same number of protons in the nucleus) with different mass numbers (arising from the different numbers of neutrons in the nucleus) are called isotopes. Each carbon molecule has six protons in the nucleus, but there are many different isotopes with varying numbers of neutrons in the nucleus.Carbon isotopes from different sources are “lighter” (high negative value) or heavier (lower negative value). For example, carbon from ocean is the standard with a value of “0” while carbon from fossil fuels ranges from -20 to -32. While atmospheric carbon has an average value of -5 to -9, it is becoming “lighter” over time as carbon from fossil fuels become more abundant in the atmosphere (Figure 1).

Figure 1. Direct Evidence of Fossil Fuel Derived CO2 in the Atmosphere



http://www.ucsusa.org/global_warming/science_and_impacts/science/human-contribution-to-gw-faq.html#.VgmOvkvIrJw

 

so how hot is CO2 when it receives light energy? Is it hotter than the sun? Still don't understand how you think CO2 can make the earth warmer. If it absorbs 85 degree light energy, it releases 85 degree light energy. How is CO2 responsible for a hotter earth? You haven't explained it. How do you??????


Edit, still no mention of the experiment that I posted. No comment?

 

post number 753 makes it all clear

it has already been refuted

 

no it doesn't, it doesn't answer my question to you. I asked you a question, I expect an answer not stats and someone else's interpretation of it. Answer the question. I see you can't walk the walk.

it was? where? post number.

 

here it is again, i'm betting you'll keep pretending not to understand


"There are human fingerprints on carbon overload. When humans burn coal, oil and gas (fossil fuels) to generate electricity or drive our cars, carbon dioxide is released into the atmosphere, where it traps heat. A carbon molecule that comes from fossil fuels and deforestation is “lighter” than the combined signal of those from other sources. As scientists measure the “weight” of carbon in the atmosphere over time they see a clear increase in the lighter molecules from fossil fuel and deforestation sources that correspond closely to the known trend in emissions."

 

how hot is the heat it traps? Can you answer? That has been my question and you avoid an answer.

 

That is not a scientific experiment.

 

it depends on the location

the 20th century average global temperature is 57°

Global Analysis - August 2015

Temperatures

In the atmosphere, 500-millibar height pressure anomalies correlate well with temperatures at the Earth's surface. The average position of the upper-level ridges of high pressure and troughs of low pressure—depicted by positive and negative 500-millibar height anomalies on the August 2015 and June–August 2015 maps—is generally reflected by areas of positive and negative temperature anomalies at the surface, respectively.



The combined average temperature over global land and ocean surfaces for August 2015 was 0.88°C (1.58°F) above the 20th century average of 15.6°C (60.1°F) and the highest August in the 136-year record. This value surpassed the previous record set in 2014 by 0.09°C (0.16°F). Most of the world's surface was substantially warmer than average and, in some locations, record warm during August 2015, contributing to the monthly global record warmth. This was the sixth month in 2015 that has broken its monthly temperature record (February, March, May, June, July, and August). August 2015 tied with January 2007 as the third warmest monthly departure from average for any of the 1628 months since records began in January 1880, behind February 2015 and March 2015 (+0.89°C / +1.60°F). Five of the ten largest monthly temperature departures from average occurred in 2015.

The average global land surface temperature for August 2015 was 1.14°C (2.05°F) above the 20th century average—the highest August value in the 1880–2015 record, exceeding the previous record set in 1998 by +0.13°C (+0.23°F). According to the Land and Ocean Temperature Percentiles map (shown above), much-warmer-than-average conditions was present across much of the western contiguous U.S., Mexico, South America, Africa, Europe, and parts of eastern Asia. According to the Land & Ocean Temperature Percentiles map, record warmth was observed across South America and parts of Europe, Asia, and Africa. South America, Europe, and Africa experienced their warmest August average temperature since 1910. Near- to much-cooler-than-average conditions were present across Alaska, western Canada, the central contiguous U.S., and western and southeastern Asia.

