Undarleg fylgni milli kolsýrunnar og hitastigs. Hvað er að gerast...?

 

 

 

Þessi merkilega mynd er á vef prófessors Ole Humlum við Oslóarháskóla.

Á myndinni má sjá sambandið milli hitastigs lofthjúpsins og styrks CO2 síðan reglubundnar mælingar á CO2 hófust 1958.

 

Eitthvað merkilegt er að gerast.

Ferillinn ætti að vera sívaxandi frá vinstri til hægri, en það er hann alls ekki. Á síðustu árum fellur hitastigið með vaxandi styrk koldíoxíðs, CO2. Reyndar sést sama fyrirbærið einnig í byrjun ferilsins, þ.e. á árunum eftir 1958 þegar styrkur CO2 var miklu lægri en í dag.

 

Hvað segir Prófessor Ole Humlum um þetta fyrirbæri? Sjá neðst á síðunni hér.

 

Diagram showing HadCRUT3 monthly global surface temperature estimate plotted against the monthly atmospheric CO2 content according to the Mauna Loa Observatory, Hawaii, back to March 1958. The red line is a polynomial fit with key statistics listed in the upper left part of the diagram.  Last month incorporated in the analysis: October 2010 (inside red circle). Last diagram update: 22 December 2010.

 

The diagram above shows all HadCRUT3 monthly temperatures plotted against the monthly Mauna Loa CO2 values, since the initiation of these measurements in 1958. As the amount of atmospheric CO2 have risen steadily since 1958, although with annual variations, the oldest values of temperature and CO2 are plotted close to the left side of the diagram, and more recent values are progressively plotted towards the right side of the diagram. 

By this, the diagram illustrates that the overall relation between atmospheric CO2 and global temperature apparently has changed several times since 1958.

In the early part of the period, with CO2 concentrations close to 315 ppm, an increase of CO2 was associated with decreasing global air temperatures. When the CO2 concentration around 1975 reached 325 ppm this association changed, and increasing atmospheric CO2 was now associated with rising global temperatures. However, when the CO2 concentration at the turn of the century reached about 378 ppm, the association changed back to that characterizing the period before 1975. Thus, since 2000, increasing concentration of atmospheric CO2 has again been associated with decreasing global temperature.

The diagram above thereby demonstrates that CO2 can not have been the dominant control on global temperatures since 1958. Had CO2 been the dominant control, periods of decreasing temperature (longer than 2-5 years) with increasing CO2 values should not occur. It might be argued (IPCC 2007) that the CO2 dominance first emerged around 1975, but if so, the recent breakdown of the association around 2000 should not occur, either.

Consequently, the complex nature of the relation between global temperature and atmospheric CO2 since at least 1958 therefore represents an example of empirical falsification of the hypothesis ascribing dominance on the global temperature by the amount of atmospheric CO2. Clearly, the potential influence of CO2 must be subordinate to one or several other phenomena influencing global temperature. Presumably, it is more correct to characterize CO2 as a contributing factor for global temperature changes, rather than a dominant factor.

The breakdown of the positive temperature-CO2 relation since about 2000 (diagram above) have now lasted 10-11 years. This suggests that the recent global temperature development might deviate significantly from previous short-lived (2-5 years) periods of cooling derived from oceanic and volcanic activity as seen several times between 1975 and 2000. There are two possibilities: 1) Global air temperatures may again begin to increase in a short while. 2) The recent development may represent the beginning of a more thorough and long-lasting cooling, perhaps similar to the cooling period after 1940. As usual, time will show what is correct.

 

Ekki vil ég reyna að bæta nokkru við þessi orð prófessorsins og ekki er við bloggarann að eiga ef einhverjum mislíkar hegðun náttúrunnar eða skrif Dr. Ole Humlum.

Hitamæligögn eru frá hinni virtu stofnun Climate Research Unit. CO2 gögn eru frá NOAA.

 

Sjá nánar síðuna Climate Reflections sem er einn kafli vefsíðunnar Climate4You.com
Á vef prófessors Ole Humlum er fjölmargt fróðlegt. M.a. er myndin sem er hér fyrir neðan þaðan.

 

 Smella má tvisvar á myndir til að stækka

 

 

Um prófessor Ole Humlum

Smella hér til að sjá greinasafn prófessorsins

 

 

 

"Margt er skrýtið í kýrhausnum"