I learned that human activities produce gases that deplete the ozone layer, and create the greenhouse layer, which increases the world's temperature. (And seems real , now in Thailand it's 35 degree Celsius)

Greenhouse Effect occurs

Now. I want to know that if there isn't any human activities that causes changes to atmosphere , Which statement is correct?

  1. The earth will be cool. As the same temperature as before the industries age. It's only human's fault that makes the world hotter.

  2. The earth will be gradually hotter. In the past there are "ice age". And Now there might just be "hot age". Humans activities are just make the process faster.

Can we point out which statement is currently correct? If not , you can add your own statement and if you are able to explain , do it.

  • 2
    $\begingroup$ Do the anwswers at How much of the current global warming is due to human influence? answer your question? If not, why not? $\endgroup$
    – gerrit
    Apr 30, 2014 at 13:39
  • $\begingroup$ @gerrit no. I still want to know that if there is no human , will the temperature still rise? I still need to know also what nature influence the global warming. That answers only say what human do , but not what nature also do. $\endgroup$ Apr 30, 2014 at 14:18
  • $\begingroup$ Answer is the Earth would be cooling if humans were not present; humanity's impact has been only recently, and you can clearly see that for a very long time before our impact that Earth was cooling, not warming. Please read the answer in the other question, and think about what the data says; believe you did, you just don't want to believe what the data says. More to the point, look at this graph, which is in the answer. $\endgroup$
    – blunders
    Apr 30, 2014 at 22:30