Greenhouse gas emissions growing but limiting warming remains possible
STRICTLY EMBARGOED TO 9pm, 13 April, NZ time
On Sunday in Berlin the Intergovernmental Panel on Climate Change (IPCC) released a further climate change assessment
report. This “Fifth Assessment Working Group 3 report” documents recent trends in greenhouse gas emissions and
identifies their sources. It assesses options for reducing emissions of these gases in order to limit future human-
induced changes in climate.
The report shows that global greenhouse gas emissions have continued to grow – on average at 2.2% per year between 2000
and 2010. Carbon dioxide remains the major long-lived greenhouse gas emitted as a result of human activities. Economic
growth and population growth are the two main drivers of recent increases in global carbon dioxide emissions from fossil
fuel combustion. They outpaced gains from producing and using energy more efficiently.
The report considers a wide range of potential scenarios for future greenhouse gas emissions, and concludes that
scenarios that limit CO2-equivalent concentrations in 2100 to about 450 parts per million are likely to keep global
temperature change below 2°C. It says such scenarios include substantial cuts in anthropogenic greenhouse gas emissions
by mid-century. (Countries that have ratified the United Nations Framework Convention on ClimateChanges (UNFCCC) have
agreed to a long-term goal of keeping global temperature increases below 2°C compared to pre-industrial times).
The report says that without additional efforts to reduce greenhouse gas emissions,emissions growth is expected to
persist. But it also identifies and assesses measures and technologies that could assist with reducing emissions.
Potential improvements are available through low-carbon energy generation, more energy-efficient transport, buildings
and industry, reduced deforestation, bioenergy, better management of cropland and grazing land, and urban planning
affecting infrastructure, land use and transport choices.
Dr David Wratt of the NZ Climate Change Centre and NIWA has attended the plenary meetings of all three IPCC Working
Groups. He says: “The first two reports of the IPCC Fifth Assessment confirm that climate change poses major problems.
This third report shows that our actions to date are not enough to put us on a global track for limiting warming to 2
degrees. But the report also provides options for reducing emissions – and shows that if we make sufficient reductions
we can escape some of the more serious impacts that would result from unconstrained climate change”.
Full text of the “Summary for Policymakers” of the IPCC Working Group 3 Report will be available on the IPCC website (www.ipcc.ch). Three New Zealand experts contributed substantially to the report: Professor Ralph Sims of Massey University as a
Convening Lead Author of the chapter on Transport, Dr Harry Clark Director of the New Zealand Agricultural Greenhouse
Gas Research Centre as a Lead Author of the chapter on Agriculture, Forestry and Other Land Uses, and Dr AdamJaffe
Director of Motu Economic & Public Policy Research as a Lead Author of the chapter on National and Sub-National Policies.ext of the “Summary for
Policymakers” of the IPCC Working Group 3 Report will be available on the IPCC website (www.ipcc.ch). Three New Zealand experts contributed substantially to the report: Professor Ralph Sims of Massey University as a
Convening Lead Author of the chapter on Transport, Dr Harry Clark Director of the New Zealand Agricultural Greenhouse
Gas Research Centre as a Lead Author of the chapter on Agriculture, Forestry and Other Land Uses, and Dr AdamJaffe
Director of Motu Economic & Public Policy Research as a Lead Author of the chapter on National and Sub-National Policies.