Ice ages occur in about 100,000 year cycles.
Changes in the eccentricity of the earth's orbit are the driving factor.
When the orbit is very eccentric, an ice age occurs.
When the orbit is more circular, we have an inter-glacial.
That's what's happening now.
It will be a few thousand years before we can expect natural causes to drive the climate toward cooling, and a new ice age.
http://en.wikipedia.org/wiki/Milankovitc...
In the graph, note how ice age cycles line up with eccentricity cycles.
Here's a more complete description of the cycles. However, keep in mind that the ice ages fairly accurately line up with the eccentricity cycles.
http://www.eoearth.org/article/Milankovi...
And a brief general synopsis.
http://geography.about.com/od/learnabout...
What we're seeing today is unprecedented.
We're burning fossil fuel that has been sequestered over hundreds of millions of years.
That is causing changes in both the oceans and the atmosphere, at a rate, that haven't been seen in the last 65 million years.
http://news.stanford.edu/news/2013/augus...
In fact, what is happening today has been called by some the latest mass extinction.
http://www.livescience.com/13038-humans-...
Here's what's happening:
http://www.rkm.com.au/ANIMATIONS/carbon-... <== here's the physics.
http://web4.audubon.org/globalwarming/im... <== this is why CO2 is a problem.
http://www.rsc.org/images/CA1_tcm18-1379... <== Word doc. Page 6 shows where H2O and CO2 intercept different wavelengths
http://upload.wikimedia.org/wikipedia/co... <== Note that CO2 intercepts a different wavelength than water. In addition, as CO2 warms the oceans, more water evaporates, increasing it's effectiveness.
I think the question should be how the AGW supporters can distinguish the peas of human activity through the mattresses of natural climate variation. (An apt comparison given the relative volumes of energy and matter handled.)
While the computer climate models AGW supporters rely on are based on insufficient data, they do raise a valid point. Since we don't know what the effects of adding carbon dioxide actually are, it might be wise to develop the means to inexpensively remove it should we wish to. I favor Iron fertilization:
http://en.wikipedia.org/wiki/Iron_fertil...
which emulates sporadic natural iron fertilization events in the oceans causing diatoms
http://en.wikipedia.org/wiki/Diatom
(microscopic plants that form a siliceous shell around their carbon using internal chemistry)
These shells make them resistant to being eaten when alive or dead (by decay bacteria) and far more likely to sink to the bottom carrying their carbon content with them, as they already do in the Biological Pump
http://en.wikipedia.org/wiki/Biological_...
which already naturally gets rid of a significant amount of carbon (carbon sequestration)
http://en.wikipedia.org/wiki/Carbon_sequ...
There are objections raised against this option, which would disappear on thoughtfully reading some of the articles above.
You're basically adding a needed nutrient as nature does to grow plants that occur naturally and will sink quite naturally as the ocean sea beds have long shown:
http://en.wikipedia.org/wiki/Pelagic_sed...
Developing an understanding of how to do this follows the precautionary principal. The time to develop a parachute is before you need to leave the plane.
They can barely explain how a net change in our atmosphere of 0.004% can cause any measurable warming. They have a hard enough of a time explaining to the world how their temperature anomalies are a direct depiction of actual temperature. 10ths of a degree warming is their signature achievement, but they can't quantify (define 'how much') the net change of atmospheric CARBON in over 350 years as the cause. Try changing the whole atmosphere of a real plant greenhouse by 0.004% and see what kind of temperature change you can get. Use any molecule that you can "float" in the atmosphere with 2 oxygen (or more) atoms.
Mostly it is CO2. CO2 has always been a driver of global climate.
Milankovitch Cycles amplified by changes in CO2 levels.
without the greenhouse effect earth would be in a constant ice age.
the fossil fuel industry pays people to lie
,during which the earths temperature and CO2 levels reached todays levels, and explain why todays levels are not being caused by the same?
I have no proper concept about the Question.
The Milankovitch Cycles.
Anyone who finished K12 successfully should know that.
They can't because global warming is a natural thing, very very little of it is from pollution.
Milankovitch Cycles...
https://www.nc-climate.ncsu.edu/edu/k12/...
Note that this has nothing to do with anthropogenic global warming. Nor does it mean that anthropogenic global warming does not exist.
