Click here to install the certificate
You will then see a box like this.

Ensure you check the box Trust this CA to identify web sites.
Then click OK
Apple users (Chrome and Safari)
Click here to download the certificate
It will download in either browser
Open your Keychain Access application, it can be found in Applications -> Utilities.

Click File, then Import items...
Using the file browser go to your Downloads folder and choose the ipCAGlobal.crt file. Then click Open.
This will install the certificate and you can close Keychain Access.