This post is directed at the ABC News (Aus), ‘Drum Opinion’ post of the same name! Ref: http://www.abc.net.au/unleashed/2761976.html
The foregoing comments in previous parts apply to funding and other influences. It is also appropriate to iterate that addressing one side of an issue is not “clearing up the debate “, which is why this blog is attempting to address the “other side”.
- Part Four: Our effect on the earth is real: how we’re geo-engineering the planet (reference: ‘The Conversation’ website)
“CLEARING UP THE CLIMATE DEBATE: Director of the Melbourne Energy Institute and Professor of Geology Mike Sandiford explores the staggering ways we influence the shape of the globe.”
Mike presents a comprehensive article relating heating energy warming of our planet to CO2 forcing – e.g.,
The radiative forcing of a doubling of CO₂ is about 1300 trillion watts – or 28 times the energy released by plate tectonics.
And we are well on the way to doubling CO₂. In the past hundred years we have added almost 40%, and warming that can only plausibly be attributed to a greenhouse effect is not only heating the atmosphere, but is also pumping heat into the oceans and the crust at a phenomenal rate.
And here am I faithfully espousing other theories about CO2 being the quantity of a trace element (0.04%) and a minor green house gas component. If I can’t come up with a reasonable backing for the “deniers” I am in deep trouble. Of course, I can only rely on other’s expertise and knowledge.
CO2 Science, presents another scenario, Firstly this video:
Carbon Dioxide and Earth’s Future, Persuing the Prudent Path. by Craig D. Idso and Sherwood B. Idso, Center for the Study of Carbon Dioxide and Global Change
Reference p6: Graph available on the website above.
With respect to air temperature, the climate-alarmist contention is multifaceted. It is claimed that over the past several decades: (a) earth’s temperature has risen to a level that is unprecedented over the past millennium or more, (b) the world has been warming at a rate that is equally unprecedented, and (c) both of these dubious achievements have been made possible by the similarly unprecedented magnitude of anthropogenic CO2 emissions, due to humanity’s ever-increasing burning of fossil fuels such as coal, gas and oil.
With respect to the level of warmth the earth has recently attained, it is important to see how it compares with prior temperatures experienced by the planet, in order to determine the degree of “unprecedentedness” of its current warmth.
Taking a rather lengthy view of the subject, Petit et al. (1999) found that peak temperatures experienced during the current interglacial, or Holocene, have been the coldest of the last five interglacials, with the four interglacials that preceded the Holocene being, on average, more than 2°C warmer (see figure at right). And in a more recent analysis of the subject, Sime et al. (2009) suggested that the “maximum interglacial temperatures over the past 340,000 years were between 6.0°C and 10.0°C above present-day values.” If anything, therefore, these findings suggest that temperatures of the Holocene, or current interglacial, were indeed unusual, but not unusually warm. Quite to the contrary, they have been unusually cool..
But could the higher temperatures of the past four interglacials have been caused by higher CO2 concentrations due to some non-human influence? Absolutely not, for atmospheric CO2 concentrations during all four prior interglacials never rose above approximately 290 ppm; whereas the air’s CO2 concentration today stands at nearly 390 ppm.
Combining these two observations, we have a situation where, compared with the mean conditions of the preceding four interglacials, there is currently 100 ppm more CO2 in the air than there was then, and it is currently more than 2°C colder than it was then, which adds up to one huge discrepancy for the world’s climate alarmists and their claim that high atmospheric CO2 concentrations lead to high temperatures. The situation is unprecedented, all right, but not in the way the public is being led to believe.
This website presents volumes of relevant information, completely contradicting the Mike Sandiford article.
Looking for more:
Another seemingly valid point of view is presented here:
Including an impressive list of qualified persons (over 31,000) signing a petition to support CO2 being a minor factor.
So there is plenty of conflicting information providing good support for both sides. Could Mike possibly be wrong?
The following information from ‘Climate4You’ provides a scenario which might explain why Mike hasn’t got it quite right.
Diagram showing the GISS monthly global surface air temperature estimate (blue) and the monthly atmospheric CO2 content (red) according to the Mauna Loa Observatory, Hawaii. The Mauna Loa data series begins in March 1958, and 1958 has therefore been chosen as starting year for the diagram. Reconstructions of past atmospheric CO2 concentrations (before 1958) are not incorporated in this diagram, as such past CO2 values are derived by other means (ice cores, stomata, or older measurements using different methodology), and therefore are not directly comparable with modern atmospheric measurements. The dotted grey line indicates the approximate linear temperature trend, and the boxes in the lower part of the diagram indicate the relation between atmospheric CO2 and global surface air temperature, negative or positive. Last month shown: May 2011 (CO2) and May 2011 (GISS). Last diagram update: 19 June 2011.
