In December this year, representatives of 196 countries will attempt to reach an agreement to reduce greenhouse gas (GHG) emissions with the aim of limiting global temperatures increase to less than 2 degrees. If this Conference of the Parties (COP 21) in Paris is successful it will be the first time, from 2020, that both developed and developing countries will commit to tackling GHG emissions.

Just a week before the Paris Climate Conference, this post takes stock of historic trends in emissions for both developed and less developed countries, details the current rates of emissions (increases and reductions) and examines when the ‘carbon budget’ to stay within 2⁰C of global average warming will likely be exhausted.

With GHG emissions rising, can world leaders take the necessary steps in Paris to reduce emissions to ‘safe’ levels?

Global annual greenhouse gas emissions are increasing, but growth may have stalled in 2014…

Industrialisation processes of the 18th and 19th century saw humans begin to burn fossil fuels at an increasing rate. Annual fossil fuel emissions have more than tripled since the 1960s and the rate of increase has been faster in recent decades.

However, the latest figures for global CO2 emissions in 2014, published on Wednesday 26 November 2015, showed a distinct ‘slowdown’ in the rate of emission growth. An increase of only 0.5% in 2014 is less than the 1.5% in 2013, 0.8% in 2012 and an average of 4% a year over the previous decade.

Global annual GHG emissions from fossil-fuel use and cement production (GtC/yr), 1959-2013
Figure1AclSource: Trends in global CO2 emissions: 2014 Report, House of Commons Library analysis

Much of this increase is attributable to the increasing industrialisation of what are now middle-income countries, in particular China whose emissions have nearly trebled since the turn of the century. At the same time, many developed countries have been able to stabilise their emissions, and in some instances even reduce their emissions.

Annual CO2 emissions from fossil-fuel use and cement production in BRICs countries, 1990-2013

Figure2AclSource: EU EDGAR database, House of Commons Library analysis

The United Nations Framework Convention on Climate Change (UNFCCC)

Historically, it is the developed world where the majority of greenhouse gases have been emitted. In 1992, the United Nations Framework Convention on Climate Change (UNFCCC) was adopted. This treaty placed different obligations on countries at different stages of development. Roughly speaking, the treaty separated the world into two groups.

  • The Annex I Parties: countries classified as industrialised; and
  • The Non-Annex I Parties: mostly low-income, developing countries.
  • The chart below shows that while there is a shrinking proportion of annual emissions coming from the 43 Annex I countries, it was not until 2006, that the aggregate emissions from the 153 Non-Annex 1 countries (which includes China) overtook their developed world counterparts.
Annual global CO2 emissions from fossil-fuel use and cement production Non-annex 1/Annex 1 countries, 1970-2013

Figure3AclSource: EU EDGAR database, House of Commons Library analysis

How successful have Annex-I countries been at reducing their emissions?

The objective of the UNFCCC treaty, set out in article 2 of the Convention, is to “stabilize greenhouse gas concentrations in the atmosphere at a level that would prevent dangerous anthropogenic interference with the climate system.”

Since the treaty was signed in 1992, annual global GHG emissions have increased from around 22 GtCO2 a year to more than 35 GtCO2. However, during that same period emissions from Annex-I countries have remained more or less constant at around 14 GtCO2.

Aggregate global annual CO2 emissions from fossil-fuel use and cement production Non-annex 1/annex 1 countries, 1992-2013

Figure4AclSource: EU EDGAR database, House of Commons Library analysis

Since 1992, Annex-1 countries have, on the whole, managed to stabilise their annual emissions. Indeed, the direction of travel for emissions in the most developed countries are down (except for the US, which has seen a small rise in annual emissions). At the same time, India and China’s emissions have more than doubled. This reflects both their industrialisation and economic development since 1992. But also as many argue that emissions from manufacturing and industry has to a large extent been exported from the developed world to emerging and middle income countries. The following chart compares the 2013 emissions of the 6 biggest emitters in 2013 (and the UK) with their 1992 emissions before the UNFCCC was signed.

Annual CO2 emissions from fossil-fuel use and cement production in 1992 and 2013 for the Top 6 emitters (and the UK) in 2013

Figure5AclSource: EU EDGAR database, House of Commons Library analysis

The European Union (EU) has been at the forefront of negotiations to reduce greenhouse gas emissions. The EU-28 countries have reduced their total annual emissions by around 10% since 1992. In 1992, the EU-28 was responsible for 4.1 GtCO2 which had been reduced to 3.7GtCO2 in 2013, and reduced its contribution to global emissions from 18% to 10.5%.

Per capita emissions

Considering total national emissions alone does not provide the whole picture, as countries with larger populations are likely to have higher emissions. Another way, and many argue a more equitable way, to think about the relative contributions to global emissions, is on a per capita basis. In 2013, for example, the Chinese per capita CO2 level of 7.4 tonnes exceeded the mean EU28 level of 7.3 tonnes, but remained still under half the US level of 16.6 tonnes. India’s per capita emissions were still very low, 1.7 tonnes, despite also being one of the major global emitters.

CO2/capita emissions, 1990–2013 (tonnes CO2 per person) selected countries
Figure6AclSource: Trends in global CO2 emissions; 2014 Report, House of Commons Library analysis

The ‘carbon budget’ and cumulative emissions

Dangerous anthropogenic interference with the climate system for some time now been broadly defined as a global average temperature increase of above 2⁰C. The IPCC fifth assessment report estimated that having a likely or 66% chance of limiting global temperature increases to 2oC would require total emissions from human sources to be limited to 1000Gt CO2 from 2011. The chart below details different projected ‘emissions pathways’ between now and 2100 and the associated temperature increases. In 2013 global emissions were 39.3Gt CO2. This means that the 1000Gt budget would be used up in 21 years, by 2036, if emissions continue unabated at current levels.

Figure7AclSource: IPCC, Climate Change 2013: The Physical Science Basis. Figure SPM.10 – Global mean surface temperature increase as a function of cumulative total global CO2 emissions.

As a consequence of these emissions, atmospheric concentrations of CO2 first crossed the 400 ppm threshold in 2013, some 120ppm higher than in the pre-industrial period (before 1850). Increased atmospheric CO2 concentrations result in higher global average temperatures, and earlier this month, the UK Met Office announced that global average temperatures, for the period January to September 2015, were more than one degree above pre-industrial levels. The first time that this threshold has been breached.

When will emissions peak?

The Committee on Climate Change has previously stated that in order for global average temperatures to not rise above 2⁰C, global emissions should peak by 2020 and be halved (or more) by 2050. On the cusp of the Paris Climate Conference, hopes have been raised that peak emissions may now be in sight with a slowdown in global emissions in 2014. Global emissions growth slowed in 2014 to just 0.5%, following growth of just 0.8% in 2012, 1.5% in 2013 and an average of 4% a year over the previous decade.

CO2 emissions from fossil-fuel use and cement production in the top 5 emitting countries and the EU
Figure8AclSource: Olivier JGJ et al. (2015), Trends in global CO2 emissions; 2015 Report: Figure 2.2.

The report’s authors primarily attribute this slowdown to a lack of growth in Chinese coal use. Indeed, for the two biggest emitters (China and the US) emissions in 2014 increased by only 0.9% and the European Union’s emissions dropped by an unprecedented 5.4%. However increases in other countries continue. For example India’s emissions, rose by 7.8% between 2013 and 2014.

Authors: David Hirst and Elena Ares