evidence: More than 90% of climate scientists have concluded that human-caused global warming is happening. It is well-established that human activity is the dominant cause of the warming experienced over the past 50 years. This conclusion is based on multiple lines of evidence, from basic physics to the patterns of climate change through the layers of the atmosphere. The warming of global climate and its causes are not matters of opinion, they are matters of scientific evidence, and that evidence is clear. [...] The vast majority of published climate science papers in the 1970s were related to the same concern that prevails today: warming due to the increase in heat-trapping gases. There were a few papers published at that time on the issue of particle pollution (mostly from coal plants which did not yet have scrubbers) blocking out some of the incoming sunlight and exerting a short-term cooling influence. Some media outlets picked up on this and sensationalized the notion of global cooling, contrary to the concerns of most climate scientists. Because it has been a persistent myth that scientists warned of cooling in the 1970s, researchers examined this question and published their findings in 2008 in the Bulletin of the American Meteorological Society. They concluded: "There was no scientific consensus in the 1970s that the earth was headed into an imminent ice age. Indeed the possibility of anthropogenic [human-caused] warming dominated the peer-reviewed literature even then."