Most climate models assume the greenhouse gas carbon dioxide CO2 to influence significantly upon global temperature. It is therefore relevant to compare different temperature records with measurements of atmospheric CO2, as shown in the diagrams above. Any comparison, however, should not be made on a monthly or annual basis, but for a longer time period, as other effects (oceanographic, etc.) may well override the potential influence of CO2 on short time scales such as just a few years. It is of cause equally inappropriate to present new meteorological record values, whether daily, monthly or annual, as support for the hypothesis ascribing high importance of atmospheric CO2 for global temperatures. Any such short-period meteorological record value may well be the result of other phenomena.
What exactly defines the critical length of a relevant time period to consider for evaluating the alleged importance of CO2 remains elusive, and is still a topic for debate. The critical period length must, however, be inversely proportional to the temperature sensitivity of CO2, including feedback effects, such as assumed by most standard climate models.
After about 10 years of global temperature increase, IPCC was established in 1988. Presumably, several scientists interested in climate then felt intuitively that their empirical and theoretical understanding of climate dynamics was sufficient to conclude about the importance of CO2 for global temperature. However, for obtaining public and political support for the CO2-hyphotesis the 10 year warming period leading up to 1988 in all likelihood was important. Had the global temperature instead been decreasing, public support for the hypothesis would have been difficult to obtain. Adopting this approach as to critical time length, the varying relation (positive or negative) between global temperature and atmospheric CO2 has been indicated in the lower panels of the diagrams above.
Click here to read a few reflections on the relation between global temperature and the amount of atmospheric CO2.
So the next question is – is Mike’s assessment of the forcing ‘factor’ an agreed figure?
Then, there is a need to verify the original ‘historic’ CO2/ global temperature relationship as current and valid. Arthur Woodward as a reference is slightly in question, firstly science then was a far cry from current knowledge, secondly (below the belt), “Woodward’s reputation suffered from his involvement in the Piltdown Man hoax”.
For the sake of this exercise, there is enough doubt regarding the CO2 forcing for it not to be taken for granted.
Post publish revision – an important addition:
But the issue is not whether carbon dioxide warms the planet, but how much.
Most scientists, on both sides, also agree on how much a given increase in the level of carbon dioxide raises the planet’s temperature, if just the extra carbon dioxide is considered. These calculations come from laboratory experiments; the basic physics have been well known for a century.
The disagreement comes about what happens next.
The planet reacts to that extra carbon dioxide, which changes everything. Most critically, the extra warmth causes more water to evaporate from the oceans. But does the water hang around and increase the height of moist air in the atmosphere, or does it simply create more clouds and rain? Back in 1980, when the carbon dioxide theory started, no one knew. The alarmists guessed that it would increase the height of moist air around the planet, which would warm the planet even further, because the moist air is also a greenhouse gas. [emphasis mine]
But it didn’t increase the height of the moist air around the planet as subsequent studies have shown since that time. However, that theory or premise became the heart of the modeling that was done by the alarmist crowd.”
(The whole article is covered in my post Former “alarmist” scientist says Anthropogenic Global Warming (AGW) based in false science
[Iterating: By all means control pollution if it provides cleaner air for man, animals and all biological welfare. But forget about CO2 being a pollutant. It is likely that BP’s Mexican Gulf pollution, the current increased volcanic emissions, together with Japan’s TEPCO’s ionising radiation are, by orders of magnitude, a greater concern than CO2.
Carbon trading has yet to be proved necessary and the motivation has yet to be made clear to the public.
This post is obviously not a complete, scientific treatise on the subject. It is however, a guide to the reader to indicate that the ‘warmist’ papers are not to be taken at face value. They need to be analysed and proven to be above question before acceptance, because they are agenda-driven and might cost you your lifestyle and maybe even your freedom.]
The other series articles will be addressed, in turn.
Comments on “open letter” are Part 1: “Conversations: Climate change is happening” Part 1.
Comments on “greenhouse effect” are Part 2: “Conversations: Climate change is happening” Part 2.
Comments on “alarmist AGW views justified” are Part 3: “Conversations: Climate change is happening” Part 3.
Climate change: Why is it a hot topic? (donovanhand.wordpress.com)