It is not all that easy to keep up-to-date charts available. One of the issues is that you really want to have some description with the chart, so that you know what you are looking at.

One approach is to use the little rectangles at the top of the screen that say "Peak Oil Overview", "Peak Oil Update", and "Oilwatch Monthly". If you click on any of those rectangles, you will find a series of articles, with the most recent ones on top. These articles have a lot of graphs in them. The most recent stories are at the top of the screen. Once you have the story open, you can link to a chart by right clicking on the chart, and choosing an appropriate option.

If you know which person is likely to have put together charts of a particular type, another way to find recent charts is to look at the list of stories by the particular author (Click first on the person's name in the personnel list, then click on "stories by"). From the list of stories, one can choose the most recent story that would likely have graphs of the desired type.

Regarding the charts that Roscoe Bartlett used, I found this link to recent presentation he gave, that has many of the same charts as in his Converging Environmental Crises talk.