πŸ“š node [[climate change loops]]

Climate change is caused by the interaction of powerful reinforcing and balancing loops.

Here I describe a high level model with 8 loops.

Loop R1 A reinforcing loop. Once around the loop will reinforce an initial change. So higher temperatures increase ice melt which in turn creates more dark surfaces on earth (ocean surface area) which reduces the Albedo effect which increases temperatures! Reinforcing loops cause exponential growth or decline. They are the source of instability.

Loop B2 A balancing loop. Balancing loops aim to create stability. In this case, higher temperatures lead to evaporation which creates β€œLight clouds” (my words! The clouds that don’t rain) which accumulate into β€œHeavy clouds” (again my words) which cause precipitation which cools temperatures. Once around the loop changes the direction we started with.

Loop R3 Changes in temperature lead to human requirements for heating/cooling which is one of many factors increasing human demand for energy. This demand for energy drives fossil fuel burning which leads to more carbon in atmosphere which creates a greenhouse effect which again affects temperatures.

Loop R4 More precipitation leads to more water in the soil (ceteris paribus) driving photosynthesis and transpiration and helping to create more clouds and rainfall.

NB the amount of water held in the soil is also affected by the temperature. Higher temperatures mean more evaporation in poor quality soils. This can be ameliorated by the quality of the soil (the carbon sponge) and the land area given to it. The better the quality of the soil, the more water held in it and the less run off.

This in turn reinforces loop R1 as increased run off impacts oceans reducing the land area for animals and plants.

The poorest quality soil has no moisture. This is a desert. We can overcome desertification by ensuring high quality soils with plant cover. In the first instance we can get the cycle working by reintroducing animals (see loop R8).

Loop B5/R5 Increased photosynthesis increases carbon stored in plants and reduces carbon in the atmosphere. The detritus given off by these plants secretes carbon in the soil, improving soil quality and thus water absorption and photosynthesis. A double whammy! But only when soil quality is not being destroyed by poor agricultural management.

Over a much longer time frame the carbon in the soil is subjected to pressure from increased layers above. This creates a stable and safe earth carbon store or what we commonly call fossil fuels. Our extraction and burning of these fossil fuels releases the carbon back into the atmosphere.

Loop B6 Increasing human population increases carbon in the atmosphere via demand for energy and fossil fuels burnt plus our respiration. The long term effects on temperature create issues for human survival which in turn reduce our population.

Loop R7 Rising temperatures lead to dry conditions which allow forest and grassland fires to flourish (whether caused by humanity or storms). These fires release carbon dioxide into the atmosphere leading to higher temperatures in future. It also means there are less plants to perform photosynthesis in the short term.

Loop R8 More grazing animals means more animal detritus which improves soil quality and the proliferation of plants resulting in expansion of animal populations.

πŸ“– stoas
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