New Aussie state of the climate snapshot: NZ needs one too

By Gareth Renowden 17/03/2010

Australia’s CSIRO and Bureau of Meteorology have released a State of the Climate report [PDF], a succinct six page effort designed to provide the Aussie public with an overview of how their climate has been changing, and how it is expected to change in the future. Headlines (from the media release):

  • Highly variable rainfall across the country, with substantial increases in rainfall in northern and central parts of Australia, as well as significant decreases across much of southern and eastern Australia.
  • Rapidly rising sea levels from 1993 to 2009, with levels around Australia rising, between 1.5cm and 3cm per decade in Australia’s south and east and between 7cm and 9cm in the country’s north
  • About half of the observed reduction in winter rainfall in south-west Western Australia can be explained by higher greenhouse gas levels.

The news about temperature isn’t good either. All of the continent has warmed over the last 50 years, but some regions have warmed at up to 0.4ºC per decade during that time (see the dark red blobs on the map above) and have seen warming of 1.5 — 2ºC. By 2030 the average temperature is expected to have increased by a further 0.6 — 1.5ºC, and decreases in rainfall will continue in the south, south-east and southwest. The graphics are particularly good — and very telling.

I’m not aware of any similar recent overview for New Zealand, and with the usual suspects doing their level best to promote uncertainty and inaction at the moment, it would be helpful if the local climate science community could cooperate on producing such a clear statement of current evidence and future change. NIWA’s last set of projections for NZ were released in 2008, and are summarised on this informative but rather dense web page. I had a go at bringing the details to a wider public, via articles in NZ Geographic (not my knees, by the way) and Good magazine, but apart from press coverage when the projections were launched, there’s not been much since. I doubt many people will seek out Climate Change Effects and Impacts Assessment: A Guidance Manual for Local Government in New Zealand, 2nd Edition (Ministry for the Environment 2008) for an easy introduction to the subject…