OK, it's better if you go to the source, where you can actually read the text, and you can click on each bubble for more information.
It really is impossible to read here, so I'll tell you what it says. The horizontal axis is the effect on Energy Security (to the right means increased security, to the left means decreased security). The vertical axis is effect on the climate (up means a positive effect, down means a negative effect). The size of the bubble is the size of the effect. See the big bubble at the far right, and at the top? That says that if we increase CAFE standards, it will have BIG, POSITIVE effect on both energy security and climate.
If you want to compare all the different energy solutions being considered, and how they relate to energy security and climate change, this is a great summary. Check it out for yourself.
This was put together by World Resources Institute, a well respected "environmental think tank that goes beyond research to find practical ways to protect the earth and improve people's lives" (in their own words).