Quote:
Originally Posted by simon
Got to love the global warming deniers graphs! Notice that the graph ends just after 1980. Why is that? Because the relationship between length of solar cycle and temperature broke down then.
|
Congratulations! You are the first to call the authors deniers. Nobody denies global warming. They made their study for the time between 1850 to 2000 (the time of publication was 2001) and because they used averaging techniques for the graph, they skipped the first and last ten years to avoid unreal artefacts. I don't know what you have to complain there.
Quote:
Originally Posted by simon
Argos' figures for emissions from volcanic activity are about right, but his figure for human emissions are 1000 times too low. Our emissions are 7 Gigatons, not 7 Megatons, and they're about about 100 times the emissions from volcanoes.
|
You're right, big mistake, obviously I got lost during converting units. Thanks for clearing *embarrassed*
Quote:
Originally Posted by simon
It's also incorrect that the rise of CO2 is constant. A few years ago it jumped to over 2 ppm per year and has stayed there. The reason is not known, but it suggests that positive feedbacks are beginning to kick in.
|
Well, I oversimplified a bit. The average of the last 50 years would be 1.5 ppm - in reality the slope of the accumulation increases constantly, but this can be seen since the last 'little ice-age' at the end of the 16th century. Whatever is the reason, it has to be in the past, not the present.
Quote:
Originally Posted by simon
It's complete nonsense that plants and animals have a high ability to adapt to higher temperatures. If that were the case you should find all the polar and temperate species living in the tropics as well, but you don't.
|
The colonization of Australia is a good example, that adaption from species of cool temperate climate to a much hotter climate is not a big problem. You can easily plant most of your plants at home in UK into a tropical country without serious trouble, whereas to transplant in arctical regions it's often very difficult, if not impossible. The main adaption problem is competition, which is dramatically increased in tropical regions, not so much the climate.
Quote:
Originally Posted by simon
The difference in global temperature between the middle of an ice age and an interglacial like we're in now is 5-6C. It takes about 5000 years for that change to take place. That's a rate of 1C per thousand years.
In the last 30 years the average global temperature has increased by 0.6C. That's a rate of 1C per 50 years. It's 20 times faster. It's been shown that climatic zones are shifting polewards much faster than most species can move. The rate is expected to increase over the course of this century unless our emissions fall a great deal. The climate models predict that the Earth will warm by at least a few degrees over the century. We're talking about getting on for the difference between an ice age and an interglacial, not in 5000 years, but in 100. It's the sheer speed of the change that's the big problem.
|
As for the speed of temperature increase, here is a quote from the NCDC on abrupt climatic changes in the past:
Quote:
...the climate system has changed in the past in ways that are much larger and faster than anything we have observed in the last few centuries or estimated over the past 10,000 years. Most of these changes involve major rearrangements of the ocean-atmosphere-land-ice system.
During a brief period called the Younger Dryas, after temperatures in most of the Northern
Hemisphere had begun to warm from the last ice age, they rapidly returned to near-glacial
conditions. After about 1,000 years, they abruptly warmed again, with temperatures in Greenland warming by eight degrees Celsius (+14°F) in a decade. By comparison, the change in the global mean annual temperature over the last 140 years has been less than 1°C...
|
For reference
We can't blame everything on industrial revolution and exploitation of natural ressources. Things we see now, have happened numerous times before. The predictions of climate models are based on small data sets with significant lack of data for the oceans (currents, salinity, acidity, vertical distribution of their values and influence of it's biomass), the formation and energy balance of clouds (serious research begun only recently) and turbulances in the atmosphere are studied not well enough to come to firm conclusions about the future. At least nice mathematical playing around!