Select national information is highlighted below. (Please note that different countries report anomalies with respect to different base periods. The information provided here is based directly upon these data):

The August 2015 temperature departure for Germany was 2.8°C (5.0°F) above the 1981–2010 average—resulting in the second warmest August since 1901, according to Germany's Met Service (Deutscher Wetterdienst).
Much warmer-than-average conditions dominated across much of Argentina during August 2015, with many locations experiencing record temperatures—according to Argentina's Met Service (Servicio Meteorológico Nacional de Argentina). Some locations recorded temperatures as high as 40°C (104°F).

According to the UK Met Office, the United Kingdom experienced cooler-than-average conditions during August 2015, resulting in a national mean temperature of 14.7°C (58.5°F), which is 0.2°C (0.36°F) below the 1981–2010 average.
Spain experienced a warmer-than-average August, with an average temperature of 24.5°C (76.1°F)—which is 0.5°C (0.9°F) above the 1981–2010 average.

The average temperature for Denmark for August 2015 was 17.4°C (63.3°F), which is 1.7°C (3.1°F) above the 1961–1990 average and the warmest August since 2009, according to Denmark's Met Service (DMI).

Australia, as a whole, had a warmer-than-average August at 0.61°C (1.10°F) above the 1961–1990 average. However, Tasmania had below-average conditions, resulting in the third lowest temperature departure (-1.27°C / -2.29°F) since national records began in 1910, according to Australia's Bureau of Meteorology.

https://www.ncdc.noaa.gov/sotc/global/201508

 

don't you kind of have to know where the CO2 is at? How is it that it knows to average out? funny stuff s0n. Again, how hot is CO2? Is it the temperature of the sun when it absorbs the light energy?

 

just like i said, you're still pretending not to understand

and piling up ridiculous questions



General Overview: The Greenhouse Effect

Introduction

The "greenhouse effect" is widely discussed in the media, and although its details are complicated, its principles are not difficult to understand. Without a greenhouse effect, radiation from the Sun (mostly in the form of visible light) would travel to Earth and be changed into heat, only to be lost to space. This scenario can be sketched as follows:

Suns radiation → absorbed by Earth → Re-radiated to space as heat

The greenhouse effect is a process where energy from the sun readily penetrates into the lower atmosphere and onto the surface of Earth and is converted to heat, but then cannot freely leave the planet. This can be sketched as follows:

Suns Radiation → absorbed by Earth → some re-radiated to space as heat → some trapped by the atmosphere

Due to the presence of certain greenhouse gases that trap heat, like carbon dioxide, methane, water vapor, and CFCs, the atmosphere retains the suns radiation and warms up the planet. By increasing the abundance of these gases in the atmosphere, humankind is increasing the overall warming of the Earths surface and lower atmosphere, a process called "global warming." The figure below illustrates the radiation balance and the role of greenhouse effect.



The Radiation Balance

Illustration of the Earths radiative balance. (Adapted from: NOAA)
Another way to think about the greenhouse effect is to consider that according to physics the radiation we receive from the Sun must be equally balanced by the heat Earth radiates out to space. If we were to give back less energy than we receive, our planet would soon be too hot for life. Likewise, if we were to give back more energy that we receive, our planet would soon be too cold for life. This can be written as a balanced equation of radiation:

Solar radiation input to Earth = Earths output of re-radiated heat

If we were to measure the temperature of the Earth from space, the Earth's "surface" would show a temperature appropriate for this requirement of energy balance: a measurement of roughly -18 degrees Celsius (about 0 °F). At this temperature, our planet radiates a quantity of heat into space that is equivalent to the amount of energy received from the Sun.

At this point you may be asking how we can speak of global warming when we have just stated that the Earth (as seen from space) MUST stay at the same temperature? And how is it that the temperature of the Earths surface is only a chilly 0°F? The key to understanding this apparent contradiction is to remember that we live at the bottom of the atmosphere. As far as the radiation balance is concerned, the lower atmosphere and the surface of Earth form part of a warm interior of the planet.



Figure demonstrating the importance of greenhouse gases in regulating the temperature of the lower atmosphere. The top diagram shows a greenhouse Earth where the apparent temperature surface lies 5000m up in the atmosphere from the land surface. In the past 100 years this apparent temperature surface has been rising. By contrast, without a greenhouse effect, the Earth would look like the lower diagram.

