Google started a partnership program with Simba for providing JDBC drivers for Google Big Query. The driver can be downloaded from https://cloud.google.com/bigquery/partners/simba-drivers/. The zip contains also a PDF documentation about how to connect. Also check http://www.simba.com/drivers/bigquery-odbc-jdbc/ for driver details.
In the connection dialog review the connection URI in the advanced tab. If using the Google Authentication, a dialog will pop-up asking for a token.
Copy-paste the text from the text field into a web browser. Google will ask if you accept connections and will return a token. Paste this token back in the text field.
Unfortunately we didn't succeed a complete test with Google Big Query. We got to the point where we should generate the p12 file and connect using it. Here we didn't found the right documentation to generate it. If you succeed to generate the p12 file please let us know, we will continue our integration.