How do the laws of thermodynamics affect climate change?

Answer 1

The laws of thermodynamics tell us to expect observable changes when we perturb (change) the inputs or conditions of the environment in this case, the earth. What we put into the air, how we change the surface through logging and agriculture, and what we dump into the ocean can all wind up altering the climate if they provide a big enough change. The laws of thermodynamics tell us that factors that as changes occur in factors that influence climate, the equilibrium state will shift. What it will shift TO is still up for debate. This despite all the claims by the nay-sayers that humans have no effect on the environment and by doom-sayers that we already can predict climate change accurately enough to know what changes we must or must not make in order to assure the climate we think is optimal.

As an example: increased anthropogenic (i.e. caused by humans) CO2 can cause an increase in the greenhouse effect - or it could stimulate more plant growth - or it could cause increasing acidity of the rain - or change the pH of the ocean - OR - some combination of the above to greater or lesser degrees as well as other effects . This might mean increased melting of polar ice caps, changes in wind patterns, suppression or stimulation of growth of different organisms, increasing rainfall in some areas with decreased rain in others and, of course, changes in the average temperature in different areas.

Often the effects are difficult to predict only apparent after the fact and even then it remains open to debate. As an example - we know that the arctic ice pack seems to have shrunk significantly over the past 20 years. A large chunk of part of the Antarctic ice has has also apparently thinned - BUT - most of the Antarctic ice has thickened considerably; it seems to have thickened enough to offset the loss of ice elsewhere so that global sea levels have remained relatively constant. It represents a new equilibrium but not one that most global climate models can account for. Since the models don't reproduce that effect, they may not be reliable at predicting a tipping point where that Antarctic ice might melt like the Arctic ice and actually produce the rising sea levels we are often warned about.