Four countries and many corporations are now pledging to go carbon neutral. New Zealand, host for World Environment Day 2008, plans to be the first to create a completely carbon neutral economy. Their target is 2020 and they have ambitious plans to radically reduce greenhouse gas emissions with a big increase in renewable power generation and a switch to sustainable transport like electric cars. But half of New Zealand's greenhouse gas emissions come from their huge agricultural sector – from sheep and cows. So how will they manage? And what does carbon neutrality really mean? Earth Report finds out in a special edition marking World Environment Day. 'Blue Sky Dreaming' will be broadcast on BBC World from Friday 6 June - at the following times: (all GMT)

Friday 6 June: 19:30
Saturday 7 June: 04:30
Monday 9 June: 09:30
Tuesday 10 June: 15:30
Wednesday 11 June: 01:30 and 07:30
For broadcast times in your country please check BBC World News Schedules

More on this week's Earth Report