There is a notion that the climate of the Earth is deteriorating under the influence of generations of ‘developers’. It is asserted that the burning of fossil fuels is increasing the proportion of carbon dioxide in the atmosphere causing the air at the surface of the planet to warm. The word sustainability is hip. The generation taking up the reins of power, the best educated ever, seeks to act responsibly. In particular they see they want to curtail is the rape and pillage of scarce resources.
Concurrently with the issue of sustainability it is asserted that population growth must be contained and same sex marriage legitimized. The left has abandoned Marxism and taken on the environment. Coal is the new demon. The exploitation of animals should cease whether on the land or in the sea. This bandwagon has been especially popular in places where living standards are already high and the social security net well established. The thought is that we should be satisfied with less because ‘more now’ will mean less for succeeding generations. The waggoner’s look around and they see is other snouts in the trough. That disturbs them mightily.I see this behaviour when I feed my animals. The dog gets very agitated when the cat is fed.
But hey, before we get too excited we should ask the question ‘what temperature regime is most desirable’.
A good place to begin is with an assessment of the range of climates that the Earth currently provides.
With the advent of satellite surveillance from the late 1970s we have comprehensive data for the atmosphere across the entire globe. Prior to that time, the climate record is deficient lacking data for much of the oceans and the great bulk of the southern hemisphere. With the knowledge of relationships between atmospheric variables that are a product of the satellite age, and taking advantage of computers, it has been possible to project backwards on the basis of rather sketchy data, but only with any confidence as far as 1948. The resulting climate record was made available in 1996 as ‘reanalysis data’ and is accessible at: http://www.esrl.noaa.gov/psd/cgi-bin/data/timeseries/timeseries1.pl This data is good enough for a broad brush analysis.
Striking an average for the last 69 years we can describe the situation with respect to surface temperature. In so doing we create a snapshot of the planet.
Broadly speaking temperature varies with latitude. But by virtue of the unequal distribution of land and sea between the hemispheres the thermal regime in the northern hemisphere is very different to that in the southern hemisphere. In the mid latitudes summers are warmer and winters colder in the northern than in the southern hemisphere. The Arctic has a summer of almost five months when temperature rises above the freezing point of water. The Antarctic is frozen on a year round basis, an impossible situation so far as human habitation is concerned.
What is most comfortable? When people retire from work and are able to relocate to the places they prefer, they go to the Mediterranean, to Florida, the Bahamas and to Queensland. In the south west of Western Australia at 30° of latitude I observe that retired people hook up their caravans and migrate north in the winter. In general, people migrate to the tropics to avoid cold winters. On that basis, let’s face it quite squarely; much of the planet is on average too cold for personal comfort. People vote with their feet.
Imagine that you are a businessman, a farmer or a retired person from another planet visiting Earth to assess its suitability as a location to spend your leisure time, invest your inherited wealth or hard won superannuation. You are a warm blooded creature. You like a free-wheeling life and can see no virtue in decorating your frame with multi-coloured clothing. If the mind boggles at this prospect perhaps imagine that you are the seed of a hermaphroditic plant travelling on the wind. Where would you like to land?
Here are the choices according to latitude.
If you are a photosynthesising plant you will prefer the zone inside the red rectangle where photosynthesis at a sustaining rate is possible.If you are not wearing multi coloured clothing look for all round temperatures in excess of 25°C. If you are a cold adapted plant consider the data in the table below.
|Optimum Temperature||Cold limit for CO2 uptake|
|Agricultural C3 plants that have open stomata during the day||20-30°C||0 to -2°C|
|Deciduous trees in temperature zone||20-30°C||-3 to -1°C|
|Coniferous trees||10 -25°C||-5 to -3°C|
How do you rate the real estate?
The life forms that inhabit Earth have evolved over time. We know that species can adapt to some extent when circumstances change. When conditions become too adverse organisms migrate to seek what they need elsewhere. The Earth provides multifarious environments. However, looked at in the broad, and without the rose coloured glasses, cold weather is the Achilles heel of planet Earth, and in particular pole-wards of 30° of latitude. Cold is the circumstance that is most threatening when one is caught outdoors, even when one is endowed with the multi coloured clothing.
We are always curious as to how plants and animals can exist in the most adverse circumstances. This is because, outside the tropics, our planet is by and large, inhospitably cold in part of, or even the entire year. We feel the pinch of it.
