Global Warming Takes Another Hit

I haven't talked much about global warming on here, but I do not believe that humans are responsible for global warming. I believe that the Earth goes through warming and cooling cycles. I think there is good evidence for this, for example what caused the ice age to begin and end? Was that man made, of course not. So, it must have been a cycle of the Earth.

Some scientists are also questioning handmade global warming too. In the last two days I found these articles.

The first two are about some Japanese scientist who reject the claim that climate change is man made.
Top Japanese Scientists: Global Warming Is NOT Caused By Human Activity
Japan's boffins: Global warming isn't man-made Climate science is 'ancient astrology', claims report

The next one comes from the Discovery Channel, Warming might be on hold, study finds Authors sense hibernation, but warn of 'explosive' rise later, and says that global warming has hit a speed bump. They were predicting a .2 degree Celsius increase in temperature that has not happened and scientists don't know why.

"The discrepancy gets to the heart of one of the toughest problems in climate science — identifying the difference between natural variability (like the occasional March snow storm) from human-induced change."

So they don't know what is natural and what is man made, but at the end what they make perfectly clear is that they are certain that in the end man is the cause of global warming and it will be rapid.

"Swanson thinks the trend could continue for up to 30 years. But he warned that it's just a hiccup, and that humans' penchant for spewing greenhouse gases will certainly come back to haunt us.

'When the climate kicks back out of this state, we'll have explosive warming,' Swanson said. "Thirty years of greenhouse gas radiative forcing will still be there and then bang, the warming will return and be very aggressive."

How are they so certain that the cooling is just a hiccup? Why could it not be the case that the Earth is entering a cooling cycle? How are they so sure of this if they have shown they don't know what they are talking about.