What causes climate change and how will it effect global environmental and economic systems?

By David Holland,
Grad. Dip. Environmental Management, B.A.S Env. Planning.
This article has been derived from research related to studies in the subject climate change impacts, mitigations and adaptation compiled by Professor Andrew Rawson as part of a Master of Environmental Management at CSU. 

This blog is about a scenario of a briefing note to a minister on anthropogenic climate change.

This briefing note is to a government official somewhere in the world whom is somewhat convinced of the existent of climate change and recognises that climates do change over thousands and even millions of years, but is unsure of the fact that the effects of climate change are actually caused by man-made processes and that the burning of fossil fuels has made any difference to something as fundamental as the climate. He is unconvinced that a few degrees will make any large difference to the climate in the long or short term and such changes, he would suggest, would have little effect of the national or world economies. (A. Rawson 2016)

This note below is an attempt to convince a government politician of the need for urgent action to reduce the causes of anthropogenic climate change. Climate change that will occur in the near future that will affect global natural and economic systems.

A fictitious briefing notes to a Minister on anthropogenic climate change

 From the start of the industrial revolution in the 1880’s, the world has used fossil fuel energy to power an ever increasing amount of applications for industry and the home through coal powered electricity generation and fossil fuel powered transport. The invention of the steam engine and then the coal fired steam turbine has been at the forefront of the transformation. In the early 1900’s Road transport changed from bullocks to truck and buggies to cars, both powered by the application of burning fossil fuels in the form of petrol and diesel.

Staggering amounts of oil based fuels are used every day. Coal is still used in very high quantities to power all our homes and workplaces even though many countries have small plants of more sustainable fuels to generate power. The use of this type of fuel has a cost and that cost is the by-product of the burning process which is carbon dioxide (CO2).

In pre-industrial times humanity burnt wood and then trees were replaced by natural processes or planted giving the opportunity for more wood fuels to be burnt and the cycle did not add a considerable amount of CO2 to the atmosphere, but over the last 150 years mankind has been mining fossil deposits at an ever increasing rate and burning this to produce energy. These fossil deposits are materials laid down over millions of years. These materials contain carbon that has not seen the light of day for millions of years and now millions of tons of this material is burnt and produces tons of CO2, liberating it to the global atmosphere.

As a result, the carbon cycle from plants to the atmosphere is now out of balance. This means that there is a CO2 positive contribution to our atmosphere.

But out of that positive contribution 93% of the CO2 is able to be absorbed by the ocean and other carbon sinks. So where is the problem?

The problem is that the CO2 and other greenhouse gases (GHGs) such as methane and nitric oxide create a warming effect in the atmosphere. This warming is created by the suns radiation being converted to heat energy when it hits the land and the heat being trapped in the atmosphere by these GHGs.

As the concentrations of these gases increase over time more heat is retained and the average global temperature increases in the atmosphere. This increase is set to change global climate.

That means that although we will still have cooler days and warmer days, overall combined the temperature will be warmer.

Increased global temperatures will also have a flow on effect where warmer atmospheres will make the oceans warmer. Warmer oceans will affect a range of weather patterns over time through changes both to evaporation patterns and the potential for oceanic currents to change. 

 Monsoon rains will move from the tropics to the temperate zones. There will be more precipitation along the coastal regions and less in the interior. There will be bigger storms creating more damage to life and property.

With warmer atmospheres and warmer oceans there will be more glacial retreat and more melting of the sea ice in the polar regions. This will affect the food supply, breeding habits and habitat of many cold region animals.

Agriculture will be affected in the inland due to less rainfall. Coastal regions will have higher storm surge events creating flooding.

With the warming of the oceans, the melting of polar ice and the melting of mountain ice caps there will be more water in the oceans and with higher temperatures there will be an expansion of the sea water, both contributing to an overall sea level rise along our coastlines.

This sea level rise increases the risk of storm flooding and will affect not only private property but sensitive eco-systems in salt marshes and freshwater wetlands. It will affect low lying agricultural land and the net result will be higher insurance premiums.

It is true that the climate has changed over the period of the earth’s existence, but present changes are much more rapid than the earth has ever seem.

 Although there have been many extinctions over the years, because of this rapid change many more organisms will be at risk simply because they will not have the capacity to move in the face of this rapid change. In past global warmings and coolings extended over thousands of years. Animal species and their food sources had time to migrate to suitable climates. But this climate change event is different and ecological systems will be severely affected.

Coral’s symbionts are sensitive to warmer water and on many occasions over the last few years coral bleaching has occurred were these symbionts have been killed off.

Polar bears are reducing in numbers due to the sea ice retreating and now in 2016 very little remains in many areas of the habitat of the polar bear.

There have been paleoclimate changes in the past. Ice ages and interglacial periods have often been driven by changes in the earth’s orbit. And as far as can be determined the earth is now in an orbital pattern that should be providing cooler climate conditions, but in opposition to this pattern the earth is heating up. (according to recorded data over the last hundred years and from ice core data going back in time over 400,000 years)

By assessing the ice core data and correlating the atmospheric temperatures when the ice was laid down and measuring the concentrations of CO2 found in tiny air bubbles in the samples, scientist can make a correlation of the temperature and the CO2 concentrations over that 400,000 year period.

Their data analysis concludes that long term temperature trends are affected by CO2 concentrations in the atmosphere.

But there is a large amount of CO2 mixing with the ocean waters and this is tending to acidify the oceans ever so slightly. This, over time, may have an effect on a range of marine animals not least shell accreting molluscs which may find it harder to build shells in acidic conditions.

Warming seas causing more coastal precipitation could produce fresher waters in coastal regions and saltier waters in mid oceans, potentially altering subduction patterns, which in turn could alter sensitive and important ocean currents.

Changes to these currents, in particular currents that bring nutrients from the ocean floors could affect food chains for fisheries in some regions.

It is not just about the atmosphere warming it is about changes to a range of ecological system that will affect human habitation and our life style long term.

 If we were to consider the precautionary principal, we should reduce our emissions of CO2 immediately. But it is evident that the volume of new CO2 that has been poured into the environment over the last 150 years is massive and it has to have gone somewhere.

The volumes of methane (one of the GHGs) from agriculture that goes into the air from farm practices and animal husbandry is massive let alone what emanates from land fill.

The amounts of nitrates (that produce nitric oxide another GHG) that come from agricultural fertilisers and from other source is huge and all contribute to not only global warming but a range of other effects as well.

Can the planet cope with the CO2 humanity is producing? The answer is yes it can for a period, but when the oceans become effectively saturated with the gas CO2 and conditions for the growth of phytoplankton at the bottom of the food chain in the oceans becomes too toxic for them and they die, the oceans will become hypoxic and will no longer be able to absorb the CO2. In fact, the oceans will tend to produce CO2 putting it back into the atmosphere. By then large amounts of the oceans will be unable to sustain habitats for many marine creatures.

 It is evident that man-made CO2 emissions is not just about global warming and a shift of warmer climates towards the poles, it is about fundamental changes to the way ocean currents run which effect global weather patterns. It is about fundamental and deep changes to ecologies and the very survival of mankind in the medium and long term or at least how humanity lives and what resources will be available to help create any kind of stable economy into the future.




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