Conclusion

The past “Big Five” events were mostly caused by physical reasons, for instance, climate change, sea level fluctuation, volcanic eruption, and asteroid impact. Those causes are the most different points with the Six Mass Extinction--it is on its way. 

It cannot be denied that this event is actually caused by human influences, including human activities’ impact on climate change, which leads to rate of the extinctions faster than the average during a mass extinction. If the current path continues the Six Mass Extinction would certainly take place on the Earth in the next few centuries. 

However, the world is still relatively early in the process, therefore, there is still enough time to turn towards and stop the huge loss in biodiversity though it is a difficult task. If the task fails, millions of years are required for the Earth to recover from this human-caused mass extinction so it is urgent to relieve the pressure, which pushes the current’s species towards devastation. 

Are we facing the sixth mass extinction?

So far throughout this blog I've made my attention on the view of the 6th mass extinction. Are we facing the sixth mass extinction? 

Here is a post from other's blog that stated as the extinction rate growing faster and faster, the 6th mass extinction was underway. 

The link is:

http://knsajk.blogspot.co.uk/2011/05/holocene-extinction-on-horizon.html

Besides, here is a video, which made a conclusion to the report "Has the Earth's sixth mass extinction already arrived?". The opinion of the video is to deny that the 6th extinction is underway. However, if we lost most the species that are on the verge of extinction, the extinction event will take place on Earth.

In my opinion, I prefer the point mentioned in the video. That is, we are not in the stage of the 6th mass extinction. But we are near it as if we continue the activities that pollute the environment and destroy the ecosystem, it will lead us to the 6th mass extinction. Therefore, we have to make changes.

What is 6th mass extinction?

Anthony Barnosky, the curator of the Museum of Paleontology at UC Berkeley said that species go extinct all the time. However, new species also evolve constantly. This means the biodiversity always remains constant. A mass extinction will take place when this balance is broken.[1] 
For the 6th mass extinction, Dr Richard Leakey, the world's most famous paleoanthropologist has explained that[2]
"It's the next annihilation of vast numbers of species. It is happening now, and we, the human race, are its cause. The statistics show that about 17,000 to 10,000 species die out every year from Earth which are at a rate comparable with an impact of a giant asteroid slamming into the planet, or even a shower of vast heavenly bodies."
Besides this, there are also many arguments on the six mass extinction event. Niles Eldredge mentioned one is to divide this event into two discrete phases[3]--

(1). The first phase started about 100,000 years ago when the first modern humans began to disperse to different parts of the world.                            

(2). The second phase started when humans turned to agriculture about 10,000 years ago.
This opinion is for we are in the middle of the extinction event as well. 

Reference:

1.http://www.livescience.com/13038-humans-causing-sixth-mass-extinction.html
2.http://www.mysterium.com/sixthextinction.html

3.http://www.actionbioscience.org/newfrontiers/eldredge2.html