Thoughts on the Cooling Period?

Question

I'll try and post this again and hopefully this time it will go through.

The cooling between the 1940s and 1970s is well documented. Those who agree global warming is a reality state that the cooling was an effect of an increase of atmospheric aerosols mostly though human emissions. Skeptic state otherwise and use it as 'proof' anthropogenic global warming can not occur. Lets look at various evidences then you can tell me why you think they occurred if it wasn't for an increase in atmospheric aerosol concentrations.

http://data.giss.nasa.gov/gistemp/graphs/Fig.A2.lrg.gif

As satellites only started taking reliable measurements of solar radiation in 1979 we can't really use that to show the Sun activity. However we can look at sunspots and see how active the Sun was without even needing exact measurements.

http://commons.wikimedia.org/wiki/File:Sunspot_Numbers-fr.svg

You can see from these graphs that temperatures started declining during a period of increasing solar activity. On top of that we have ground based measurements showing a decrease of 8W/m^-2 during this time period. Unfortunately I can't show the correlation between atmospheric aerosols as I can't find any historical data going back this far. However, given this data how do skeptics claim the planets cooled during this period of increased solar activity? Large volcanic eruptions usually only cool the planet for, at most, 3 years due to aerosols in the stratosphere.

http://www.leif.org/EOS/2008JD011470.pdf

Answer 1

I can't really speak for the sceptics, but I'm old enough to remember the level of atmospheric pollution in the early 1950s.



As far as I can follow their reasoning (?), sceptics argue that because some atmospheric scientists were concerned about cooling at that time, all atmospheric scientists should now be ignored when they tell us we should be concerned about warming.



Actually, the record points in the opposite direction. Even with a much less extensive database, as you point out, they were able to detect cooling, diagnose its cause, recommend remedial action (cleaner air), and, when that action was taken (albeit for other reasons, such as public health), then as predicted the cooling stopped.



If only our politicians or economists had a comparable track record of success.



Edit: I followed Richie's Royal Society link. I fully endorse his enthusiasm for the Society as an authority. I quote from its conclusions, which seem to differ from his own position:



There is strong evidence that changes in greenhouse gas concentrations due to human activity are the dominant cause of the global warming that has taken place over the last

half century. This warming trend is expected to continue as are changes in precipitation over the long term in many regions. Further and more rapid increases in sea level are

likely which will have profound implications for coastal communities and ecosystems.



58 It is not possible to determine exactly how much the Earth will warm or exactly how the climate will change in the future, but careful estimates of potential changes and associated uncertainties have been made. Scientists continue to work to narrow these areas of uncertainty. Uncertainty can work both ways, since the changes and their impacts may be either smaller or larger than those projected.



59 Like many important decisions, policy choices about climate change have to be made in the absence of perfect knowledge. Even if the remaining uncertainties were

substantially resolved, the wide variety of interests, cultures and beliefs in society would make consensus about such choices difficult to achieve. However, the potential impacts

of climate change are sufficiently serious that important decisions will need to be made.



Climate science – including the substantial body of knowledge that is already well established, and the results of future research – is the essential basis for future climate

projections and planning, and must be a vital component of public reasoning in this complex and challenging area.

Answer 2

Richy is very creative when copy-and-pasting a Royal Society study, he even manages to insert his own opinion.



The phrase "Note that the warming has again levelled off between 2000 - 2010" is no where to be found in the entire study. Quite the contrary:



Paragraph 22: "When these surface temperatures are averaged over periods of a decade, to remove some of the year-to-year variability, each decade since the 1970s has been clearly warmer (given known uncertainties) than the one immediately preceding it. The decade 2000-2009 was, globally, around 0.15oC warmer than the decade 1990-1999."



See https://answersrip.com/question/index?qid=20101202064146AAUugXB for a detailed comparison of the Royal Society quotes Richy used and the original text.

Answer 3

Interesting question, although the discussion here, which is for entertainment only, is a fair example of the "tyranny of the paradigm" a description of of those who believe in a specific idea or theory, in this case AGW, and will continue to believe that even to the point of excluding data which tends to disprove or "undemonstrate" their pet theory. Many posting here on the idea of AGW, and the theories behind it, are suffering from this malady. Treatment is available, but most paradigm believers will refuse the cure, at least those who post here.

