Earth’s climate undergoes regular changes. Evidence for this exists in the many historical ice ages and the intervening warm periods as identified in geological and fossil records. In the last several decades, scientists have identified two different types of climate change: rapid climate shifts and long-term changes. Long-term changes are those that happen slowly, normally over tens of thousands of years. Rapid climate shifts, however, can occur in less than a single decade. Both occur naturally.
Science already identified the two causes for all climate changes: internal and forcing. Internal causes are processes that occur as part of the natural climatological chaos (e.g., oceanic oscillations and meteorology). We now understand planetary climate is based at least partially on chaos theory. This demonstrates that eventually the interaction of all climate variables causes random events that act together to cause modifications to normal weather patterns. Over time, cumulative processes interact and eventually cause (assumedly) random changes in the whole system and, subsequently, in the global climate. Forcing, on the other hand, is the interaction of external stimuli such as volcanic eruptions, solar variability, and the planet’s own orbital changes and wobbles. Science, nonetheless, could not determine if rapid shifts were the result of one or both of these controls.
Approximately 8,000 years ago, the last great climate change occurred, bringing to an end the most recent ice age and giving rise to our current “warm” environment. It is strongly believed that the ice age ended because of normal long-term climate changes. The reason for this warming is still unknown, but evidence indicates that immediately following the end of the ice age Earth experienced a rapid and geologically brief “cooling” period. This rapid cooling shift has vexed scientists trying to determine whether it was internal or forced. Had some cataclysmic event caused abrupt decreases in temperatures around the globe, or had the preceding ice age’s last breath caused this temporary cooling?
Climate modelers have now determined that the climate “hiccup” immediately following the end of the ice age was in fact a rapid climate shift. The models used consistently demonstrated the exact changes identified and were wholly validated through comparison to the historical record available from climate proxies. What caused this sudden change in the climate?
Much like the poorly dramatized story as told in The Day After Tomorrow, climatologists have confirmed the post-ice age cooling was in response to a massive freshwater pulse into the North Atlantic from two ancient meltwater lakes known as Agassiz and Ojibway. As temperatures slowly increased over the thousands of years prior to their eventual release, glaciers across North America gradually receded. Their retreat opened a route for these two lakes to “suddenly and catastrophically drain from the middle of the North American continent” into the Atlantic. “Scientists believe that the massive freshwater pulse interfered with the ocean’s overturning circulation, which distributes heat around the globe.” This, in turn, caused global changes in the climate. The importance of these findings is multifold.
It explains in detail the rapidity with which climate changes can occur based on the natural forces of our own planet. Abrupt environmental changes were long thought the result only of forcing, most notably identified by massive volcanic and supervolcanic eruptions as well as large meteorite impacts, to name a few causes. This new discovery clearly shows that rapid shifts in the climate can be the result of internal forces of the climate itself.
The model also provides significant insight into existing climate models and techniques and is already supplementing and even supplanting those simulations that have yet to accurately produce verifiable results. In addition, the new model’s success is adding to our ability to represent accurately present and future global climatology. While the chaotic nature of atmospheric physics prohibits all but the most rudimentary of forecasts, the accuracy of this model’s predictors in relation to past events increases confidence in the validity of future model projections.
As a personal note, many of you already know my abhorrence of the “global warming” lunacy. I cannot deny that the possibility of human-induced environmental changes is cause for concern. I also cannot deny that there remains a legitimate scientific concern that industrial activities may play a part in climate change through greenhouse gas emissions and pollution. That said, nothing in the existing science or math demonstrates that this is true or that it is happening. Sure, you can make assumptions, and many have done just that, but doing so is not scientific and only gives way to doubt and suspicion of scientific methods and findings. This particular success shows that we still have a very limited and immature understanding of our own planet’s climate. It also demonstrates a chaotic system which is capable of both rapid and long-term changes induced by both internal and external stimuli. I think it’s imperative that those claiming to be scientifically inclined cease their panic mongering and focus on the facts and the truth as we currently know and understand it. Doing otherwise is a disservice to science, a disservice to the truth, and an unforgivable disservice to laypeople who rely on scientists to provide objective, honest, and accurate findings sans personal agendas and opinions.