What is "Global Weirding"?
One of the key findings reported at the International Scientific Congress on Climate Change held recently is that we ought to work hard at the restoration of ecosystems and revitalization of ecosystem services, if we want to avert the worst of the climate disaster (see our "Key Messages" post from last weekend).
It’s hardly offering any solace, but if a worst case scenario becomes reality, we’re faced with changes in the order of those that occurred to global mean temperatures in the most recent ice age. No doubt a lot of guesswork is involved in finding out just what the impact of the rapid heating of the atmosphere used to be in Ice Age times, but thanks to (mostly frozen) remnants, researchers are definitely making informed guesses.
One recent study by a European scientist at the Department of Physical Geography and Quaternary Geology in Stockholm reveals how the ecosystem changed during the last ice age, and, more importantly, how it recuperated.
The rapid rise in temperatures during the last Ice Age, which lasted from about 115,000 years to 11,500 years ago, brought about an adaptation of ecosystems at even more rapid speed. The main finding of the study is that the adaptation of the ecosystems prompted by the warmer cycles took place within only 50 to 200 years. “These findings show that ecosystems have changed rapidly in reaction to climate changes in the past, which indicates that quick adaptations could also take place in the future as a consequence of global warming,” says researcher Linda Ampel.
She focused on sediment cores in a lake in France, named Les Echets. Ampel, who conducted the study for a dissertation at Stockholm University, says that several rapid and dramatic climate swings took place in cycles of around 1,500 years.
Swings of 8-16oC of Greenland’s mean temperatures were the order of the day, Ampel asserts. A typical cycle characterized with an extremely rapid rise in temperatures, which would unfold over just a few years or decades.
The study was based on analyses of fossil silica algae, also known as diatoms.These are sediment cores and can be divided into various species, each of which prefers its own water conditions, temperature, salinity, access to nutrients, light, water depth, or available types of places to grow. All of the parameters narrate a story of how climate change will have affected the diatoms.
Ampel’s study is one of a limited number that have studied the pace at which climate change is taking place. Ever since the UN Framework Convention on Climate Change (UNFCCC) was signed in 1992,the emphasis has been on avoiding dangerous anthropogenic interference with the climate system by limiting a rise in temperatures.
Yet the temperature rise is only one side of the coin. The pace at which climate change effects take place is of equal importance. The latest findings of the International Scientific Congress on Climate Change might change this because it leaves little doubt that the expected changes will be faster than the ability of the flora and fauna to adapt. If language is anything to go by, the notion is sinking in that the way rising temperatures are causing species to adapt because the term “global weirding” was recently coined for this very process. Global weirding is also used to describe the way species time their migration and the way they interact with other living things.
The scientists Leemans and Eickhout already pointed out in 2004 that five percent of all ecosystems cannot adapt more quickly than 0.1 °C per decade over time. If the rate is 0.3 °C per decade this level will rise to 15 percent of ecosystems. A 0.4 °C per decade rise will result in the destruction of all ecosystems, the domination of opportunistic species. The breakdown of biological material will lead to even greater emissions of CO2. This will in turn increase the rate of warming.
Scientists say that melting polar ice is even worse, as is be a weakening of the Gulf Stream.
One of the first tangible signs of the devastating effects of rapidly evolving global warming effects are dying forests because trees have limited ability to migrate to safer territory.