The ninth installment of a ten part series which considers the warnings of climate scientists in the context of historical revolutionary scientific theories that met strong resistance from guardians of the status quo…
by: Arthur Hoyle
Part Nine — Our Climate Future – Cassandra’s Warning
What do the climate change deniers want us to discredit and ignore? What is the consensus of thousands of climate scientists from many nations around the globe about the future of the planet whose habitat we share with many other living things?
The concept of global warming-induced climate change is relatively easy to understand. It’s basic physics. Carbon arrives on the Earth as part of the Sun’s energy. Some of it is reflected, some of it is absorbed and recycled, and some of it is stored. Carbon stored underground in fossil deposits has, for a century and a half, been burned to give us energy. Gradually, over time, this burning carbon has upset the planet’s natural radiative equilibrium, causing the atmosphere to heat in order to maintain the equilibrium. Millions of years of carbon accumulation is being released into the atmosphere, and at an accelerating rate that increases as our population, and demand for energy, increases. We are subject to these planetary forces, but not exactly in the way that astrologers of old described.
As the atmosphere warms from the release of excess carbon, the warming air affects the elements that make up climate—ocean temperature and currents, air currents, ice and snow, cloud cover, rainfall, global temperature—altering their patterns. The altering climate affects both ecosystems and their life forms, as well as human civilizations. This much is certain. What is not certain is the extent and pace of these changes, which depend on variables that can be estimated but not predicted with certainty. We know the climate is changing, and will continue to change as CO2 concentrations increase. What we do not know is how fast the climate will change because of the build-up of heat, when the change will become irreversible, and what the full consequences of the altered climate will be for life, including human life.
As the IPCC aggregated data from climate scientists around the world and issued reports, it became ever more certain that greenhouse gas emissions—primarily CO2 and methane—were heating the planet, and at an increasing rate. The panel’s qualifiers became more assertive, changing from “likely” in 2001 to “very likely” in 2007, to “extremely likely” in 2013. The growing certainty was prompted by empirical observations that were bearing out the models projections. Sea level rise, caused by the warming of the oceans, had been measured, and the acidification of the sea from the absorption of carbon, was increasing. Sea ice was shrinking, and ice sheets were melting. The global average temperature, a measure of the amount of heat in the atmosphere, was rising at rates outside the range of natural variability. In fact, these key indicators were rising more rapidly than even the most extreme IPCC projections, faster than at any time during the past 10,000 years. The IPCC projections were sounding the death knell of the fossil fuel industry, which may explain its investment in doubt.
The IPCC reports contained projections of how increases in CO2 concentrations would raise the global average temperature, and also outlined broad scenarios of anticipated impacts from a warming climate. To aid policy planners, they set targets for containing global warming below the threshold of 2° C above pre-industrial levels. They estimated that a 2° C (3.6º F) increase would accompany a doubling of CO2 concentrations from their pre-industrial level of 280 ppm. 2º C was a consensus figure. The IPCC set 2º C as a threshold beyond which climate change impacts would become seriously disruptive to human society. In 2008, the global average temperature had already risen 1º C from its pre-industrial level of 13.8º C (56.8º F). While an increase of 1º C may seem insignificant, it represents an enormous amount of global heat. Impacts from this amount of warming are already being felt across the globe: floods, severe storms, wildfires, sea level rise, melting sea ice and ice sheets.
To hold global warming to 2º C by 2050, CO2 concentrations must stabilize at 450 ppm. This requires that CO2 emissions be halved by 2050 and become close to zero by 2100. For there to be any chance of hitting this target, emissions must peak by 2020 and then begin a steady decline. But we are moving in the wrong direction. CO2 concentrations had increased to 405 ppm by the end of 2017. The rates of emissions growth were 3 ppm in 2015 and 2016, reflecting increases in emissions tonnage from global industrial activity. Developing countries like China and India with large populations continue to build coal-burning plants as sources of energy as they attempt to raise their standard of living comparable to levels already reached in the West. And western nations, fearful of slowing their economies, are reluctant to curb emissions, despite the warnings from climate scientists.
