[Thor]

The best go to for all your questions or doubts about man made climate change:

http://www.skepticalscience.com/argument.php

another great resource:

http://grist.org/series/skeptics/

and this great quick summary on Bill Moyers site:

http://billmoyers.com/2014/05/16/eig...al-scientists/

7. Yes, It’s Been Warm Before

Katharine Hayhoe
Director, Climate Science Center, Texas Tech

Katharine Hayhoe, director of the Climate Science Center at Texas Tech, says that on three occasions she came down with food poisoning after eating at a certain chain restaurant. For some reason, she tried the chain again, and once again suffered from the exact same stomach pains the next day. She assumed that she was dealing with another bout of food poisoning, but it didn’t go away. Finally, after two weeks, she discovered that she was actually pregnant — it was morning sickness.

“Just because something happened before for one reason, doesn’t mean that when it happens again it’s for the same reason,” says Hayhoe in response to a claim, popularized by “Lord” Monckton, that the fastest warming ever recorded occurred in central England in the 17th century. This, says Monckton, was before the industrial revolution began, so “it cannot have been our fault.”

“Our planet is running a fever,” says Hayhoe, “and I can think of six or seven reasons why it could be running hot. As a scientist, you don’t just jump to conclusions. You do the tests. You say, ‘OK, could it be a natural cycle this time? Could it be the sun? Could it be volcanoes? Could it be orbital cycles and ice ages?’ We run those tests and we see if it could be any of those things that caused the climate to change naturally in the past. And in this case, we’ve run those tests and the answer to all those questions is, ‘no.’ In fact, if our temperature were controlled by natural causes right now, we’d be getting cooler, not warmer.”

Hayhoe also notes Monckton’s reliance on temperatures in Central England during odd ranges of dates, like 1663-1762. “It’s cherry-picking in both space and time,” she says. “If you’re going to look at global climate change, you have to look at global temperatures. When it’s hot in one place, it’s cold in another. And when you see weird dates, you should be suspicious — there has to be a reason why someone chose those odd dates. Climate scientists tend to use nice round numbers like 1800 or 1900.”