A Noah's Ark of sorts is being built deep inside a mountain on the Norwegian archipelago of Svalbard. There, inside the Arctic Circle and high enough to be 80 meters above sea level even if the poles should totally melt, seed samples of every agricultural crop in the world - some 1.5 million varieties - will be stored to insure biodiversity in case of disaster.
An excellent idea. Something similar should be done with DNA from every form of life, not just crop seeds. In fact, it should be expanded even further, so we have a "backup copy" of all Earth life stored off the planet as well.
Let's expand this even further, with a continuously updated copy of all knowledge, or at least all the knowledge required to rebuild civilization. This is discussed in the book "The Survival Imperative: Using Space To Protect Earth" by William E. Burrows (a member of the Lifeboat Foundation). In it, he proclaims "The most important fact of this century is not that Earth is threatened in many ways. It is that for the first time in all of its history a decisive means of protecting the home planet exists. It is by using space." We have the means, but do we have the will?