My belief is that climate change is likely over the coming
decades, as it always has been, and that we should prepare for it by taking measures to protect us from floods, droughts, tornadoes, hurricanes, forest fires, volcanic eruptions, tsunamis, earthquakes and prolonged heavy snow, in largely unpredictable locations. This is doubly important as the population grows and becomes concentrated in cities, which are more often than not either next to the sea or a lake or a river or an avalanche-prone mountain. International action in my view should take the form of a globally resourced service using the latest technology to rescue victims of extreme events, providing them with new, attractive habitation, schools, colleges, leisure facilities, cultural resources and places of worship. Agriculture using the latest technology (e.g.AI driven bots to assist in planting an eco-friendly variety of crops) could be linked to the new community. There are endless possibilities.
However, we need to retain humility and recognize that effects known
only to the Creator could occur. Two major climate change periods since the beginning of civilisation (i.e. over the last 10,000 years) have occurred in the last 1,000 years (The Medieval Warm Period, 950-1250 AD and the Little Ice Age, 1300-1800), long before fossil fuel power stations. The biosphere, like the brain-body system, is orders of magnitude more complex and subtle than anything we can simulate or even imagine, so there is always room for the unexpected. The types of solution exemplified above should be given priority over
too many wind turbines and solar panels, which have their own ecological costs and carbon footprints as well as causing socio-economic disruption. They have their place in particular locations (e.g. rooftops and remote areas) but the priority should be to keep the national grids secure and able to meet growing demand.
The list below is a reminder of the complexity of the problem of predicting climate change. Please contact me (John Sears) via
cosmik.jo@gmail.com
if you think it needs modifying in any way.
Human activity.
Carbon dioxide from fossil fuel burning and methane from livestock farming are playing a role in tipping the global balance towards warming rather than the cooling we would expect according to the Milankovitch cycle (see below). However, the extent to which carbon dioxide is a major cause is obscured by the observation (my understanding as a layman) that the records over geological time show that CO2 levels lag behind rather than precede mean temperature trends upward. It could be that as temperature rises due to other factors the CO2 held in sea water solution will be released, thus reinforcing the the upward trend in temperature. There is also a growing body of opinion among scientists that some of the IPCC reports are unrealistic owing to some climate change research following from a paper which, several decades ago,
unintentionally cited incomplete tree ring data. It is also true that the grid of meteorological stations covers only a small proportion of the earth's surface.
Radiant energy output
of sun. This has increased by around 25% since earth was formed, i.e.
over more than 4 billion years. (See Improbable Planet by Hugh Ross.) Remarkably, life was able to start, evolve and yield civilisation despite increases in luminosity. Very
small variations occur over decades and centuries and bear some relationship to
the number of sunspots (which is related to solar activity). The Little Ice Age included a period of low sunspot activity, with no sunspots observed over 1650-1700, when the mean temperature was lowest.
Milankovitch cycle. The
amount of sunlight reaching the earth varies according to the changing shape of
the earth’s orbit (eccentricity), the tilt of the N-S axis and the precession
of this axis. The crucial factor appears to be the amount of sunlight falling
on the northern hemisphere in any one year as a result of these factors. Milankovitch (1970s, Serbia) showed that the coming and going of ice ages
over the last 600,000 years was due to these factors. If there were no other factors we would
expect to be entering another ice age now, instead of a warm period.
Heat from below the
crust. The biosphere has more heat going into it than can be accounted for
by the sun. The difference is believed to be due to radioactive decay in the earth’s core. (See also Ocean Heat Sink below.) If this suddenly changed it could cause global warming or cooling.
Gravitational and astronomical effects. There are gravitational influences on climate which could become large in certain situations (chaos theory shows that very small events, like the fluttering of a butterfly, can potentially have dramatic effects, such as a storm on the other side of the world). The gravity exerted at the earth's surface varies very slightly with time and position due to inhomogeneities in the crust, mantle and core. Even small changes in these factors could potentially set off major changes not allowed for by present climate models. Miniscule changes in the orbit of the moon and planets would have huge effects (E.g. If a large asteroid caused a perturbation in the sun-moon system. Jupiter's motion is also crucial to the stability of Earth's orbit). There is also some evidence of effects at solar system and galactic level - this is being researched.
