Quite a few space missions (some of which are mentioned in the article) depend on this technology. It's useful in situations where solar isn't effective (eg the outer planets)

The article, while informative, is somewhat outdated as it was published in 2012.

Because the relationship between heat gradients and electricity is an important part of space travel. There are no doubt countless situations where one might make use of this either to heat/cool or generate power via RTGs.

Since everything NASA do can be used to observe global climate change, what does the NASA Global Climate Change group do?