This graph shows the gross and net greenhouse gas emissions for New Zealand since 1990. It is from the annual report from the MFE. We’re a long way off the 5% reduction from 1990 levels we have committed to. This is partly because the lack of an international agreement has seen the global price of carbon credits fall, which means the Emissions Trading Scheme doesn’t send much of a price signal to encourage less greenhouse gas use.
Of interest is that gross emissions are at much the same level in 2013 as 2008.
The challenge with policy around greenhouse gases is to reduce greenhouse gas emissions but not reduce economic growth – ie have fewer greenhouse has emissions per unit of GDP. Simply calling for us to get rid of one fifth of our dairy herd is economically suicidal, but also would be worse for the environment as other countries would simply increase their dairy output (and generally they produce more emissions in their dairy farming).