Atmospheric
composition. The importance of this arises from the way it affects the
absorption and reflection of radiation coming in from the sun or being
reflected back upwards from the earth’s surface. Carbon dioxide is responsible for the greenhouse effect – it acts like the glass in a greenhouse
to trap in heat. Methane is also a greenhouse gas, much more powerful than CO2
but also much less prevalent and much shorter lived. The man cause of global heating is water vapour and clouds also play a major, but uncertain role.
Plants. While alive these take in carbon dioxide
from the air, thereby cooling it through the reduced greenhouse effect. But as
they decay they give it out again, but
over a longer period. Large areas of trees affect the climate not only in this
way but also by their moistening effect on the air. The Amazon rain forest appears to have a pivatol role in determining the global climate.
Silicates, which are the main constituent of the earth's land mass, absorb CO2 when made wet by precipitation. This has been a major factor during the history of life oin earth.
Animals . The
main effect of these is due to the methane from their defecated waste and rotting carcasses. Methane
produced in this way is more of a problem than automobile greenhouse emissions
as livestock herds grow in response to the westernization of diets in China,
India etc.
Microscopic life. Bacteria
and spores living in land, sea and air sometimes
affect rainfall. E.g. spores in the ocean can be whisked up into the atmosphere
by strong winds and dispersed. Here they act as condensation nuclei for the
formation of the water drops and thence clouds. Insects can reduce the balance of combustible debris in a forest and this in turn means fewer and smaller forest fires emitting CO2.
Clouds. The type
of cloud, its thickness and its coverage affect the amount of sunlight striking the earth’s
surface and the % of radiation reflected back to its surface instead of
radiated away into space. These factors have been and still are a problem in creating
climate models.
Aerosol pollution. Particles in the atmosphere from both natural and artificial sources can have a marked effect on the cooling or warming of the atmosphere. This can either be direct, by absorbing or reflecting incoming solar energy, or indirect by altering the type and distribution of clouds. The size, shape and colour of the particles affect the way they reflect, scatter or absorb radiant energy, Major sources of aerosols include volcanoes, forest fires, aircraft and large cities. Black and brown soot from the recent forest fires, especially in the arctic regions, can cause large mainly reflective areas (e.g. snow) to absorb instead of reflect solar heat. See this NASA source and a video of forest fires in the northern hemisphere (2019).
Atmospheric
convection. Heat from the ground boils
up the air and the convection currents (i.e. wind) produced distribute warm air
over the planet and also affect the cloud type, amount and global distribution.
This in turn affects temperature, rain and snow. Hurricanes, tornadoes, gales and the jet
stream are all driven by atmospheric convection.
Ocean currents. The
bulk of the heat in the biosphere which we inhabit is stored in the ocean and
it is the global currents in the sea (e.g. the Gulf Stream) which determine the global patterns
of temperature in the air over the sea. Changes in these could dramatically affect the climate in some regions. E.g. Europe and the UK would be dramatically cooled if the Gulf Stream is stopped by sea salinity changes due to melt water from the arctic. The recent discovery of methane emissions in the Russian arctic could have a big effect on the global thermohaline circulation (Scientists Discover Record Methane Emission in the Russian Arctic - The Moscow Times).
Ocean heat sink. As the net amount of heat input to the planet from the sun and from the earth's core (the latter being due to the decay of radioactive isotopes, e.g. U and Th) changes some is absorbed by the atmosphere and some by the oceans and the relative magnitude of each type of absorption is not clear, making it difficult to predict the nature of the resultant climate change.
