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.
You are entitled to take up to 52 weeks of maternity leave following the birth of your baby. The maternity leave is split into two periods and different rules apply to return to work in either of those periods. The first 26 weeks of maternity leave is known as Ordinary Maternity Leave.