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Climate Change

Accelerated Global Warming

Hanns-Jürgen Hodann
There is now substantial evidence that three unstoppable reinforcing feedback systems that can only accelerate global warming have been triggered in the Arctic. R2 illustrates a process whereby frozen methane hydrate,  which exists in enormous quantities on the seabed of the shallow Arctic Ocean shelf, is breaking up as the ocean warms. This leads to methane gas, a greenhouse gas about 20 times more powerful than C02, bubbling up to the surface. R1 shows that as the ice cover of the ocean melts and shrinks, less sunlight is reflected back into space and more is absorbed by  the ocean, warming it as a consequence. The warmer ocean water and warmer air temperature will then melt more ice, but it will also break up more methane hydrates.   R3 describes a similar process where melting permafrost releases methane into the atmosphere, making the situation even worse. These processes are multiplicative, they reinforce each other.  Below are links to three articles that provide  evidence that this is going on now. Systems thinking tells us about reinforcing feedback loops and the associated exponential growth. Taking this and the evidence provided by the articles into account the conclusion clearly points to increasing and accelerated global warming. The recent Paris agreement on global warming may have come too late!

Global Warming Climate Change Methane Release

  • 3 years 10 months ago

Entropy and Negative Feedback may stop Growth soon

Hanns-Jürgen Hodann

Economic growth cannot go on forever, although politicians and most economist seem to think so. The activity involved in economic growth necessarily  generates entropy (disorder and environmental degradation). Entorpy in turn generates powerful negative feedback loops which will, as a response from nature, ensure that economic activity will eventually grind to a complete halt.  In these circumstances organised society cannot persist and will collapse. The negative feedback loops shown in this graph have already started to operate. The longer economic growth continues unabated, the more powerful these negative feedback loops will become. How long can economic growth continue before it is overwhelmed? It may not be very far in the future.

Economy Environment Climate Change Entorpy.

  • 9 months 3 weeks ago


Hanns-Jürgen Hodann
Capitalism is in crisis and climate change disruption is now beginning to hit the bottom line. Insurance companies know this well. According to a report by the Bank of England, insured losses have risen from $10 000 million in 1985 to $50 000 million in 2015. Climate change cannot be reversed, and extreme weather events  will undoubtedly get worse in the future strengthening the disruptive effects shown in the CLD.  Another dynamic is that companies will continue to automate and, as The Economic Policy Institute has shown, fail to reflect  productivity gains in workers' salaries. The result, stagnating salaries is disastrous for demand, given that capitalism needs endlessly rising demand and consumption. A further serious problem is that as climate change gets worse there will be increasing demands for companies to assume their responsibility and bear the costs of negative externalities.  The CLD shows these factors which are likely to lead to the collapse of the system: when capitalism can no longer generate 'capital' it has stopped to serves any useful purpose. 

Capitalism Economic Collapse Climate Change

  • 3 years 3 weeks ago


Hanns-Jürgen Hodann
The concept of 'CLOSING A FEEDBACK LOOP'  means that a loop is closed to affect the person or agents that originally are  responsible for an action so that they plainly feel its effects. This almost inevitable leads to corrective action. One of the reasons why climate change does not  arouse passion and action is that it is largely invisible and most people are not aware of it, although extreme weather events are beginning to change this somewhat. The schematic representation shows how systems thinking might help to draw attention to such situations by graphically connecting the dots to promote understand and hopefully action when people realize that there is a price to be paid for inaction.  Please note, however, that the loop does not describe dynamic behaviour in the normal system dynamics sense. 

Climate Change Systems Thinking Closing The Loop Climate Change Policies

  • 2 years 9 months ago


Hanns-Jürgen Hodann
Social movements have a major role to play in forcing politicians to act on climate change. This opinion has been clearly expressed by Pope Francis in his encyclical on climate change and, amongst others, also by Naomi Klein in her book 'This changes Everything'. The CLD suggests the need to strengthen the reinforcing loops R1 and R2 representing the activities of  environmental movements and also to disrupt the reinforcing loop R3 representing climate change  deniers. The most effective way in my opinion  to strengthen R1 and R2 is to weaken R3. This could be done by countering false arguments by pointing out on all occasions that the debate on climate change is over: climate scientists, by an overwhelming consensus, have established that anthropogenic global warming is a scientific fact. It could also be done by educating the public. The urgency of the situation suggests that the most effective way of doing this could be by closing negative feedback loops, for example, by linking extreme weather events, supported by graphic images, to global warming. Global warming can also be linked to inequality, poverty, larger forest fires,  coral reef bleaching, etc. The Pope has started the work by establishing these links in his encyclical. Of course, these are merely suggestions. Looking at the CLD carefully might well reveal other effective points of intervention

