Where is our Tipping Point?

The spring semester is about to start. I am preparing to teach a new course on Physics & Society. I was chatting about the new course with a friend – a distinguished physicist. His comment was – don’t “forget” to touch on economics. I promised to do as advised.

A few days later, I read the New York Times review of a new book titled, “The Physics of Wall Street” by James Owen Weatherall. Curious, I ordered the book. It arrived in two days and took me a weekend to finish. I found it interesting, even though I was already familiar with many of the cases that Weatherall describes.

The book discusses a number of cases in which people with a background in Physics and Mathematics did well in the financial markets. Its conclusion is that we need more of these types of people in the market, not less. This, in spite of the widely spread belief that the schemes concocted by these “quants” were partially responsible for some of the market’s painful bubble bursts recently.

I think that this would be a great book for my students to read before the course starts, mostly to familiarize them with some of the language. My objective for this course is to discuss man’s role as a part of nature, as well as explore career opportunities beyond the usual boundaries of textbooks physics, to include human activities.

The starting point in the course will be the generalized definition of Physics. One good example is the one given in the Miriam Webster Dictionary:

Physics –  science that deals with the structure of matter and the interactions between the fundamental constituents of the observable universe. Long called natural philosophy (from the greek physikos), physics is concerned with all aspects of nature, covering the behavior of objects under the action of given forces and the nature and origin of gravitational, electromagnetic, and nuclear force fields. The goal of physics is to formulate comprehensive principles that bring together and explain all discernible phenomena.

I am not an economist and I need help here. Weatherall is not an economist either, although he has advanced degrees in Physics, Mathematics and Philosophy. Climate Change should be an important part of this course (see my December 31^st blog discussing the American Physical Society’s attitude on this issue). Despite my ignorance, I have included some economic considerations in many of the posts throughout this blog, simply because I felt I had to. I will try to amplify this trend – starting with this post. Hopefully, comments from readers and students will enable me to rectify many of the misconceptions that usually come along with ignorance.

From the start (April 22, 2012), I have described the impact of climate change under a business as usual scenario, as a “self-inflicted genocide.” The reason was the IPCC finding that a reliable, computer generated, average global temperature rise of more than 4⁰C (7⁰F) will result in global climate change that will destroy around 40% of the eco systems. I have assumed that since humans are part of these ecosystems, and their destruction will result in major loss of human life, the situation fits the dictionary definition of genocide. For a short period of time, this characterization (together with Andrew Revkin’s comment on this in his blog in the New York Times) made this blog “viral” with floods of disagreements.

In the September 24 and the December 10 blogs, I showed two IPCC socio-economic scenarios that constitute the base to these predictions – the A2 and B1 scenarios. The A2 represents business as usual, while the B1 represents an example of an environmentally “friendly” scenario that stabilizes the impact to around 2.5⁰C.

There were two main differences in these scenarios: Toward the end of the century, the A2 scenario assumes a global population of 15 billion while the B1 scenario assumes that population will more or less stabilize at present levels of 7 – 8 billion. In addition, the A2 scenario assumes that fossil fuels will continue to be our main energy source at approximately the present level of 85% while the B1 scenario assumes that we replace more than 50% of our energy sources with sustainable sources that will not result in atmospheric chemical changes that impact the climate. Most of the other blogs that I wrote focused on how to achieve such a global energy transition.

I have so far omitted one important element from these discussions. The scenarios also include economic activities.

The IPCC SRES scenarios are listed here (version 1.1 – July 2000). The A2 and B1 scenarios for the global population and economic activity are listed in the table below.

MEX is the abbreviation for Market Exchange Rate.

Analyzing these data, one arrives at the astounding conclusion that the A2 scenario anticipates a 1.2% average growth in inflation-adjusted GDP/Capita from 2010 to 2050, with that growth accelerating to 1.6% from the year 2050 to 2100. It gets better with the B1 scenario, which foresees an inflation-adjusted GDP/Capita growth of 2.6% from 2010 to 2050 that decelerates to 2.2% between 2050 and 2100. At the end of the century, in the B1 scenario, an average human will live like an average American today. These averages include large developing countries with a GDP/capita 50 times smaller than that of the US. A dream come true.

These scenarios equate (at least in the case of A2) to “self-inflicted genocides,” with the survivors living like kings. That is very different from my own experience as a Holocaust survivor. One cannot escape the impression that the economic aspects of these scenarios were derived by applying a simple exponential growth equation, not taking into account anything that happens in the projected impacts on the physical environment (December 10 blog).

The most important parameter for projecting the impacts of climate change is called climate sensitivity. It projects the average global temperature rise as a function of the increased concentration of greenhouse gases in the atmosphere. The uncertainty margin in this parameter is large (see the discussion and graph in the December 10 blog) mainly because it incorporates several significant non-linear elements, which are often referred to in common lexicon as tipping points. These include the melting of long-term ice, such as glaciers and icebergs. The melting of ice on such a scale causes changes in a parameter called “Albedo,” which describes the fraction of incoming solar radiation that is being reflected back to space by the white ice surface. Melting causes changes in the reflection properties of the surface of the earth, thus changing the amount of radiation absorbed that leads to the temperature change.

Another major tipping point is the melting of the permafrost in the arctic. The permafrost captures large amounts of carbon compounds that accumulated before the ground froze. Upon melting, the carbon is released, with a significant fraction ending up in the atmosphere, adding to the concentration of the greenhouse gases there.

One of the main trapped organic compounds is methane, the main constituent of natural gas. Every molecule of methane is 20 times more active as greenhouse gas than a corresponding molecule of carbon dioxide.

Additional, important tipping points are the state of the oceans and land biota as sequesters of carbon dioxide (see the June 25 blog). Right now, for every quantity of carbon dioxide that we emit, only about half ends up in the atmosphere. The oceans are net absorbers of half of the excess while the green biota is absorbing the other half. Both land and sea store large carbon reservoirs and their ability to absorb or emit carbon dioxide depends on the ambient temperature. The tipping points take place when the atmospheric conditions force the land and sea on the planet to convert from net absorbers to net emitters. We don’t fully understand these complex physical processes but we know from basic science that they take place and have major impact on the climate.

Yet – as far as we humans are concerned, by the SRES account, we can continue to live like kings (at least those of us that survive the flooding, droughts, sinking of islands and major coastal cities, collapse of our infrastructure, major increase in extreme events, etc…). It seems to me that the only reason that this is happening is because we still treat the physical environment (including our own bodies) as a completely separate discipline from our socio-economic-cultural environment. We insist on continuing this behavior even though Climate Change no longer allows us to do so.