Why does the fact that previous changes have occurred naturally mean that this warming has to be natural?

Question

Of course the climate changes all the time. But the scientific data clearly shows that this particular warming is not natural.

See:

Meehl, G.A., et al (2004). "Combinations of Natural and Anthropogenic Forcings in Twentieth-Century Climate". Journal of Climate 17: 3721-3727

whose results are summarized at:

http://www.globalwarmingart.com/wiki/Image:Climate_Change_Attribution.png

No theory that contains only natural factors comes even close to matching the observed data.

This is science. "Logical" arguments don't trump data. Neither quantum mechanics nor relativity are "logical". They are accepted by scientists because the results of their calculations match observed data.

"I wasn’t convinced by a person or any interest group—it was the data that got me. I was utterly convinced of this connection between the burning of fossil fuels and climate change.

Vice Admiral Richard H. Truly, USN (Ret.)
Former NASA Administrator and Shuttle Astronaut - a guy who understands data

Can someone post a non-perjorative answer (or edit an existing one) so I can choose it as best answer? One without emotionally loaded words?

I'm looking for an answer in the same measured language as the question.

Answer 1

It doesn't, that would be one of many commonly made logical fallacies regarding global warming.

Answer 2

computer technology and understanding of the climate has increased dramatically over the last 30 years. As each year proceeds the knowledge gained further enforces the AGW theory. Soon 90% certainties will become 100% certainties. I believe the ability to predict climate and maybe even weather with extreme accuracy will be reached within the next 20-30 years.

Answer 3

Do you remember when audio CDs were new? I was pretty slow to accept them. I think it was about 1994 or 5 before I bought a CD and a player. I denied that they were superior to LPs (I'm not that silly anymore) because I simply did not want them to be. I did not want my LP collection to become obsolete.

The climate change deniers are doing the same thing. But don't worry; they are now a small minority on their way to the garbage heap like the flat-Earthers.

Answer 4

the global warming is in a way natural but its happening more quickly than usual.and what's it gonna be........... another ice age but will the human race survive? i saw on discovery e footage about GW and its about the icebergs and i mean if the melting still continues there will be how should i say let loose some deadly viruses which are captive in the polar ice and if they'll escape we are dead. discovery

Answer 5

The data shows that there is some correlation between greenhouse gases and global temperature changes. It does not show that there is a cause and effect relationship. There are periods where greenhouse gases increased and global temperatures decreased or remained constant. This should not be the case in a true cause and effect. There are still too many unknown variables to show that mankind is the cause of the global warming.

Answer 6

Bob, Bob, Bob. (sigh).

Surely you're not expecting LOGIC from global warming skeptics? If these people thought logically, they would have been able to stay awake in science class.