How To Discern Science from Pseudoscience

What do you do when you see a new "scientific story" ? Do you believe it automatically if it suits your political viewpoint? Do you doubt everything, or are you trusting of Ph.D.s, or environmentalists, or your favorite group? How can you tell what is true?

I start in 2 places: Google Scholar for general scientific topics or Pubmed for medical topics.

Here's an example: someone mentioned the detrimental effects of ocean acidification with rising atmospheric carbon dioxide levels at lunch one day. Totally convinced the ocean is set to become an acid-bath dead zone. I went to Google Scholar to check the facts. From most university campuses (and probably the big-city libraries as well), you can access all the major journals. I was surprised by what I found. Several papers came out in 2003 and 2004 on the topic of ocean acidification. Most started with some variation of the following sentence from a paper in Science, one of the top scientific journals in the English language (I am quoting from memory, so this may be a slight paraphrase):

"Due to a paucity of observational data, we are basing the following calculations on computer modeling of known ocean biochemistry and projected CO2 levels." In other words, all the projections are based not on observation (which has shown ocean pH declining by 0.1 from about 8.2 to about 8.1 in the past 100 years (no citation was available, assumed to be common knowledge in the field)), but on computer models. Other papers from the same time period showed that ocean biochemistry far from human habitation is quite different from that close to land, and some admitted that, long term, more CO2 means a more alkaline ocean, not more acidic. Only in the short term would the ocean become more neutral (7 is neutral so it is alkaline right now). Yoicks! Pays to do a little scientific reading in reputable journals rather than accepting lunch-table environmentalism as fact.