Anyone who doubts the first option of the poll has a lot of reading to do and might as well be questioning whether gravity is real. [url=http://iopscience.iop.org/article/10.1088/1748-9326/8/2/024024/meta]A 2013 literature review[/url] analyzed over 4,000 published research papers on the causes of global warming. 97% of all these papers concluded that humans are causing global warming. [url=http://www.slate.com/blogs/bad_astronomy/2012/12/11/climate_change_denial_why_don_t_they_publish_scientific_papers.html]A 2012 analysis[/url] of almost 14,000 scientific papers published over the course of 25 years found that only 0.1% of all these papers rejected that humans had an influence on climate change. [url=http://ipcc.ch/pdf/assessment-report/ar5/syr/AR5_SYR_FINAL_SPM.pdf]The fifth version of the United Nations Intergovernmental Climate Panel[/url] did a review in 2014 of just about all recently available scientific findings in addition to evaluate research by its own members and concluded, without any doubt, that "human influence on climate change is real". [url=http://www.pnas.org/content/107/27/12107.full.pdf]A 2010 overview of research[/url] reviewed publication data of nearly 1,500 scientists and found that 97-98% of all regularly publishing climate researchers were clear in their findings that humans affect and influence climate change. [url=http://onlinelibrary.wiley.com/doi/10.1029/2009EO030002/abstract]A large poll of over 3,000 climate scientists[/url] found a near absolute consensus that climate change is influenced by human activity among those who research and specialize in climatology. [url=http://journals.sagepub.com/doi/abs/10.1177/0270467616634958]A 2015 literature meta-analysis of studies[/url] that covered a staggering 25,000 recent scientific papers by 70,000 researchers found that only 4 authors disagreed with the notion of human-influenced climate change, meaning that literally 99.99% of all scientists researching climate changes in the last few years agree that humans definitely influence climate change. Just to let that sink in for a moment, this means that only [b]0.0058%[/b] of all recently published and peer-reviewed authors on the topic of global warming do NOT think that humans contribute to climate change. [url=http://www.slate.com/blogs/bad_astronomy/2014/01/14/climate_change_another_study_shows_they_don_t_publish_actual_papers.html]Another literature review[/url] of the research done by nearly 10,000 scientists in 2012-2013 concluded that ONLY ONE SINGLE PERSON out of 10,000 researchers (or 0.01%) did not conclude that humans negatively influence climate change. Any person who at this point claims that there is some reason to assume that human behavior is not in one way or another contributing to the climate change we are seeing today, or who tries to push the narrative that there is somehow a balance in research between different findings is both ignorant and uneducated on the issue. We might not be able to accurately determine exactly how much humans have contributed to climate change, but I sincerely hope no one here is actually implying that there is still even the slightest sliver of doubt about whether humanity has negatively affected climate change.