Does Global Climate change do the same damage on timeline 1 on earth as timeline 2 which we live on?

 No. Because Civilization ended completely on September 11th 2001 on the first timeline. So, the effects of global climate change don't have the same effects as they do on this timeline.

Why?

It mostly has to do with the number of people and their civilizations pumping out CO2 and hydrocarbons into the air on the 2nd timeline we live on.

Imagine no civilization and the remaining people functioning mostly like wolves or cavemen or cave women and on top of this the radiation degraded human intelligence back to a wolf like State of being. So, even tribal functions are very primitive and all technology is gone. So, even survival to age 30 is remarkable in a tribal group like this with all civilization basically gone and all cities in ruins and no public education or governments beyond wandering tribes and it took about  4000 years to even develop farming once again and a total of about 5000 years to get to where we were around 1500 in the Elizabethan Era with Queen Elizabeth I in England only it was like this in Switzerland because that was a neutral country and didn't get nuked by doomsday weapons from any side because of this on September 11th 2001.

So, No, Global Climate change is not a big factor on Timeline 1 because civilization is completely gone from earth for the next 4000 years from around September 11th 2001 AD until around 6000 Ad there is nothing but campfires to cook and to stay warm. There are bows and arrows eventually and hunting but even farming doesn't come back until around 5000 or 6000 AD.