There have been calls for smaller carriers before, but the large size of jet aircraft created a strong case for large (90-100,000 ton) carriers. That trend, however, is now going into reverse. The next generation of aircraft will include the vertical take-off version of the F-35, the 25 ton F-35B, and several, smaller, UAV designs. The carrier based UAVs are no fantasy. Work on flight control software for carrier operations is well underway. Combat UAVs (UCAVs) weight about 20 percent less than manned aircraft, and cost 20-30 percent less. They use less fuel as well.
While the navy would prefer to design and build the first generation UCAVs for use on existing carriers, these smaller and cheaper aircraft go together well with smaller and cheaper carriers. That's because UCAVs mean you can get more aircraft on a carrier, and that creates a traffic jam type situation. Moreover, the widespread use of smart bombs means you need fewer bombers over the target. A 50-60,000 ton carrier, with three dozen F-35Bs, UCAVs, UAVs and support aircraft, can be as effective as a Nimitz with 70 F-18s and support aircraft.
In the United States, key legislators are joining in the growing call for smaller, cheaper carriers, and the use of armed UAVs sooner, rather than later. This debate is hot right now because design work is currently underway for the next generation of American carriers. The first ship of new CVN 21 class , is expected to cost nearly $14 billion. About 40 percent of that is for designing the first ship of the class, so the actual cost of first ship (CVN 21) itself will be some $9 billion. Against this, the navy expects to reduce the carriers lifetime operating expenses by several billion dollars because of greatly reduced crew size. Compared to the current Nimitz class carriers (which cost over $5 billion each to built), the CVN 21s will feel, well, kind of empty. Lots more automation, computer networking and robots. CVN 21 doesn't start building until 2008, and won't go to sea until about 2014. By that time, many of the warplanes operating off the carrier will be robotic. By 2014, even more of the crew will be replaced by robots. The CVN 21 will be about the same size as current carriers, but will about half as many sailors on board. The last of the current Nimitz class carriers entered service three years ago.