02 August 2011

The NZ ETS Review 2011 and the Minister's Chartjunk

This evening I was intending to carefully read the Report on the New Zealand Emissions Trading Scheme that Minister for Climate Change Issues Nick Smith released today and write a considered review.

However, I only got as far as Nick Smith's forward on the the third page when I got stopped in my tracks by Figure 3, a misleading piece of chartjunk if I ever saw one, about New Zealand being on target to meet its obligations under the Kyoto Protocol. Here it is.
The chart legend says it shows "Kyoto net emissions (actual emissions)". This parameter trends upward to 2007 and then in 2008 and 2009 it suddenly drops below the blue line of NZ 1990 emissions. Thus showing we are meeting our emissions reduction commitment that we signed up in the Kyoto Protocol. Its enough to make you proud to be a Blue-Green.

This chart is junk because it misrepresents the underlying data on greenhouse gas emissions. Back to the legend: "Kyoto net emissions (actual emissions)". Why does it say "actual emissions" in brackets? Because Smith would like you to think that. Lets look at a real chart of real New Zealand greenhouse gas emissions.

This shows total real emissions up to 2007 and predicted emissions 2008 to 2012 - the green line. It looks nothing like Fig 3. The actual and predicted trend does not show a return to 1990 volumes of emissions. However, that legend also said net emissions, that is total or gross emissions in any year less carbon absorbed by forests. Maybe Fig 3 is based on net emissions.


The trend in net emissions (total less forest sink removals) or the blue line shows an even steeper rate of increase than the total emissions. So how can Fig 3 show that New Zealand reduced emissions to 1990 volumes? Two more clues are in Figure 3. The title is "Kyoto net" and there is a note under the data source says "Kyoto net 2000-2007 values are backcasted". So the Fig 3 data is not just "net", it is also "Kyoto net" and "backcasted". What does ''backcasted" mean? Another chart shows how Smith gets to Fig 3 from the real total and net emissions data.


Greenhouse gas emissions, as defined for compliance with the Kyoto Protocol, are gross from 1990 to 2007, and once the Kyoto commitment period starts in 2008, an Annex B country like New Zealand can meet its target by deducting removal units issued for carbon sinks - so Kyoto-defined emissions go net from 2008. Hence the red line. The removal units issued for afforestation (the increase in carbon stock in a forest planted since 1990) appear as if from nowhere in 2008 and disguise the growth in both the gross and net emissions.

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