We don’t know what drives the Earth’s climate.
There are a large number of natural and man-made factors we know of, and probably some unknown factors, that are all believed to cause climate change.
The largest climate effects seem related to long term changes in the Earth’s orbit -- orbital eccentricity, obliquity and precession.
Many Earth Cycles Affect Climate:
100,000-year elliptical orbit cycle
41,000-year axial tilt cycle
23,000-year precession (wobble) cycle
1,500-year solar-driven climate cycle
.
Ice core studies show the 1,500-year (+/-500 years) Dansgaard-Oeschger global climate cycle has existed on Earth for at least the past one million years, in times when atmospheric CO2 was high, and low.
The 41,000-year obliquity cycle is a change in the Earth’s axial tilt.
Precession controls the distance from the sun during the seasons.
Currently the sun is closest to the Earth in the northern hemisphere winter.
This moderates northern hemisphere winters and makes southern hemisphere winters more severe.
Both obliquity and precession changes seem to cause and end major periods of glaciation.
The seasons change more when Earth's axial tilt is high (24.5°) than when the tilt is low (22.1°).
The current tilt is intermediate at 23.5°, but is decreasing rapidly.
What does this have to do with the IPCC ?
The UNs Intergovernmental Panel on Climate Change (IPCC) could not care less about natural causes of climate change, which have existed for all 4.5 billion years of Earth's life.
The goal of the IPCC was to prove that man made carbon dioxide (CO2) is an evil gas.
But real science doesn’t prove things.
Real science falsifies hypotheses.
If the IPCC practiced real science, their starting point would have been demonstrating that the change in Earth's average temperature over the past 135 years was unusual.
But it was not unusual -- the climate was quite stable, and remained in a small one degree C. range (with a reasonable margin of error of at least +/- 1 degree C. , the temperature change since 1880 is from zero to +2 degrees C.)
The IPCC falsely claims humans began controlling the climate after 1940, and that rising man made CO2 became the climate controller.
Never mind that there was no warming half the time from 1940 to 2015.
- No warming from 1940 to 1975 (25 years).
- No warming from 2003 high to 2015 low (12 years).
That adds up to no warming for 25 years + 12 years
= 37 years.
37 years with no warming is half of the total of 75 years from 1940 to 2015.
If CO2 really controlled the climate, then why do CO2 levels go up every year, with no global warming half of the time?
The IPCC is made up of people who voluntarily associate with it because they find it supports their professional interests.
The IPCC heavily influences the grant-making process that determines what scientific research gets funded, and what does not.
IPCC members and supporters attack scientists who accept funding from any organization who is undecided about, or does not agree with, the fantasy that a 'climate catastrophe' is currently in progress.
The IPCC actually publishes socialist public policy disguised as science.
Their "solution" (to a non-existent climate problem) is always bigger government, less personal freedom, less prosperity, and lower personal energy usage.
The IPCC was set up and staffed in response to a pre-existing “conclusion”.
The pre-existing conclusion was that human emissions of carbon dioxide are almost entirely responsible for global warming.
The IPCC was set up ONLY to “prove” that pre-existing conclusion was right.
But their "proof" consisted of wild guess computer games (models that prove nothing, because they have had no predictive ability for the past 40 years).
The UN goal was to tell the world how to reduce what is now erroneously called “carbon emissions.”
The IPCC was not set up to determine anything important, such as:
(1) What causes climate change?
(2) What causes global warming?
(3) What is a “normal” average temperature?
(4) Has the change in average temperature since 1850 been abnormal?
(5) How accurate are estimates of the average temperature since 1850?
(6) Is the current climate harming humans, animals and/or plants?
(7) Is climate change harming farm productivity?
(8) Are sea level changes endangering humans?
Background information for IPCC
https://web.archive.org/web/20140108192827/http://unfccc.int/essential_background/convention/items/6036.php
If the “carbon dioxide is evil” assumption was actually true, then the UN might have been the organization to “police” worldwide emissions of carbon dioxide.
And that would have been the first step toward building the UN into a ‘world government’.
Any suggestion that the IPCC is a “climate science” organization is wrong.
REAL scientific investigations do not begin with a conclusion (CO2 is evil) that will never change, especially a conclusion that makes no sense.
REAL scientific investigations do not ignore all evidence contradicting the conclusion.
REAL scientific investigations do not rely on personal wild guesses of the future climate, disguise the wild guesses as complex computer models, and claim their computer games are proof that CO2 is evil !
I say the IPCC conclusion that man made CO2 controls the climate “makes no sense” for two good reasons:
(1) There is no evidence in 4.5 billion years of climate history that CO2 has ever controlled the climate, and
(2) There is no evidence CO2 suddenly took over as the ‘climate controller’ in 1940 !
The IPCC is 99% biased leftist politics, and 1% unbiased climate science.
That is just what I would expect coming from the UN -- an organization so deluded that it claims the most evil nation in the world is ... Israel !