Sunday, August 2, 2009

How Hard Would Dramatic Greenhouse Gas Emissions Reductions Really Be?

As the New Zealand Government consults on a greenhouse emissions reduction target for New Zealand we are often treated to a talking point along the lines that a 40% reduction at 2020 is "obviously" not feasible. This is always coupled with pointing out that 40% means a 40% reduction on 1990 emissions and that's a 60% reduction on today, and yes Labour was in power for much of the intervening period and what a debacle that was and so on and so forth.

Here's Kiwiblog's latest on the subject for example, and Matthew Hooton gave stirring rendition on Nine to Noon on National Radio during last week.

I had some sympathy for this view, and certainly if DPF or I, neither of us with any relevant qualifications, spend a few seconds perusing New Zealand's emissions profile, it does seem a pretty tall order to reduce greenhouse gas emissions by 60% over a decade.

Allow me to point to a remarkable recent Australasian efficiency achievement as a corrective to this pessimistic view.

Many of you will know that south-east Queensland has just emerged from a prolonged drought. At its lowest point the dams that store Brisbane's drinking water were at just 17% of capacity. As a result the Queensland Government initiated a series of water restrictions and water efficiency campaigns.

Prior to the drought per capita daily water consumption in south-east Queensland was pushing 300L. Three years later at end of the drought it was down around 130L.

That's right, domestic water consumption in south-east Queensland was reduced by more than 50% in just three years! Look at the figure, from the official report here. (Click on the figure to read it clearly.)

And what is residential water consumption in south east Queensland today, roughly a year after the end of the drought? 140L per person per day. 120L if it's school holidays.

This goes to show that dramatic and permanent efficiency gains are possible if there is the public and political will to make them. You really have to ask yourself if it is that much harder to reduce our dependence on greenhouse gas emissions than it is to reduce water use? (There are some obvious possibilities but that's for another post.)

I've said it before and I'll say it again, efficiency gains are the first and cheapest way to make reductions in greenhouse gas emissions. And the sooner big business stops paying lobbyists to derail change and starts paying engineers to work out how to solve the problem, the better.

The ideas in this post are shamelessly stolen from a recent lecture by Professor Juerg Keller. The line about engineers is likewise stolen from US Secretary of Energy and Physics Nobellist Steven Chu.