Climate Change Made Easy: It's the Sun
For two decades now, 'the Great and the Good' have subjected
us, the thinking public, to a blizzard of authoritative-sounding
climate catastrophism. For instance:
- Most 20th Century warming was not, as in the past, the result
of solar influences.
- Human-caused changes to the composition of the atmosphere
now drive climate.
- Most 20th Century warming was (as will surely be the case
in the new century) caused by anthropogenic greenhouse gas emissions,
largely CO2 from burning fossil fuels.
- Global warming will harm us all---and the CO2
which causes it, is a pollutant.
British Prime Minister Tony Blair announced in Mozambique on
1 September 2002 (in support of the UN's World Summit on Sustainable
Development in Johannesburg) that "we can defeat climate
change if we want to". He meant that if we can curtail deeply
enough our use of fossil fuels, we shall stop global warming.
Of course, denying the citizens of the industrialized world the
ready availability of low-cost energy will hurt jobs and living
standards, and reduce their ability to buy goods from the impoverished
Third World---who always suffer the most when times are tough.
But this is a small price to pay for a stable climate, isn't it?
Humans can't defeat climate-change.
Continued change is inevitable; and, like it or not, the seas
will rise and fall and extreme weather events will keep coming.
Realistically, all we can do is to ensure that both human suffering
and environmental degradation are minimized.
The Sun drives climate.
This not-so-amazing fact is overlooked by the UN's Intergovernmental
Panel on Climate Change (IPCC) and its numerical modellers. They
may well accept that the Sun (in conjunction with its planetary
system) drove past climate---but then it stopped. At about
1900, the Sun retired from the climate-change game; and natural
climate 'stabilized'. Warming in the 20th Century was our
fault. But there is worse to come. If we maintain our profligate
ways, human-caused global warming of up to 5.8 ºC and sea
level rise of up to 88 cm (i.e., between 1990 and 2100) will be
the result. Frightening!
Earth has slipped into an Ice Age over the past several million
years; and the main feature of our climate---cyclic at many time-scales---is
an orbital/solar-related 100,000-year cycle of long Glacials and
short Interglacials. Only 20,000 years ago, ice was piled upon
Northern continents (1 km of ice over Detroit). Sea-level has
risen 120 metres since then---during the transition to the Holocene
Interglacial we now enjoy (warmer is better)---because warm water
expands, although primarily because the ice sheets of the Northern
Hemisphere have melted. At the human time-scale, our biggest ocean
(the Pacific) has risen about 8 cm during the past century; and
the rise appears not to be accelerating. Certainly, ice-streams
from an ever-shrinking West Antarctic Ice Sheet continue flowing
into the sea, as they have intermittently for millennia, but it
isn't enough. Accepting an imminent ten-fold increase in the rate
of sea-level rise is too big an ask.
In the Northern Hemisphere particularly, there is a (roughly)
1500-year solar-related warm/cold cycle right through the 10,000
years of the Holocene---of which the Roman Empire Warm Period,
Dark Ages, Mediaeval Warm Period and Little Ice Age are the latest
manifestations. Since the nadir of the Little Ice Age, the rebounding
warm trend has been overprinted by a 50/70 year (again solar-related)
cycle. The last cooling phase began in 1945, with renewed warming
from the Great Pacific Climate Shift of 1976/77 (which remarkable
event had an impact far beyond the Pacific). The two 20th Century
warmings totalled about 0.6 ºC, with at least half the increase
coming before WW2. In fact, much of the warming anticipated
the sky-rocketting fossil-fuel use which was supposed to have
been its cause!
Greenhouse is an atmospheric phenomenon; and IPCC got its 5.8
ºC projection by invoking a vast atmospheric CO2
increase to 2100. By assuming an almost-unimaginable rate of economic
growth in the developing world over the century ahead, and by
choosing to maximize the use of carbon-intensive coal in providing
the energy needed to drive it, IPCC attained an atmospheric CO2 concentration of 970 ppm in 2100. It then
added 30% for "uncertainties" and ran this monstrous
outcome in the most CO2-sensitive of its
seven climate models. The result: 5.8 ºC.
The underlying economic assumptions are inaccessible to the
layman, because IPCC has divided the world only into four large
economic units for the purposes of approval and publication. Hence,
down-scaling to the level of the individual countries comprising
these regions, although posted on a website, has no official standing.
However, the regional totals are official; and if one component
country were then to have its assumed future economic growth reduced,
another would have to be increased in compensation. Subject to
that caveat, per-capita GDP (expressed in thousands of 1990 US
dollars) in the USA increases from 23 to 114 between 1990 and
2100. Equivalents for Australia and South Africa are 17 to 61
and 4 to 470, respectively. I did say "an almost-unimaginable
rate of economic growth in the developing world", did I not?
That much-maligned gas, CO2, is a natural
atmospheric constituent; and many extant plant families evolved
when its concentration was 5 or more times that of today. Commercial
growers enrich the atmosphere in their greenhouses by adding CO2---to make their plants grow better; and greening
of the extra-tropical Northern Hemisphere over the 24 years of
satellite observations attests to the broader-scale benefit of
human-caused CO2 fertilization. In fact,
without endemic 'pollution' of the atmosphere by this vital plant
food, we would not be here.
Since the depths of the Little Ice Age (say 1700) and the start
of the Industrial Revolution (say 1750), atmospheric CO2
concentration has risen from 280 to 370 ppm as a result of natural
(physical and biological) and human (fuel burning and land-use
change) influences. Oceans are a far larger CO2
reservoir than the atmosphere, and the rate of atmospheric increase
jumped with the abrupt warming of the Eastern Pacific sea-surface---coinciding
with the 1976/77 Shift---to a new average of 1.5 ppm/year. Apart
from a dip after the Mt Pinatubo eruption and a spike with the
Kalimantan peat fires, little has altered during the past quarter-century:
there is no current acceleration in the rate of increase. But
in order to achieve an implausible 1260 ppm by 2100, we need not
1.5 but 9 ppm every year---starting right now. Forget IPCC's
Over the 100,000-year cycle, solar-system dynamics and continental
ice-sheet movements have dominated climate; and even the intra-decadal
El Niño/La Niña alternation looks solar-related.
Acknowledging the Sun's dominant role in climate-change would
open new lines of research---quite independent of IPCC's spurious
economics, and the numerical models which feed off them. Behavior
of the solar system may be complex, but it is certainly not chaotic.
While seeming far-fetched to some, perhaps, useful projection
of future climate may be possible after all.
|Lavoisier the Man|
Bio and Image
|Click above for latest SOHO sunspot images.|
Click here for David Archibald on solar cycles.
|Where is that pesky greenhouse signature?|
Click here for David Evans's article.