Countering Ice Ages: Re-directing Public Concern from Global Warming (GW) to Global Cooling (GC)

I present here three arguments in favor of such a drastic shift -- which involves also a shift in current policies, such as mitigation of the greenhouse (GH) gas carbon dioxide.

1. Historical evidence shows that cooling, even on a regional or local scale, is much more damaging than warming. The key threat is to agriculture, leading to failure of harvests, followed by famine, starvation, disease, and mass deaths.

2. Also, GC is reasonably sure, while GW is iffy. The evidence from deep-sea sediment cores and ice cores shows some 17 (Milankovitch-style) glaciations in the past 2 million years, each typically lasting 100,000 years, interrupted by warm inter-glacials, typically around 10,000-yr duration. The most recent glaciation ended rather suddenly about 12,000 years ago. We are now in the warm Holocene, which is expected to end soon. Most of humanity may not survive the next, inevitable glaciation.

We need to consider also the warming-cooling (Dansgaard-Oeschger-Bond -- DOB) cycles, which seem solar-controlled and have a period of approx 1000-1500 years; its most recent cooling phase, the “Little Ice Age” (LIA), ended about 200 years ago. For details, see Unstoppable Global Warming: Every 1500 years by Singer &Avery [2007].

3. Available technology seems adequate to assure human survival -- at least in industrialized nations. The main threat is warfare, driven by competition for food and other essential resources. With nuclear weapons and delivery systems widely dispersed, the outcome of future wars is difficult to predict.

Using geo-engineering to overcome a future cooling looks promising for both types of ice ages -- with relatively low cost and low risk to the physical and biological environment. I will describe how to neutralize the “trigger” of major glaciations, and propose a particular greenhouse scheme that may counter the cooling phase of DOB cycles.