Methane and water vapour. As the climate warms it releases large bubbles of
methane trapped in frozen deposits under the ocean or in tundra. This causes further warming. It is 21x as powerful as carbon dioxide as a greenhouse gas and is produced by a certain kind of bacteria. It is much shorter lived than CO2, i.e. just over 10 years as opposed to over 200. Water vapour from aircraft would have a major warming influence if it accumulated in the troposphere due to increased air traffic.
Polar ice caps.
Both Arctic and Antarctic ice sheets
reflect large amounts of radiant heat from the sun back into space. Small reductions in
area cause significant increases in the amount of heat absorbed from the solar
heat reaching the earth’s surface. Similarly, the greater the ice coverage the more incident radiant heat will be
reflected.
Snow cover. As with
snow in the polar regions the snow settled on large mountain ranges like the
Himalayas and the Alps affects the percentage of solar radiation reflected or absorbed
by the earth’s surface. The recent melting of arctic ocean ice sheets is causing large volumes of moisture to accumulate in the atmosphere which could potentially come down as snow, forming thick long lasting coverings over N America and Russia in the winter. If these don't melt in the summer we could even be on track for the next Ice Age. The time scale is, as usual, uncertain but could be much shorter than previously thought - a hundred years or less, rather than thousands.
Melting glaciers. When a glacier melts it not only leads to possible flooding but reduces the area of the planet
which reflects incident sunlight away from the surface, i.e. the ground retains
incident solar energy instead of reflecting it back into space. When melt water flows into
the sea it dilutes the concentration of salt in the seawater and this has a
major effect on ocean currents which in turn affects the climate. (The more
salt the denser the water.) Warm ocean currents melting Antarctic glaciers from underneath could cause serious changes to sea level globally.
Sea ice. As with glaciers and snow, melting of sea ice (icebergs) reduces the % of sunlight reflected back into space. It also reduces the salinity and hence density of seawater, which affects ocean currents which themselves affect the distribution of heat in the oceans. However, melting icebergs make no difference to sea levels.
Volcanoes. Eruptions
from these inject huge amounts of sulphur dioxide into the air and, like carbon
dioxide and methane, this produces a greenhouse effect. The ash and dust from eruptions
also affects cloud formation and directly blots out sunlight.
Carbon dioxide absorption by weathering of rocks. About 1 billion tons per annum of atmospheric carbon dioxide is absorbed by weathering of silicate rocks. This compares to 30 billion tons emitted by civilisation. Such absorption is associated with the plate tectonic cycle which has been important in keeping air temperature constant over hundreds of millions of years.
Carbon dioxide historical perspective. The current CO2 concentration is 400 ppm, close to a historical low. It was about 760 ppm some 34 million years ago, when the Antarctic ice sheet started to take its present form (Eocene - Oligocene extinction event). It even appears to have reached 6,000 ppm around 500 million years ago. (NB If it fell much below about 150 ppm plant life could not be supported.)
Carbon dioxide absorption where ice has melted. Land and sea exposed by retreating ice is likely to be recolonized by plants and plankton which absorb carbon dioxide during photosynthesis. The surface areas involved are large and this could be a major factor in offsetting the heating effect of the reduced albedo. Conceivably it could even cause global warming to come to a halt or even reverse.
Meteor impacts. Hits by large meteors can have
global repercussions including climate change. If a large enough object hit the
earth it would of course cause a mass extinction event, like the one which
wiped out the dinosaurs 66 million years ago.
Cosmic rays. These
can also affect cloud formation , since the particles which make up
cosmic rays can cause nucleation of water drops. There does seem to be some link between them
and average temperature/rainfall.
There are already more than 65 million displaced persons worldwide and it is my belief that the only way to rescue, resettle and offer hope to these people is to set up an international rescue operation. With the technology available today and inspired leadership it should be possible to do this. This approach would, in my view, be much superior to the socio-economic disruption in both poor and rich nations throughout the world caused by seeking the kinds of carbon emission reductions being proposed by green extremists - measures not justified by the large uncertainty that carbon is the chief problem.
John Sears
author
2077: Knights of Peace
Reach me at
cosmik.jo@gmail.com