Why then do we assume that a warming planet is a bad thing?
A QUESTION OF PRODUCTIVITY
If we look at the question simply in terms of the productivity of the Earth as dictated by surface temperature and precipitation a stark reality emerges. The map below shows net primary production (or carbon output from photosynthesis less that used in respiration). Mysteriously, many of the most productive parts are as yet sparsely populated.
One is surprised at how little of the Earth performs well in terms of plant productivity. All life forms depend upon the productivity of plants. Carbon output (as carbohydrate and cellulose) depends upon photosynthesis and is limited by temperature and precipitation. The most productive areas lie between the tropics of Capricorn and Cancer, the warmest and wettest areas on the surface of the Earth. The bulk of the rest of the Earth is by comparison a relative wasteland of, at best ‘seasonal’ productivity. Here food must be preserved, stored or transported from more productive locations to sustain a population over the period when nothing much grows. The alternative is to grow plants in a heated chamber supplemented with light and fed with compressed carbon dioxide out of thick steel walled steel cylinders at considerable expense.
In the tropics temperature ranges between 20 and 30°C across the year. Three crops are possible within the space of a year. Latitudes south of 60°south, in every month, and north of 60° north, between October and March, are uniformly inhospitable to plant life. No plant survives permanent burial in ice and snow. Between these extremes, at 30-60° of latitude the northern hemisphere winter months can be excruciatingly cold and although cold adapted plants can assimilate carbon at quite low temperatures the rate is excruciatingly slow. Snow adapted species have needle shaped leaves that hang down to inhibit the accumulation of snow so that they can remain free of that burden and access light. Trees with broad leaves drop them prior to winter choosing to hibernate rather than lose branches as they accumulate snow. In the subtropics of the southern hemisphere, although winter temperature is less limiting and there is little chance of a damaging burden of snow the area of suitable land is relatively small and much of it inhospitably dry. This is the domain of the hardy, drought tolerant, evergreen eucalypt that, when introduced to Africa and the Mediterranean, greens the dry country and displaces the local vegetation much to the chagrin of the local inhabitants who see this interloper as a weed.
A dispassionate view of the Earth, considering its ability to promote plant life, sees the planet as distinctly cooler than is desirable. Earth could support more life if it were warmer, especially in winter. Accordingly we find that the most populated parts of the globe lie in the well watered tropical and subtropical climates, mostly on the eastern side of the major continents where precipitation falls in the warmer summer months. These climates favour photosynthesis at rates that are respectable.
The basic premise that a warming planet is bad for mankind is just plain silly. The reverse is in fact the case. Modern civilization enables humans to live in relatively cool circumstances only when provided with food, elaborate and expensive shelter and energy for heating the interiors of structures. Its called ‘central heating’.Venturing outside one must don many layers of clothing, making work tedious. But it’s less tedious and precarious than working in space or on the moon. Humans do adapt very well, but there is always inconvenience and cost involved.
In locations where winters are cold animals are provided with warm shelters. They no longer forage because there is nothing to forage on. Food grown in summer is stored for the winter.
The pattern of consumption of carbohydrate by human species appears below:
It is plain that there is a mismatch between production and consumption. This reflects:
1. The ability to move commodities. In short, transportation involving machines and energy.
2. Diversity in living standards. Machines and energy are not universally available.
3. A great deal of spare capacity for further growth of population based on exploitation of potentially productive areas currently sparsely populated. Much greater numbers could be catered for if water can be made available in warm but dry locations where population density is currently very low. With machines and energy this is possible.
Given that the temperature of so much of the globe is limiting because its too cool, a little extra warmth is highly desirable. The increase in the length of the growing season associated with extra warmth, a characteristic of climate change in the northern hemisphere, has been beneficial.It should be welcomed. It should not be the cause for concern.
Given that plants use less water as the carbon dioxide content of the air increases that circumstance should be welcomed.
Relax, its all good on the climate front.
The real problem is that our societies are so poorly organized that, although energy is cheap and the capacity to produce machines has never been greater than it is at the present time there is currently a deficit in demand for machines. In many parts of the globe, including the heartlands of western civilization youth can not find useful employment. Banks are awash with funds and interest rates are at historic lows. Governments are spending a lot more than they earn without taking up the economic slack. Commodity prices are falling. No-one wants to buy.
This will end badly. Flights of fancy are counter-indicated. We must look to create the greatest good for the greatest number.