The main objections to this theory have been made by...
Global warming is real
Research has led to an overwhelming consensus among climate scientists that climate change, a result of increased greenhouse gas concentrations, is a real, anthropogenic phenomenon being driven by fossil fuel emissions. Data from multiple sources seem to point to the same conclusion. Average temperature indicators since the Industrial Revolution as well as increasing intensity of weather patterns in recent years, and historical trends in levels of greenhouse gases in the atmosphere have convinced well over 90% of the scientific community that global warming is happening now and, if left unchecked, could be catastrophic for the biosphere. The main objections to this theory have been made by skeptics who tend to be unqualified or biased; most of these "scientists" have financial interests in the oil industry or their research was funded by oil executives such as the Koch brothers. In fact, even some of this oil-subsidized research has concluded that, in fact, this is a real issue. Many people, particularly conservatives in the US, tend to deny climate science, however these objections are almost entirely self serving and should be rejected: they are simply wrong.