When would we use the subjunctive tense in Spanish?

The subjunctive mood does not exist in English, but it does exist in Spanish! It is triggered by expressions of doubt or uncertainty, or a desire to do something. For instance, 'It is important that' implies doubt because we do not yet know what it is that is important. Hence we need the subjunctive to conjugate the next verb after this phrase. For instance, 'It is important that we recognise the negative effects of global warming' would be: 'Es importante que reconozcamos los efectos negativos del calentamiento global'.