By John Scales Avery*
The central problem which the world faces in its attempts to avoid catastrophic climate change is a contrast of time scales. In order to save human civilization and the biosphere from the most catastrophic effects of climate change we need to act immediately. Fossil fuels must be left in the ground. Forests must be saved from destruction by beef or palm oil production.
These vitally necessary actions are opposed by powerful economic interests, by powerful fossil fuel corporations desperate to monetize their underground “assets”, and by corrupt politicians receiving money from the beef or palm oil industries.
However, although some disastrous effects of climate change are already visible, the worst of these calamities lie in the distant future. Therefore it is difficult to mobilize the political will for quick action. We need to act immediately, because of the danger of passing tipping points beyond which climate change will become irreversible despite human efforts to control it.
Tipping points are associated with feedback loops, such as the albedo effect and the methane hydrate feedback loop. The albedo effect is important in connection with whether the sunlight falling on polar seas is reflected or absorbed. While ice remains, most of the sunlight is reflected, but as areas of sea surface become ice-free, more sunlight is absorbed, leading to rising temperatures and further melting of sea ice, and so on, in a loop.
The methane hydrate feedback loop involves vast quantities of the powerful greenhouse gas methane, frozen in a crystalline form surrounded by water molecules. 10,000 gigatons of methane hydrates are at present locked in Arctic tundra or the continental shelves of the world’s oceans. Although oceans warm very slowly because of thermal inertia, the long-term dangers from the initiation of a methane-hydrate feedback loop are very great. There is a danger that a very large-scale anthropogenic extinction event could be initiated unless immediate steps are taken to drastically reduce the release of greenhouse cases.
The World Is on Fire!
“The world is on fire!” says Swedish climate activist Greta Thunberg. She is right. California is burning. The Amazon is burning. Indonesia is burning. Alaska is burning. Siberia is burning. These fires have been produced partly by the degree of climate warming that has already occurred, and partly by human greed for profits, for example from beef production or palm oil.
New research has shown that rising sea levels could wipe out many major cities by 2050.
Speaking at the opening ceremony of the UN climate conference COP24, the universally loved and respected naturalist, Sir David Attenborough, said:
“If we don’t take action, the collapse of our civilizations and the extinction of much of the natural world are on the horizon.”
Sir David’s two-part program, “Climate Change: The Facts” is currently being broadcast by BBC Earth. Hopefully, this important documentary film, like Leonardo DiCaprio’s excellent film “Before the Flood”, can do much to mobilize public opinion behind the immediate action that is needed to save the long-term future of human civilization and the biosphere.
Recently more than 7 million young people in 150 countries took part in strikes aimed at focusing public opinion on the need for rapid climate action. The Extinction Rebellion movement, which started in the UK, has now spread to many countries, and is also doing important work. In the United States, popular political figures such as Bernie Sanders and Alexandria Ocasio-Cortez are doing much to mobilize public opinion behind the Green New Deal and much to counteract Donald Trump’s climate change denial.
The Remarkable Properties of Exponential Growth
Positive feedback loops occur when the presence of something leads to the generation of more of the same thing. For example in the presence of an unlimited food supply, the growth of a population will lead to more individuals reaching reproductive age, and hence an accelerated growth of the population. This type of relationship leads to the mathematical relationship known as exponential growth.
Exponential growth of any quantity with time has some remarkable characteristics, which we ought to try to understand better, since this understanding will help us to predict the future. The knowledge will also show us the tasks which history has given to our generation. We must perform these tasks with urgency in order to create a future in which our descendants will be able to survive.
If any quantity, for example population, industrial production or indebtedness, is growing at the rate of 3% per year, it will double in 23.1 years; if it is growing at the rate of 4$\%$ per year, the doubling time is 17.3 years. For a 5% growth rate, the doubling time is 13.9 years, if the growth rate is 7% (the rate of economic growth that China’s leaders hope to maintain), the doubling time is only 9.9 years. If you want to find out the doubling time for any exponentially growing quantity, just divide 69.3 years by the growth rate in percent.
