Hi, Ed,
Unfortunately there is not a way to increase the font size on this site in particular apart from zooming in, but you can change the minimum font size on all sites you visit, just once, and that should make this site and others easier to read. You can also change the default fonts used, in case that would improve legibility as well.
The exact sequence varies by browser, but in Chrome, for example, you would select Preferences/Font Size to change the default size, and Customize Fonts to change the fonts used. Let me know if you have difficulty with whatever browser you use.
Best,
Laurie