In his new book the 'The Weather Makers' (Text Publishing, Melbourne, $32.95) Professor Tim Flannery suggests that the medieval warm period was unique to Europe with "a survey of global temperature records (from ice-cores, tree-rings and lake deposits) showing that, if anything, Earth was then overall slightly cooler (0.03C) than in the early and mid twentieth centuries". This according to Flannery shows that the "idea of a global Medieval Warm Period is bunk." (pg 44)
The real bunk is perhaps Flannery's claim that the world's leading science journals are telling us that species are vanishing right now as a consequence of climate change. (pg 6)
He is a good writer though, and there is some interesting stuff in the book including his comment there are three agents of change:
1. shifting continents,
2. cosmic collisons and
3. climate-driving forces such as greenhouse.
Flannery writes that while they all act in different ways, they drive evolution using the same mechanisms "death and opportunity". (pg 46)
Whatever happened to the "precautionary principle"?
Taught in environmental courses and advocated by natural resource practioners. If we applied that principle to climate change, we would need to park our cars and close down coal-fired power stations.now.
As Phil says, the alternative is pretty permanent
Whatever happened to the "precautionary principle"?
Taught in environmental courses and advocated by natural resource practioners. If we applied that principle to climate change, we would need to park our cars and close down coal-fired power stations.now.
As Phil says, the alternative is pretty permanent
The solubility of CO2 in water varies inversely with temperature, so as the oceans warm, CO2 is lost to the atmosphere, not the other way round. How can oceanic CO2 levels INCREASE, and cause a lowering pH (increased acidity) in ocean water, if its temperature goes up? PLease explain!
And what were methane levels?? And regardless, the real problem is how the increase in CO2 are causing the oceans to become more acidic.
And the orbital forcings were ?
And the position of the tectonic plates - Pangea etc - were what and where .... at what latitudes (getting what solar forcing) moving where ....
Flora and fauna were what ?
May have been a few other differences perhaps ...
You tell me what these other influences would have been up to ? (i.e. I'm not totally sure)
But Rog - all very interesting nonetheless and thanks for bringing it up ....
More on CO2 and atmosphere, it appears that fossils from the carboniferous period indicate an atmosphere of much increased CO2 with the same climate as today;
"Average global temperatures in the Early Carboniferous Period were hot- approximately 22° C (72° F). However, cooling during the Middle Carboniferous reduced average global temperatures to about 12° C (54° F). As shown on the chart below, this is comparable to the average global temperature on Earth today!
Similarly, atmospheric concentrations of carbon dioxide (CO2) in the Early Carboniferous Period were approximately 1500 ppm (parts per million), but by the Middle Carboniferous had declined to about 350 ppm -- comparable to average CO2 concentrations today!
Earth's atmosphere today contains about 370 ppm CO2 (0.037%). Compared to former geologic times, our present atmosphere, like the Late Carboniferous atmosphere, is CO2- impoverished! In the last 600 million years of Earth's history only the Carboniferous Period and our present age, the Quaternary Period, have witnessed CO2 levels less than 400 ppm."
http://www.geocraft.com/WVFossils/Carboniferous_climate.html
Also in the letters section of The Land is this piece;
'Inexact Science' Bruce Gardiner from Armidale writes
"I cannot let Jennifer Marohasy's article go unchallenged.
From its tenor, one gains the impresssion that science is "exact". This is not the case. Science is, by nature, reductionist. It provides insights into what happens to one variable if all others are held constant...."
....."Agricultural production is being maintained by increasing inputs of finite resources at non-sustainable levels. Can we afford to follow this experiment to the point where global systems collapse just to prove that what we are doing is not sustainable?
Personally I think that if there is even a one percent chance that what we are doing is not sustainable, then we should adopt a precautionary approach and assume that it isn't. The alternative is pretty permanent".....
A one percent chance is sufficient in science? No wonder there is a divide in perception...