These projections represent a consensus reached among the thousands of climate scientists feeding the results of their simulation models to the IPCC. Some individual climate scientists are far more pessimistic in their outlook. James Hansen believes that CO2 concentrations should not exceed 350 ppm if melting of the Antarctic and Greenland ice sheets is to be prevented, an event that would significantly raise sea levels and reduce the Earth’s capacity to re-radiate the Sun’s energy. Evidence that these ice sheets are now in jeopardy has already been reported.
A more dire forecast comes from the independent scientist James Lovelock, the proponent of Gaia theory, which holds that the Earth functions like a single physiological system in which all parts are interconnected. Gaia is adaptive, like other living things, and has evolved to her present state over billions of years. Human life is a mere blip in her history, but has now become a threat to her health through its industrial activity and population growth. Lovelock believes the IPCC reports underestimate the climate threat because they rely on consensus, which is a political, not a scientific, process. Echoing Malthus, Lovelock sees the root problem as overpopulation. The planet cannot sustain its current human population of 7.7 billion people, projected to reach 9.7B by 2050, IPCC’s cut-off date for avoiding “dangerous anthropogenic interference” in the Earth’s climate system.
Lovelock believes we have already passed the point of no return. We can slow climate change, but we cannot stop it, nor prevent its most serious impacts. He foresees a time in the not distant future when the hot Earth will be able to support only about 100 million people, living in high and low latitudes where agriculture will still be possible. He advocates adaptation measures, which include creating safe havens—lifeboats—where the human species can survive and live in a more harmonious relationship with nature. Left to herself, Gaia will carry out the culling of the human species. Lovelock’s prognostication is pitiless, and reflects his deep anger at mankind’s abuse of its planetary home. He warns that if the extensive fossil fuel deposits buried in the Arctic are recovered and burned, as is now being considered, the result could be the death of Gaia.
The changes from the warming climate foreseen by the IPCC are less drastic, and rest on the assumption that mitigation measures, such as transition to renewable sources of energy that do not release CO2, will be carried out. But even a 2° C rise will noticeably change the climate. The IPCC outlines broad changes that will differ by geographic regions, and will occur more rapidly over land than the oceans: increased precipitation in some regions, decreases in others; increases in the number of extremely warm days and heat waves; increased frequency and intensity of floods and droughts; increased intensity of storms; sea level rise; damage to ecosystems; extinction of species. Impacts on humans will include economic losses due to extreme weather events, and dislocation of populations from regions made uninhabitable or unsustainable by changes to their ecosystems. All of these phenomena are already occurring. As the planet continues to warm they will intensify.
Climate change has been projected by the IPCC as a gradual process, but there are enough uncertainties in the factors contributing to climate change to make the possibility of abrupt and rapid climate change, occurring within years or even months, plausible. One trigger could be the thermohaline circulation, the ocean current patterns that affect climate by moving heat from the tropics to the poles. These currents become vulnerable to shutdown as the oceans warm and fresh water from melting ice flows into the sea. Another unsettling variable is the capacity of the oceans to absorb heat. As the ice sheets melt and the ocean temperature reaches a dynamic equilibrium, global heating will accelerate. No one knows the timetable for these potential tipping points.
There are several precedents for abrupt climate change bringing about the demise of civilizations. In most cases the climate event was prolonged drought that dried up food supplies and caused widespread famine and starvation. This occurred in the civilizations of Akkad and the Old Kingdom of Egypt in 2200 BC, and more recently with the Mayan civilization in AD 800. In AD 536 a mysterious catastrophic event—perhaps a series of violent volcanic eruptions—cooled the planet and caused drought and widespread disease. Should our resistance to changing our energy sources, and with them our highly consumptive way of life, bring about sudden and extreme climate change, we can expect to experience high rates of unemployment, food shortages, financial collapse, mass migrations, the spread of disease, and the outbreak of wars as nations fight for control of dwindling resources. But there are steps we can take to reduce the chances of these devastating impacts from climate change.
To Be Continued…
Arthur Hoyle is the author of The Unknown Henry Miller: A Seeker in Big Sur, published in March 2014 by Skyhorse/Arcade. He has also published essays in the Huffington Post and the zine Empty Mirror. His second non-fiction book, Mavericks, Mystics, and Misfits: Americans Against the Grain, will be published later this year through Sunbury Press.