You make the mistake of looking at short time intervals which are subject to internal cycles, like El Nino/La Nina. Climate change is about long term trends, not short term swings.  1998 was a particularly hot year because of an usually strong El Nino event. The heat balance of the earth is still increasing since that time, but more of the heat has been going to the oceans than the atmosphere in the last few years. When you take into account the effects of ocean cycles, solar output, and volcanic activity, you see that the earth is indeed still warming. I think the following two graphs will help visualize what I am saying:

source: http://iopscience.iop.org/1748-9326/6/4/044022