Climate Change Global Warming

  • 1 year 8 months ago

Climate-Change Movements: Influence on public opinion and government

Hanns-Jürgen Hodann
Pope Francis, in his recent encyclical on climate change, said that social movements are critical in promoting action on global warming. This simple CLD shows how the influence of climate-change movements could affect both public opinion and the government. An important aspect is that the activism of such movements will have a negative influence on the prestige of the fossil-fuel companies. This in turn will weaken their capacity to influence and to exert pressure on the government.  As the movements act, pressure on the government will increase but simultaneously the capacity of the fossil fuel industry to pressure  the government will decrease. As a result, the government will find it easier to push trough legislation to force fossil fuel companies to keep unburnable reserves in the ground. Climate change moments can contribute decisively to bring about urgently needed action on global warming

Climate Change Global Warming Fossil Fuel Companies

  • 3 years 11 months ago

Daisyworld v5b

Bob Hawkins
This Insight is a model of Daisyworld created by James Lovelock in 1982 to demonstrate the central idea behind the Gaia hypotheses that life and the environment may be considered two parts of a coupled system.

Gaia Daisyworld Climate Change

  • 4 years 10 months ago


Hanns-Jürgen Hodann

If all Americans believed that extreme weather events, droughts and wildfires are primarily caused by climate change they would soon react and demand immediate action from their political leaders. It is likely that this will happen fairly soon because of the dynamic hidden in the phrase 'Climate Change'. Wolfgang von Goethe the famous German poet and scientist said  ''we only see what we know". Cognitive psychology largely agrees and says that we only understand what we see - and give importance to it -  if we have a schema  (mental model) for what we are looking at.  As the terms 'Climate Change' become more widely used people will try to understand what they mean and start to construct schemas. As a result of this process they will soon  see  extreme weather events and wild fire in a different light as the occur again and again - after all, climate scientists told us that  their numbers and severity would  increase as a result of climate change. This simple CLD tries to illustrate this dynamic. It suggests that if you want to speed up this process, a good strategy would be to point out at every occasion possible that an increase of extreme weather events and droughts is precisely what climate scientists predicted!

Climate Change

  • 3 years 9 months ago


Hanns-Jürgen Hodann
People, generally, do not seem to be conscious of, or care about, the enormous dangers of climate change and even the possibility of a devastating war in the Korean peninsula that could turn nuclear. They carry on with their routine and banal conversations as if that was all that mattered. In the 60s there were peace demonstration, there was more awareness and public engagement in the face of the thread of nuclear war. Could the pressures and demands of modern capitalism, now no longer tamed by a competing communist system that could potentially appear to be more attractive, be a causal factor? People caught up in the turmoil of a positive feedback loop rarely perceive reality beyond it. This simple CLD tries to illustrate the dynamic and feedback loops that could be responsible for this strange apathy and how our present day economic system could be blinding us to imminent danger.

Public Awareness Climate Change Society Nuclear Confrontation

  • 3 years 1 month ago


Rolf Widmer
A very simple thermodynamic model of a planet, based on first order approximations of its (black body) radiation balance and uses two heat stores (ocean and atmosphere). It includes two radiation modulating effects i.e. albedo and green house. It is a lumped model which does not consider spatial variations and resulting mass transports - thus no heat exchange between e.g. equatorial and polar regions. As a consequence all values are surface specific i.e. per square meter. The radiation balance is in  W/m² and the heat reservoirs are in J/m² i.e. assume water and air columns with a cross section of 1 m².

Climate Change Atmosphere

  • 1 month 4 weeks ago

The dynamic that prevents confronting climate change

Hanns-Jürgen Hodann

The fact that we all strive to reduce psychologically inconsistent thoughts  is a well-researched phenomenon. When we hold two conflicting thoughts in our heads we feel an overwhelming desire to reduce this conflict. This desire can be a powerful driver in the way we behave. Most of us are aware at some level that if we took the threat of climate change seriously we would need to completely change our routines and the way we behave. Flying off on holiday would be out of the question. Swimming pools would be a past luxury. Most of us would need to give up our cars and become vegetarians. The list can be extended almost endlessly. Very often, subconsciously, we try to reduce troubling and inconvenient facts by minimizing, ignoring or even by denying them. Could this be why we hardly talk about climate change even in the face of increasingly frequent extreme weather events and obvious signs that it is occurring now?

This subject needs to be openly talked about between us and in the press. The seriousness of global warming makes it a necessity.  Only when this happens will politicians have the space and incentive to act on our behalf. But before this can happen we need to be aware of the reason why we avoid talking about this subject – this graph tries to illustrate the harmful dynamic that could be responsible for it.

Social Psychology Climate Change

  • 2 years 3 weeks ago