Politics cloud the issue of climate change. We have a global economy driven by fossil fuels. Whoever controls the energy controls the power. Some have it and want to keep it. Others lack it but want to grab it.
The first political argument often cited is a flat out denial that our climate is warming. However, the scientific evidence is very clear. There are over a thousand years worth of data in tree rings, sediment cores, ice cores, corals, and historical records. The retreat of glaciers and polar ice during the 20th Century has been quantified, and in the case of glaciers, is visible to the naked eye. Along with lab experiments and 160 years of temperature records, the case for warming is undeniable.
A second political argument recognizes a changing climate, but does not ascribe that change to human causes. The evidence used to deny human implication in climate change is the shifts between 17 major ice ages and warming periods that occurred during the Pleistocene.
In light of that, we discuss natural triggers for changing climate.
Climate can be altered by short and long-term changes in the atmosphere, like volcanoes, global fires releasing greenhouse gasses, or the asteroid that ended the Cretaceous. Every three to seven years there are linked changes in the atmosphere and ocean that cause El Niño events. Every decade or so there is a sunspot cycle and every 75 years or so, there is an effect that modulates those sunspot cycles. The latter can change climate for several hundred years in parts of the earth (but not all of the earth). An example could be the Little Ice Age of Europe between the years 1100 and 1300. Variations in the Earth’s orbit around the sun likely caused the recent ice ages of the Pleistocene. Most of these methods increase or decrease energy from the sun to force climate change.
In our present situation, we see temperature increases in the lower level of the atmosphere and cooling in the outer atmosphere. We also see night temperatures proportionately rising more than day temperatures, winter temperatures rising more rapidly than summer temperatures, and a greater increase in temperatures at high latitudes than at the equator. All of those effects are the opposite of what you would expect if our warming was caused by an increase in energy from the sun.
On the other hand, global CO2 records are the highest they have been in 800,000 years of records taken from ice cores. During these years, CO2 varied between 180 and 190 parts per million (ppm) during global cooling periods and between 270 and 290 ppm during the warm periods. As of June 2012, we are at 395.7 ppm. The CO2 numbers have increased steadily since the Industrial Revolution.
Another greenhouse gas associated with human activities is methane. Methane gas has 20 times the heating trapping ability as CO2. The biggest human source of methane is livestock production. However, melting perma frost is also releasing methane that has been locked up frozen for thousands of years. Methane is at the highest level of the last 800,000 years.
Greenhouse gasses hold the heat, and that accounts for the lower level of the atmosphere being warmer than the outer level of atmosphere, night temperatures rising over day temperatures, winter temperatures rising more than summer temperatures, and polar temperatures rising more than equatorial temperatures.
The consequences of climate change on rising sea levels, acidification in the ocean, increasing desertification, and the loss of fresh water have been amply discussed. Much of the time, these effects are discussed as if climate change moves in a steady, linear fashion. Most of nature, however, reacts in a non-linear fashion, largely because of positive feedback. For example, higher global temperatures mean that more tundra permafrost melts, which releases more CO2 and methane.
In turn, those higher greenhouse gas levels further increase temperatures, and that melts even more permafrost. Or, rising temperatures melt ice. Because ice reflects heat whereas darker surfaces, like blue water, hold heat, melting ice raises temperatures and that melts more ice. The key is that not only do temperatures rise, they do so at an accelerating, or non-linear rate. This has been quantified in measuring loss of glaciers, with the glacial decline accelerating over the last few decades.
Furthermore, there is about a 30-year lag between greenhouse-gas emissions and the effects that we see today. Although we presently have CO2 levels of 395.7 ppm, the physical evidence we currently see comes from greenhouse gases around 1980, when levels were about 330 ppm. That makes the belief that we can easily reverse climate change through technology change a fallacy.
Greenhouse gases are a serious threat, but we should consider rising greenhouse gas emissions as a symptom of a larger problem–our cultural belief that human population numbers can keep growing without harm, and that those with the means to do so, can continue profligate consumption as if our resources were unlimited.
Alternative energy is not a cure for that culture. If greenhouse gasses were neutralized today, we would still face a myriad of environmental issues that are potentially catastrophic: desertification, deforestation, erosion of topsoil, dropping aquifer levels, destruction of habitat, pollution of water and air, overfishing in the ocean, growing dead spots in the ocean, salination of soils, and the propensity for humans to unthinkingly displace and destroy life. Any resource that we use faster than it can be made will eventually lead to more problems.
Finite resources, of course eventually run out. And even so called “renewable” resources are unlikely to keep up with human numbers, needs, or whimsical consumption. If sustainable means “without negative impact on the future,” then we face many unsustainable problems. So far, we have been able to exhaust one resource and simply move to another. But the Earth is a globe and if we keep gobbling what is in front of us, eventually we will arrive at our own back door.
Dr. Brian Miller is the director of the Wind River Ranch in New Mexico which seems to study and reestablish keystone species. He received his Ph.D. from the U of Wyoming studying black footed ferrets.
George Wuerthner is the Ecological Projects Director for the Foundation for Deep Ecology and has published 35 books, including soon to be released Energy: Overdevelopment and the Delusion of Endless Growth.