Gases that contribute to the greenhouse effect include: 1  Water vapor. 2  Carbon dioxide (CO 2). 3  Methane. 4  Nitrous oxide. 5  Chlorofluorocarbons (CFCs).
You can start maternity leave any time from 11 weeks before the beginning of the week your baby's due. You can bring the date forward if you need to take time off work for pregnancy-related reasons within four weeks of the expected birth date. Your employer may make you start your leave from then.
How do I qualify for maternity leave? Here's where maternity leave gets tricky: In order to actually qualify for maternity leave, you must have worked at least 12 months with your current company. If you're a part-time employee, the requirement is a minimum of 1,250 hours in the past year.