scales
Yes, scale can make graphs look more impressive - or less so. In et's graph, there was a rise of about 60 ppm over a period of approximately 200 years, in terms of a slope about 300 ppm per 1000 years. On one of the steeper parts of Tom's graph (about 10000 - 15000 years ago) the rise was about 70 ppm - but over a period of about 5000 years, or 14 ppm per 1000 years.