Looking at the long-term future, we can calculate that any quantity increasing at the modest rate of 3% per year will grow by a factor of 20.1 in a century. This implies that in four centuries, whatever is growing at 3% will have increased by a factor of 163,000. These facts make it completely clear that long-continued economic growth on a finite planet is a logical absurdity. Yet economists and governments have an almost religious belief in perpetual economic growth. They can only maintain this belief by refusing to look more than a short distance into the future.
Exponential decay of any quantity follows similar but inverse rules. For example, if the chance of a thermonuclear war will be initiated by accident or miscalculation or malice is 3% in any given year, the chance that the human race will survive for more than four centuries under these conditions is only1 in 163,000, i.e. 0.000625 percent. Clearly, in the long run, if we do not completely rid ourselves of nuclear weapons, our species will have no hope of survival.
Besides nuclear war, the other great threat to the survival of the human species and the biosphere is catastrophic climate change. The transition to 100% renewable energy must take place within about a century because fossil fuels will become too rare and expensive to burn. But scientists warn that if the transition does not happen much faster than that, there is a danger that we may reach a tipping point beyond which feedback loops, such as the albedo effect and the methane hydrate feedback loop, could take over and produce an out-of-control and fatal increase in global temperature.
In 2012, the World Bank issued a report warning that without quick action to curb CO2 emissions, global warming is likely to reach 4 degrees C during the 21st century. This is dangerously close to the temperature which initiated the Permian-Triassic extinction event: 6 degrees C above normal. During the Permian-Triassic extinction event, this occurred 252 million years ago. In this event, 96 percent of all marine species were wiped out, as well as 70 percent of all terrestrial vertebrates.
Is a quick transition to 100% renewable energy technically possible? The technology is available, remarkable characteristics of exponential growth can give us hope that it can indeed be done, provided that we make the necessary effort. Governments currently give enormous subsidies to fossil fuel industries. These must be stopped, or better yet, shifted to subsidize renewable energy. If this is done, economic forces alone will drive the shift to renewable energy. The remarkable properties of exponential growth can give us hope that the transition will take place rapidly enough to save the future of our planet from the worst effects of climate change.
Feedback Loops and Ethics
All of the major religions of the world contain some version of the Golden Rule,
“Do unto others as you would have them do unto you”.
In Christianity, there is a striking passage from the Sermon on the Mount:
“Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy. But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you.”
This seemingly impractical advice, that we should love our enemies and do good to them, is in fact extremely practical. It prevents the feedback loops of revenge and counter-revenge that we see so often in today’s conflicts. In fact, if nations that claim to be Christian really followed this commandment, their participation in war would be impossible. Conflicts can be prevented by unilateral acts of kindness.
Feedback Loops and the Information Explosion
In 1965, the computer scientist Gordon E. Moore predicted that the number of components per integrated circuit would increase exponentially for the next ten years. In 1975, he revised his growth rate to correspond to a doubling time of every two years. Astonishingly, Moore’s Law, as this relationship has come to be called, has proved to be valid for much longer than he or anyone else believed would be possible.
Moore’s Law is an example of the fact that the growth of knowledge feeds on itself. The number of scientific papers published each year is also increasing exponentially. This would be all to the good, if our social and political institutions matched our technology, but because of institutional and cultural inertia, the exponentially accelerating rate of technical innovation is threatening to shake human society to pieces. We need new global institutions of governance and new global ethics to match our new technology.
*About the author: John Scales Avery, Ph.D., who was part of a group that shared the 1995 Nobel Peace Prize for their work in organizing the Pugwash Conferences on Science and World Affairs, is a member of the TRANSCEND Network and Associate Professor Emeritus at the H.C. Ørsted Institute, University of Copenhagen, Denmark. He is chairman of both the Danish National Pugwash Group and the Danish Peace Academy and received his training in theoretical physics and theoretical chemistry at M.I.T., the University of Chicago and the University of London. He is the author of numerous books and articles both on scientific topics and on broader social questions. His most recent books are Information Theory and Evolution and Civilization’s Crisis in the 21st Century (pdf).