Answer 4

I remember Dana suggested this a few years ago and frankly I laughed at it and thought he was joking. Then I realized he wasn't. Doesn't it bother you in the slightest that these convenient excuses are used to explain everything bad under the sun (except the sun). I think the theory that aerosols caused the cool period is just about as asinine a theory that I have ever heard. Why not use it to explain the Little Ice Age. Come to think of it, I think I remember Dana using it for that too, with volcanic eruptions providing the aerosols. This need to find anthropogenic explanations for every nuance in the climate stems from alarmists attempts to try to paint the climate as stable until humans came along. It is just another bit in a long list of evidence about how ignorant alarmists are about actual natural history.



Note: I didn't answer because unlike you I don't pretend to know that which is not known. Your opinion is also worthless to me.

Answer 5

Easy, the climate scientists don't explain how much aerosols were in the atmosphere to cool this off and how come it started to warm up again before aerosols were started to be regulated in the early 1980's in the United States with Europe a little behind and aerosols were not truly banned until the early 2000's World wide if my memory serves me correctly. Once again, to a trained eye, it seems like a cause and effect fallacy, we see two things that may have some correlation and one "causes" the other.

Answer 6

I'm currently at a workshop and don't have time to comment in much detail, but I wrote an article on the subject linked below. In short, there's strong evidence that anthropogenic aerosol emissions played a big role in the mid-century cooling. PDO probably played a role as well, as it switched from positive to negative phases during this period.

Answer 7

I'm currently at a workshop and don't have time to comment in much detail.

and I was looking forward to reading the book

Answer 8

Good question however there are many other times apart from 1940-1970 when CO2 output has not followed our relatively short temperature record. So lets look at the facts and actual evidence according to the Royal Society



There is very strong evidence to indicate that climate change has occurred on a wide range of different timescales from decades to many millions of years; human activity is a relatively recent addition to the list of potential causes of climate change. The shifts between glacial and interglacial periods over the past few million years are thought to have been a response to changes in the characteristics of the Earth’s orbit around the Sun. While these led to only small changes in the total energy received from the Sun, they led to significant changes in its geographical and seasonal distribution. The large changes in climate, in moving in and out of glacial periods, provide evidence of the sensitivity of climate to changes in the Earth’s energy balance, whether attributable to natural causes or to human activity.



Measurements suitable for showing how surface temperature has changed with time across the world became available around 1850. Analyses of these data, in a number of institutes, try to take into account changing distributions of measurements, changing observation techniques, and changing surroundings of observing stations (e.g. some stations become more urban with time, which can make measurements from them less representative of wider areas).



Measurements show that averaged over the globe, the surface has warmed by about 0.8C (with an uncertainty of about ±0.2oC) since 1850. The key here is that this warming has not been gradual, but has been largely concentrated in two periods, from around 1910 to around 1940 and from around 1975 to around 2000. Note that the warming has again levelled off between 2000 - 2010.



The warming periods are found in three independent temperature records over land, over sea and in ocean surface water. Even within these warming periods there has been considerable year-to-year variability. The warming has also not been geographically uniform – some regions, most markedly the high-latitude northern continents, have experienced greater warming; a few regions have experienced little warming, or even a slight cooling.



So the relationship between CO2 and the real world temperature record is far from understood and this is one reason why I and any real scientists are sceptical of AGW.



If you thumb me down your thumbing down The Royal Society a Fellowship of the world's most eminent scientists and is the oldest scientific academy in continuous existence. Their Fellows and Foreign Members, who are elected for life on the basis of scientific excellence, have included Isaac Newton, Charles Darwin, Ernest Rutherford, Albert Einstein, Dorothy Hodgkin, Francis Crick, James Watson and Stephen Hawking. Today there are approximately 1,500 Fellows and Foreign Members, including more than 70 Nobel Laureates.



Edit for Paul: Where did you actually answer the question relating to the link between CO2 and the temperature record. The royal society said what I quoted in relation to this question. It seems that you are trying to distort the YA question and answer process by quoting irrelevant information.



Gary: You also must be sceptical of AGW as you agree what I said was true about how global warming has sporadically occurred since 1850 in relation to the steady rise of CO2... I guess you cant argue with the facts?

Answer 9

Global warming is a depletion of the ozone layer, just like thinning the blanket, try it on a cold nite then you will realise that the solar temp is constant, but our blanket is thinner, cold and heat is a factor of temps, plus and minus, sunspots are occasional activities and should not be a reason tho, so are satellites, and "rubbish in space". and volcanic eruptions, etc are changes in the table, just accept it.....

Answer 10

The cooling seems to fit right in with a drop is solar activity.

Answer 11

Richie --



Everything you say is true (although incomplete) until...>>...and this is one reason why I and any real scientists are sceptical of AGW<<



The last part is simply untrue. It is not just a lie, it is a stupid lie. Why would you do that?