The New Zealand Institute
| Grade | NZ Rank | Trend | Latest Value | 2015 Target | |
|---|---|---|---|---|---|
| D | Not applicable | Bad | 392 ppm | 395 | Steady growth in CO2 concentration |
Without carbon dioxide (CO2) in the atmosphere the Earth’s surface would be very cold. CO2 traps heat in the atmosphere. More CO2 means more trapped heat. In the last ice age the atmosphere was approximately 180 parts per million (ppm) CO2. Around 1800 it had risen to 280 ppm. Now it is 392 ppm and increasing by more than 2 ppm each year.
CO2 is by far the most important of several greenhouse gases emitted as a result of human activity and contributing to atmospheric warming. The measure includes CO2 only for simplicity and because data is readily available and timely.
The Earth’s temperature has increased by around 0.8 degrees Celsius since 1800, generally regarded as the beginning of the industrial revolution. Temperature takes some time to respond to increases in greenhouse gas concentrations but it is estimated that the current concentration of CO2 commits the Earth to another 0.6 degrees of warming, meaning that if the increase in CO2 (and other greenhouse gas) concentration is held constant at today’s 392 ppm then the average global temperature will still rise to 1.4 degrees Celsius above the 1800 baseline.
The effects of modest increases of greenhouse gases on the Earth’s climate are assessed regularly by the International Panel on Climate Change (IPCC). With lower temperature increases, of 1 to 2 degrees Celsius, gradual and moderate climate change is expected to increase the incidence of storms, floods and droughts. There will be increased pressure on food supply, especially in developing countries, and sea level rises will threaten coastal settlements and coastal plains.
However, if higher temperature increases occur there is an increased risk that positive feedback effects will accelerate the warming, potentially triggering abrupt climate change. The world’s scientific community, working with policymakers, has agreed to target avoiding temperature increases of more than 2 degrees to avoid an unacceptable risk of abrupt climate change.
There is uncertainty about how much increase in concentrations would result in an increase of 2 degrees Celsius. Credible estimates range from 350 to 450 ppm indicating that we are already in the danger zone.
Abrupt climate change would be disastrous for New Zealand, along with the rest of the world. Climate change would probably not be gradual and stable; climate chaos is more likely if temperature increases are well above 2 degrees Celsius.
The importance of limiting climate change is widely acknowledged in New Zealand.
Despite widespread consensus among scientists and governments, some people are sceptical about these conclusions and put forward counter-arguments. Useful resources for assessing conclusions and counter-arguments include http://www.realclimate.org and http://www.skepticalscience.com. The government’s website on climate change is a valuable resource too: http://www.climatechange.govt.nz.
As a small country New Zealand cannot have much direct effect on the atmosphere. CO2 concentration is included as a measure because climate will have important direct and indirect effects on New Zealand.
For CO2 concentration it is the world’s performance that matters for New Zealand.
Figure 1 shows CO2 concentration in the world’s atmosphere since 1990. Over the last decade, concentration has increased by an average of 2.0 ppm each year, and in the year to 2011 it increased by 2.3 ppm.
Figure 2 shows annual CO2 emissions by country. China emits more than any other country, followed by the USA, the EU, India, Japan and Iran.
Figure 3 shows that global emissions continue to rise because the developing nations are increasing emissions at a rate that more than offsets reductions from the developed nations. The recent decreases in developed country emissions are largely due to recession rather than behaviour change, so they may not be sustainable. The world’s emission reduction efforts are nowhere near sufficient yet to offset increases due to population and industrialisation.
New Zealand directly contributes less than 0.2% of global GHG emissions. But the world is made up of many populations of 4.4 million people and New Zealand’s 4.4m people are responsible for more emissions than almost all other groups of 4.4 million people in the world. New Zealand’s effort to reduce its own emissions is further covered in the measure CO2e emissions per capita.
Reducing emissions is important to avoid climate and economic risk. But reducing emissions is costly. All countries would benefit from any one country’s emission reduction efforts so each country prefers to have the other countries reduce their emissions so it can gain the benefits of risk reduction without paying the cost.
In response countries have attempted to form an agreement among them all so that each will contribute to the costs of emission reduction. However, so far, the world’s countries have been unable to form an agreement, with talks collapsing in Copenhagen in 2009 and no material progress since.
Efforts to form a binding multilateral agreement continue and the outcome remains uncertain.
Meanwhile in the absence of a multilateral agreement, countries, cities, industries, businesses, non-government organisations and individuals are making their own efforts to reduce emissions. In general those efforts involve changes where the emission reduction results in an economic benefit or modest changes that have small costs.
The aggregate size of these efforts has not been sufficient to slow the growth of CO2 concentrations. While going after the opportunities where emissions reduction is not costly is very worthwhile, it will not be enough to limit temperature rise to less than 2 degrees Celsius.
The Kyoto Protocol was an agreement formed in the late 1990s among the developed nations to slow the growth of emissions. The agreement covered the period from 2008 to 2012 and was intended to be followed by a replacement agreement.
New Zealand is an active participant in international efforts to limit climate change. It was a participant in the Kyoto agreement. In accord with that agreement it measures and reports emissions. It has launched an emission trading scheme (ETS) that provides a framework and tool for management of the levels of emissions.
New Zealand has also committed to a 10-20% reduction relative to 1990 levels by 2020, and declared the intention to halve emissions by 2050. These commitments will be difficult to achieve with current plans. See further commentary in the measure of CO2 emission reductions.
