Where do our Greenhouse Gases go?

Although we are still producing increasing volumes of greenhouse gases, it appears that the Earths natural carbon sinks are not yet at capacity.
Earths natural ecosystems absorbing Greenhouse Gases

How long can this go on for?
Is it an excuse to continue to produce more greenhouse gases?
Is the problem with the Earths ability to absorb greenhouse gases or the amount of gases produced by Human activity?

Northwest Earthquake Risk in U.S. Looms Large

The US has been 'waiting' for a big Earthquake to strike for some time, Scientists in the states now think it may strike in the next 50years.
Large US quake looms