Key Concepts: At this point it is too late to avoid the impact of climate change on human society. That doesn't mean we should give up. Instead, it reinforces the importance of making wise, scientifically-informed choices about our present and future actions. We need to recognize what aspects of our lives, societies, and technologies can mitigate the affects of global climate change, and what aspects can adapt to these changes. We need to build resilient communities, technologies, and societies to weather the changes ahead in a positive fashion.
Let's revisit the quotes from the lecture notes at the end of last semester:
- "With inadequate preparation, the result [of abrupt climate change] could be a significant drop in the human carrying capacity of the Earth's environment."
- "The consequences of even relatively low-end global climate change include the loosening and disruption of societal networks. At higher ranges of the spectrum, chaos awaits."
- "Each year we delay action to control emissions increases the risk of unavoidable consequences that could necessitate even steeper reductions in the future, at potentially greater economic cost and social disruption."
No, these are not from publications by Al Gore, the Sierra Club, or other "left-wing" or "environmentalism" groups. They are, respectively, from An Abrupt Climate Change Scenario & Its Implications for United States National Security: Imagining the Unthinkable, a 2003 report by the Global Business Network for the Pentagon; The Age of Consequences: The Foreign Policy and National Security Implications of Global Climate Change (a 2007 joint report of the Center for Strategic and International Studies and the Center for a New American Security); and A Call to Action, a 2007 report by the U.S. Climate Action Partnership, a coalition of environmental groups and corporations from a number of industries including Chrysler, Dow, DuPont, Ford, General Electric, General Motors, Johnson & Johnson, PepsiCo, Shell, and Weyerhaeuser. So there are very much establishment, industrial, "right-wing" institutions who take the reality of climate change quite seriously.
A recent blog-project has started asking climate researchers to express what their knowledge of climate change makes them feel: it is worth checking these out.
Last semester we documented the science behind climate change: how the Earth systems work; how certain human technologies (as well as plenty of natural phenomena) perturb them; and how these changes impact upon human and natural systems. This semester we will see how Science can be employed to deal with the issues of climate change. In other words, how can Science help us become Resilient in the "Age of Consequences"?
Resiliency
The last few decades have shown an emphasis on sustainability, the ability to continue a defined desired behavior (say, feeding human populations) indefinitely. This is all well and good, but the problem has been defining the parameters of sustainability in a world with a changing environment. Simply put, "sustainability is not sustainable": that is to say, most particular practices claimed to be sustainable were not developed to cope with changing parameters.
So the move has come to think about sustainability in a new way: as resiliency. Resiliency is defined in this context as:
- The ability to absorb stresses and maintain function in the face of externally imposed stresses; and furthermore:
- The ability to adapt, reorganize & evolve into more desirable configurations that improve the sustainability of the system
This semester we will explore some issues of resilient technologies and practices; we hope you continue to do so throughout your life.
Humans as Unintentional Agents of Change
Let us remember some of the main ways humans affect the Earth systems:
- Introduction of greenhouse gases (and thus increasing the Earth's "blanket") primarily through the use of fossil fuels, but also from farming, from concrete production, and as positive feedbacks from increased temperatures melting permafrost (and eventually methane clathrates)
- Capture of a sizable fraction of the biosphere to feed ourselves directly or indirectly; as a consequence, the amount of wildlife is comparably produced and less diverse
- Utilization of substantial fractions of the freshwater systems of the world
- Globalization of flora and fauna (including disease vectors and pathogens)
- Increasing ocean acidification (due to increased carbon dioxide) and sea level (due to thermal expansion and melting of glacial ice)
- Generation of excess fixed nitrogen and other fertilizers, leading to oceanic dead zones
In many of these aspects, humans equal or exceed natural (non-anthropogenic) fluxes.
How long lasting will these changes be? This requires examination of the Earth systems themselves, both from the paleo-record and from modeling these systems. Some of the main conclusions:
- David Archer and colleagues have shown that it will take centuries
to tens-of-millenia for the natural oceanic and lithospheric systems to resorb the totality of the greenhouse gases
released. Recall our look at entropy in the first semester: it takes a lot longer to build up a tree storing chemical energy
than it takes to release it in a fire. This is a similar situation: burning is fast, while chemical binding and sedimentological
sequestration takes literally geologic time scales. In other words, we could stop burning all fossil fuels immediately, and we
would still have a sizable fraction of the anthropogenic carbon dioxide in the atmosphere for many times longer than
written history has existed so far.
- Add to this the complication that much of the carbon dioxide, and the heat, already released is in the mixing zone of the oceans, so that it will continued to be released (by degassing and radiation, respectively) for millennia even if/when we stop emitting.
- Ditto for permafrost and methane clathrates. And should the clathrate gun be triggered...
- The Paleocene-Eocene Thermal Maximum we examined last year similarly showed that it took 10s of thousands of years for that (slower, but comparable in scale) burst of greenhouse gases to be resorbed.
- The PETM also showed the effects of a smaller-scale globalization of flora and fauna than the anthropogenic one. The combination of this and the burst of climate extremes resulted in a moderate scale mass extinction. However, other factors (our capture of a good fraction of the biosphere; land development; oceanic dead zones; ocean acidification) all point towards a mass extinction on the scale of the larger ones in Earth's history. The fossil record shows that it typically takes millions to 10 million years or so for the survivors to evolve into the lost niches of the extinction victims.
Consequently, the hopes of much of the environmental movement are pipe dreams: even the immediate cessation of all industrial activity (or even the magical vanishing of the human race as a whole) would not result in a world that looked like the pre-industrial one. Too much has happened, and too much will continue to happen, for the world to be restored to some kind of idyllic "pristine" condition.
And, of course, we (hope!) that we aren't going anywhere, but instead will continue to inhabit this planet. To do so we still need to feed and water our bodies; power our industries; maintain our infrastructure; and hopefully live lives at a reasonably high quality of life for as many people as possible.
As we saw last semester, global changes have already, and will continue to affect us, through:
- Disruptions of freshwater and food availability
- Disruptions of travel and commerce
- Disruptions of economy by (among other things) requiring work on infrastructure to deal with rising sea levels, storms, etc.
- Environmental refugees
- And, in extreme conditions, war and other conflicts brought on by stresses from the above
Or, in other words, people have to stop thinking about global change as an "environmental issue", because in
politics and civic life environmental issues are thought of as niche issues that we can get to when we have time.
It clearly is not. It is essentially a national security (or international security, really) issue. This video
puts it well:
So we have to deal with the consequences of the actions so far, and plan for our futures with consequences in mind.
