16 2050. The doubling would bring about dramatic changes in the world's environment.” Among these, the appendix states, “ocean levels would rise four feet.” Also, “the melting of the polar ice caps…could trigger major increases in earthquakes and volcanic activity resulting in even more atmospheric CO2 and violent storms. The Arctic Ocean would be ice free for at least six months each year, causing major shifts in weather patterns in the northern hemisphere. The present tropics would be hotter, more humid, and less habitable….” At a 1984 Exxon/Esso environmental conference, Exxon scientist Henry Shaw’s presentation noted that “a 2 to 3 °C increase in global average temperature can be amplified to about 10 °C at the poles [30]. This could cause polar ice melting and a possible sea-level rise of 0.7 meter by 2080. The time scale for such a catastrophe is measured in centuries. Other potential effects associated with a high atmospheric CO2 concentration and a warmer climate are: - redistribution of rainfall - positive and negative changes in agricultural productivity - accelerated growth of pests and weeds - detrimental health effects - population migration” • Non-peer-reviewed documents offer a mix of positions. Among the documents that take a position, 45% ‘Acknowledge’, 41% ‘Doubt’, and 14% ‘Acknowledge and Doubt’. Several of the expressions of doubt in non-peerreviewed documents reflect the industry-targeted communications included in this category. An example of acknowledgment is a 1997 book chapter coauthored by Exxon scientists, which acknowledges that “Although model projections of a warmer Earth are uncertain, it appears that the intensity and tracks of storms may change. In addition, it has been suggested that severe storms such as hurricanes may increase in frequency and/or intensity...Projections suggest a potential sea level rise of up to about 1 m by 2100” [59]. A 2014 report, “Addressing adaptation to climate risks in the oil and gas industry,” discusses “a range of risks from current and future climate variability” faced by the industry, such as “changes in storm strength” [60]. • ExxonMobil advertorials overwhelmingly take the position of doubt. Of the advertorials that take a position, 62% express ‘Doubt’. Most of the remainder express a mixed position (24%). Often, they express the opinion that concern over climate impacts is alarmist, such as a 1995 advertorial entitled “The sky is not falling,” which asserted, “The environment recovers well from both natural and man-made disasters” [61]. “Just as changeable as your local weather forecast,” says a 2000 advertorial, “views on the climate change debate range from seeing the issue as serious or trivial, and from seeing the possible future impacts as harmful or beneficial” [62]. Another advertorial in 2000 states that “Some use [the 1 degree Fahrenheit rise in Earth’s surface temp over the past 150 years] to claim that humans are causing global warming, and they point to storms or floods to say that dangerous impacts are already under way. Yet