There is still a great deal of uncertainty about how much reduction will be needed to avoid the ‘unacceptable risk’ of abrupt climate change. United Nations and scientific estimates indicate emission reductions of 25% to 40% by 2020 and 80% by 2050 are needed. For long term planning purposes New Zealand should expect both more vigorous efforts to reduce emissions and a need to adapt to the effects of climate change.
Figure 4 shows that agricultural emissions make up 47% of New Zealand’s total emissions, but only 8% for OECD countries. The research investment made by developed countries is not likely to be focused on agriculture; the OECD countries are more likely to prioritise low carbon options in energy, which is 76% of their total emissions.
New Zealand is targeting a leadership position in research to reduce agricultural emissions. Investment in agricultural emission reduction technologies can help New Zealand reduce its annual emissions, be applied abroad to reduce emissions and create revenue from the sale of new technologies and services.
The Government established the New Zealand Agricultural Greenhouse Gas Research Centre in March 2010 to find ways for New Zealand to meet its international greenhouse gas emission obligations without reducing agricultural output. The Centre is working closely with the Global Research Alliance on Agricultural Greenhouse Gases. New Zealand is a leading country in the 32 member Global Research Alliance, chairing its Council, hosting its Secretariat, and co-chairing its Livestock Research Group (with the Netherlands).
New Zealand is also an active participant in climate change research and negotiations, playing its role as a global citizen working with other countries to identify solutions and form agreements.
Effort has begun, both in New Zealand and internationally, to reduce greenhouse gas emissions.
However, our measures emphasise outcomes not intentions or effort and the outcomes are poor. The accelerating increase of CO2 concentrations presents a huge threat. The grade would be an E, except effort is beginning and the risk is now being taken seriously so the grade is a D.
The target of 395 was established in March 2010 based on restricting annual growth to an average of 1.6 ppm until 2015. At the time the target was set, it represented about a 20% improvement on the annual growth for the preceding decade. However, recent years have seen increasing growth rates, not reductions, and the 2011 annual value increase was 2.3 ppm.
To meet the target now, increases will have to be held to a little over 1 ppm per year. Momentum and insufficient effort mean that is already an almost impossible target to meet. Achieving the target would still expose the world to risk of an increase of more than 2 degrees Celcius in global average temperature and so too the risk of substantial and abrupt climate change.
Estimating and summarising emissions of greenhouse gases and the effects can be very complex. There are several gases which create the greenhouse effect; some have more of an effect than others and some remain in the atmosphere much longer than others. You can read more about the science of the greenhouse effect and the relative impact of the various gases at the New Zealand Government website http://www.climatechange.govt.nz/ or follow links to further sources from the ‘start here’ page at http://www.realclimate.org. To simplify the discussion, the effect of different gases is often translated into the equivalent amount of carbon dioxide that would result in a similar effect on the atmosphere. Carbon dioxide is the most common of the greenhouse gases, in terms of volume emitted by mankind’s activities.
Measuring and accounting for these various gases is also very complex, as some activities are included and others excluded for various reasons from a nation’s account. Also, some activities or changes in condition lead to the release or storage of greenhouse gases, such as through growing trees or melting permafrost, and some are included in national accounts and others are excluded. The discussion here focuses on only the primary greenhouse gas, CO2, specifically for Figures 1 to 3 (but not 4). That differs from the data used in the discussion about greenhouse gas emissions, which uses the more complete but less rapidly compiled data on total greenhouse gas emissions, CO2e. More details about definitions of emissions terms for measurement purposes can be found on the UNFCCC website http://unfccc.int/methods_and_science/items/2722.php.
Data on CO2 concentration in the atmosphere is updated monthly from the National Oceanic and Atmospheric Administration’s Mauna Loa Observatory in Hawaii. There is a regular seasonal variation.
There are vocal segments of the population which question climate change theory and evidence. In the documentary film The Great Global Warming Swindle scientists, economists, writers, politicians and others dispute the scientific evidence for man-made global warming and assert that the consensus opinion has been influenced by funding and political factors. Skeptical Science is an effective resource to help you assess the merits of arguments on the topic, relying on peer-reviewed research but summarising the science in concise, approachable plain English. The URL is http://www.skepticalscience.com/ and it has some useful phone apps to ensure you have ready access to data whenever you are engaged in a discussion on climate change.
For more New Zealand specific information see a blog you can find at http://hot-topic.co.nz/.
Figure 1: National Oceanic and Atmospheric Administration (2011). Atmospheric CO2, retrieved 29 August 2011 from http://co2now.org/Current-CO2/CO2-Now/noaa-mauna-loa-co2-data.html.
Figure 2: Data is reported as million metric tonnes. Netherlands Environmental Assessment Agency (2010). No growth in total global CO2 emissions in 2009, Table 3.1, retrieved 2 August 2011 from http://www.rivm.nl/bibliotheek/rapporten/500212001.pdf.
Figure 3: Data is reported as billion metric tonnes. As for Figure 2, Table A1.1.
Figure 4: United Nations Framework Convention on Climate Change (2011). Summary Reports for CO2 Equivalent Emissions, retrieved 15 April 2011 from http://unfccc.int/ghg_data/ghg_data_unfccc/ghg_profiles/items/4625.php; World Resources Institute (2009). World Greenhouse Gas Emissions: 2005, retrieved 2 August 2011 from http://www.wri.org/chart/world-greenhouse-gas-emissions-2005.
Data excludes greenhouse gas emissions from land use change.
For the OECD 29 countries are included with Canada, Chile, Israel, Mexico and South Korea excluded.
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