The apparent temperature "surface" that we would see from space is located well above the real surface of the Earth where we live. This apparent temperature "surface" is about 5000 meters up (17,000 feet) within the atmosphere. To get a better handle on this concept consider the following: the difference in elevation between 0 meters and 5,000 meters corresponds to a difference in temperature of about 60°F. In other words, at sea level it is 60°F warmer than it would be without the atmosphere. For the last 100 years or so this apparent temperature surface has been moving upward in the atmosphere as a result of global warming. As the apparent "surface" rises, the bottom of the atmosphere gets warmer, a fact that can be seen in the positions of the snow line (the elevation where snow begins to form) and tree line (the elevation where it becomes to cold for trees to grow). However, despite all these changes happening in the lower atmosphere, the overall temperature of the planet as seen from space stays the same.

How is it possible that the Earth exactly balances the incoming sunlight with the outgoing heat radiation? The answer is simple: the amount of heat radiation from Earth is precisely tied to the temperature of the atmosphere. If the temperature of the apparent surface is too low and Earth radiates too little heat to keep the balance, Earth will warm up and radiate more heat into space. If the temperature of the apparent surface is too high and Earth radiates more heat than it receives, the planet will become colder and radiate less energy back to space. Overall, this negative feedback stabilizes the radiation balance despite all the variations of temperature from one place to another and within the vertical column of the atmosphere. It sets the temperature so that the incoming and outgoing energy is balanced.

Solar Variations

One last point to consider when discussing the greenhouse effect is the amount of sunlight coming in to Earth. The quantity of sunlight we receive depends on the size and the brightness of the Sun and the distance between it and the Earth. As far as we know, the size of the Sun does not change much over the time spans we are considering; we can assume it is constant. The sun's brightness varies only a little, about one-thousandth over an eleven-year sunspot cycle, but perhaps more over longer time spans. We can take that as constant too, calling the incoming energy flux "the solar constant." One of the contentious issues in the discussions about the global warming of the last 100 years that has not been fully resolved is the question of whether a brighter Sun may have contributed to the recently observed temperature rise.

http://earthguide.ucsd.edu/virtualmuseum/climatechange1/02_1.shtml

 

here one more time, jingle bells jingle bells jingle all the way, how hot is CO2? Can you answer that question? There is no build up of questions, one, one which you never answered and why I repeat it. duh!!!!!

 

like i said, it depends on the location

instead of specifying a location, all you had were more ridiculous questions

and pretenses of not understanding

 

You still haven't answered my question how hot is CO2?

 

you haven't specified a location

 

Why's that matter? You can't answer a simple question?

 

i have answered

 

you did? LOL your answer, what location. because you asked me I need to understand why that matters. And again, you can't answer, you're not really much of AGW debater I see. Oh well, there is obviously nothing of value you provide to the discussion about climate change/ global warming since you can't answer the simplest of questions concerning your religion.

Again, you haven't convinced anyone here that CO2 makes the world warmer since you can't explain how warm the gas molecule gets. see ya.

Everyone just know, this is typical discussion with a leftist agw k00k. They never have an answer on what it is they believe. Copy and paste from a program is all they ever have.

 

yes, several times and instead of responding rationally

you reacted by pretending not to understand my clear science-based answers

it matters because different locations have different temperatures

 

huh? I thought the atmosphere was the atmosphere. start with the first, troposphere:

The troposphere is the lowest portion of Earth's atmosphere. How warm is CO2 there?

Edit: BTW, I asked you if it was 85 degrees how warm would the CO2 be. So, again why does location matter? If the temperature is 85, isn't it 85?

 

that's covered on comment number 762

 

uh, no it isn't. If the surface is 85 degrees F, what is the temperature of CO2? There is no mention of CO2 temps in that post.

 

your questions are irrelevant, ridiculous and dishonest

 

Ice thickness in the Northwest Passage

 

what's your point?

other than demonstrating the cut and paste hypocrisy that you criticize others for

 

You mean posting things that are different instead of wash, rinse, repeat. You need to read more widely.