New Zealand greenhouse gas trends also up
Science Centres: Atmosphere
The World Meteorological Organization (WMO) has announced that the main greenhouse gases have reached their highest levels recorded since pre-industrial times (before 1750). According to the WMO, in 2009 there was 38% more carbon dioxide in the atmosphere than pre-industrial; methane was 158% higher, and nitrous oxide 19% more. Data from New Zealand contributes to this global picture.
NIWA started monitoring greenhouse gases in the early 1970s. The measurements are taken at Baring Head near Wellington, including the longest continuous in situ record of atmospheric carbon dioxide in the Southern Hemisphere. The air sampled is broadly representative of greenhouse gas concentrations in the Southern Hemisphere (which are less than global averages). Overall, these show upwards trends.
Carbon Dioxide (CO2)
Measurements of carbon dioxide at Baring Head began in the early 1970s, and have increased ever since. This is consistent with global trends: the carbon dioxide concentration has risen steadily ever since to a global average in 2009 of 386.8 parts per million.
Methane (CH4)
Baring Head measurements of methane began 1989–1990. The methane concentration rose until the early 2000s, then stabilised for several years before resuming an upwards trend in about 2007. The 2009 global average was 1803 parts per billion.
Nitrous Oxide (N2O)
NIWA began measuring nitrous oxide at Baring Head in mid-1996. That concentration is also steadily increasing over the long-term, climbing to a global average 322.5 parts per billion in 2009.
For comment, contact:
Dr Mike Harvey
Principal Scientist
Atmospheric Emissions Group, NIWA
Tel: +64-4-386 0308
Mob: 021 175 6516
More resources:
WMO Statement
New Zealand data used by the WMO
Watch Dr Katja Riedel from NIWA explain the process of sampling air at Baring Head