The greenhouse effect is now commonly accepted by the scientific community, politicians and the general public. However, the misnomer 'greenhouse effect' has perpetuated, and there are a number of aspects of the effect which are poorly understood outside the atmospheric sciences. On such misconception is that greenhouse research is a recent phenomenon; another is that glasshouses are warmed by the same mechanism as lies at the heart of the greenhouse effect. This review traces the theory as far back as 1827, highlighting new directions and significant advances over that time. Four main themes can be discerned: 1) certain radiatively active gases are responsible for warming the planet ; 2) that humans can inadvertently influence this warming; 3) climate models are designed to permit prediction of the climatic changes in the atmospheric loadings of these gases but that they have not yet achieved this goal of prediction; and 4) many scenarios of changes, and especially of impact, are premised on relatively weak analysis. This latter point is illustrated by an examination of the relationship between increasing temperature and sea level change (the oceanic response to atmospheric warming). Current research suggests that sea-level rise is not likely to be as high as had previously been anticipated.