Decadal Trends - A warming
of + 0.197
for the northern hemisphere
and a `warming' of + 0.063 °C for the southern hemisphere
From the above hemispheric temperatures, it is clear that the Northern Hemisphere shows larger swings in temperature than is the case in the Southern Hemisphere. This is due to the much larger proportion of land in the north relative to the oceans. The oceans represent about 85% of the Southern Hemisphere and thus the dominating influence on the climate there, causing a dampening of any large swings.
Note particularly the sharp, but temporary, drop in Northern Hemisphere temperature in 1992 subsequent to the eruption of Mount Pinatubo and the equally sharp temporary rise in 1998 during the big El Nino of that year. In 2002 we have also had an El Niņo, it's main impact this time being on the southern hemisphere. Such sharp swings in global temperature in response to pertubations like El Niņo indicate that `thermal inertia' - a theory often used to explain away the lack of sufficient warming suggested by the models - amounts to only a few months, not decades as claimed by the greenhouse industry.
A further problem for the greenhouse scenario here is the long-term trend in both hemispheres. Greenhouse scientists blame the lack of warming this century (compared with what the models predict) on "sulfate aerosols" from industrial emissions causing greater reflection of sunlight, thus putting a cooling brake on the predicted warming. However, if that were true, the cleaner air of the Southern Hemisphere should allow a warming to take place there, even if the Northern Hemisphere air (where most of the industrial aerosols originate) is cooled relative to the southern hemisphere due to such aerosols. Even the 1998 El Nino induced warming is more pronounced in the northern hemisphere than in the south, even though the southern hemisphere is relatively free of cooling aerosols.
The above graphs indicate differences from average temperatures of the lower troposphere of the two hemispheres. The average temperatures from which those differences are calculated do, of course, vary during the year, and they vary differently in each of the hemispheres. They also vary in such a way that the global average varies during the year. The following graph indicates those averages in kelvins (degrees Celsius plus 273.15) by day of the year.
(10 June 03)
New Scientist is a long-standing champion of `global warming', ready to believe and publish the wildest predictions of warming. Their latest effort by their long-time greenhouse writer, Fred Pearce, on 4 June 2003, is titled `Global Warming's Sooty Smokescreen Revealed'. This article promoted a `think-of-a-number-and-double-it' exercise from a climate workshop he attended in Berlin.
There, the gathered luminaries now predict, not the IPCC's upper limit of +5.8°C (itself a somewhat ridiculous figure), but have now bid it up to more than +11°C !
The excuse for taking the IPCC's upper number and doubling it is their claim that sooty haze is actually cooling the global climate, masking the warming that is really there simply waiting to come out if the haze clears.
Let's think about that for a moment. If we all do the right thing and make combustion cleaner, or even replace combustion altogether, we will get warmer still as our cooling hazy blanket disappears. What someone should have told these `scientists' at Berlin is that we already have conclusive experimental evidence that their theory is complete nonsense.
Look at the satellite temperatures of the two hemispheres here. The satellite temperatures have seen the northern hemisphere warm by +0.147° per decade since satellite temperature recording began in early 1979 (this is well below the lower limit of IPCC expectations). But the southern hemisphere has only warmed an insignificant +0.013°C over the same period (completing contradicting IPCC expectations).
Which hemisphere is the sootiest? Which has the greatest level of smoky haze?
It is the Southern Hemisphere which is the cleanest, most free of sooty haze and associated aerosols, and it is the Southern hemisphere which has seen no significant warming. The Northern Hemisphere warming may well be caused by the haze that is more prevalent there, not the other way around. If the northern hemisphere haze is cleaned up, it is cooling we can expect there, not warming.
The speculation of the Berlin `workshop' is just that - wild speculation. That New Scientist should see this as `Revelations' tells us more about New Scientist and their greenhouse policy than about any serious treatment of evidence. `Revelations' are for religions, not scientists. Maybe New Scientist can't tell the difference any more.
John L. Daly