GHG emissions must peak by 2015

A new EU report highlights the urgency of reducing emissions of greenhouse gases if a 2°C target is to be met.

Global emissions of greenhouse gases must peak in three to five years and be reduced by three per cent annually thereafter, according to a report¹ recently published by the European Union Presidency, which looks at scientific perspectives on climate one year after the Copenhagen Climate Conference.

The report argues that a peak in emissions by 2015 is required if we are to have a reasonable chance of limiting average global surface warming to 2°C, the ultimate objective of the United Nations Framework Convention on Climate Change. The later the peak, the higher the subsequently required reduction rates become. Peaking after 2015 would likely require more than a three per cent reduction in emissions each year.

The Copenhagen Accord sets a goal of 2°C and calls for parties to the Convention to submit their 2020 emission reduction pledges in order to begin the work towards achieving this goal. Additionally, it allows for a review of a 1.5°C limit in 2015. The EU report does not analyse in detail the reductions needed to reach 1.5°C, a target advocated by more than 100 countries and NGOs. Instead, the report examines the chances of reaching the 2°C target with present climate commitments.

According to the report, the current emission reduction pledges associated with the Copenhagen Accord fall short of the 2020 goals required to provide a reasonable chance of limiting warming to 2°C, without requiring potentially infeasible post-2020 reduction rates. Even the most optimistic interpretation of the current pledges leaves a gap of between two and six gigatonnes of CO₂ equivalent emissions by 2020. Excluding the conditional pledges and other optimistic hypotheses, the gap in 2020 is approximately ten gigatonnes of CO₂ equivalents.

The main conclusions of the report are based on what would be required to provide at least a 66 per cent probability that the temperature increase would be limited to 2°C, and would require global emission reductions of 50 to 70 per cent relative to 1990 levels by 2050.This assumes further emission reductions after 2050. If a higher probability of staying below 2°C is required, then greater emission reductions would be needed. If a lower probability is considered acceptable (for instance, a 50 per cent chance) then emission reductions could also be lower.

However, the analysis of the current Copenhagen Accord pledges shows that, GHG emissions must peak by 2015 even allowing for a lower 50 per cent chance of limiting warming to below 2°C, current commitments would require post-2020 emission reduction rates that may not be feasible.

To ensure at least a 66 per cent chance of limiting global warming to less that 2°C, the EU report suggests:

Reductions of long-lived GHGs, such as carbon dioxide
Complementary measures for shorter lived warming agents
In the longer-term (post 2030), possible deployment of technologies that achieve negative CO₂ emissions.

Cumulative emissions of GHGs are most important. Given the short atmospheric lifetime of some warming agents, temperatures in the longer term will be little affected by mitigation action of these agents in this decade, although mitigation could slow the current rate of warming.

The achievement of the large reductions in anthropogenic GHGs required to meet the 2°C limit is highly dependent upon the implementation of effective policy instruments.

Recent scientific literature reinforces the evidence provided by the IPCC Fourth Assessment Report that limiting warming to less than 2°C considerably reduces the risk of triggering accelerated or irreversible changes in the climate system, as well as large-scale adverse impacts. Nevertheless, significant risks do still remain. Impacts of climate change will, in addition, not be the same everywhere and some regions or sectors might experience a disproportionate amount of adverse impacts.

As mentioned, the EU report also notes that the Copenhagen Accord calls for a review, in 2015, of a potential 1.5°C limit. It concludes that research in relation to this is expected to be synthesised in the upcoming IPCC Fifth Assessment Report. The few limited assessments currently available give preliminary evidence that such a goal might only be possible by allowing temperatures to initially exceed 1.5°C, followed by temperature reductions towards the end of the century or later.

Reinhold Pape

¹. Scientific perspectives after Copenhagen. Information reference document, October 2010.

In this issue

Extra time for non-road vehicles to meet limits

Manufacturers of tractors and engines used in non-road mobile machinery will need more time to meet already adopted stricter emission limits, according to the European Commission.

Air pollution and health in Asia

The World Health Organisation (WHO) estimated in 2002 that over 500,000 deaths in Asia in the year 2000 were caused by outdoor air pollution exposure, accounting for approximately two thirds of the total global burden of deaths attributed to ambient air pollution.

Intercontinental transport of air pollutants

Throughout the northern hemisphere, intercontinental flows of important air pollutants, such as ozone and fine particles, have a significant impact on environmental quality.

Tougher emissions standards for motorcycles

European motorcycles should come with advanced anti-lock braking systems, cleaner engines and daytime headlights in order to reduce road deaths and pollution, according to new emissions and safety requirements for motorcycles and all other L-category vehicles proposed on 4 October by the European Commission.

Coal in Europe - states still support a dying industry

In this series of short articles, some of AirClim's partner organisations provide an insight into the domestic situation of the coal industry in Hungary, Slovakia, Slovenia and Ukraine. Behind each article lies a larger report which can be found online. The articles describe a reality of continued state support for a crumbling crumbling industry that is damaging health, the environment, and national economies.

EU consults on marine fuels

The European Commission is seeking stakeholder input via an internet consultation on a forthcoming proposal to update the EU directive on the sulphur content of marine fuels.

Industrial Emissions Directive adopted

On 8 November the new Industrial Emissions Directive (IED) was formally adopted by the Council of Ministers. It updates and merges seven pieces of existing legislation on solvents, large combustion plants (LCPs), waste incineration, titanium dioxide production and integrated pollution prevention and control (IPPC).

More EU air quality failures

In late November the European Commission decided to take four more member states – Cyprus, Italy, Portugal and Spain – to the European Court of Justice for failing to comply with EU air quality limit values for airborne particles (PM₁₀).

Wind can provide 20% of electricity by 2030

Wind could meet twelve per cent of global power demand by 2020, and up to 22 per cent by 2030, according to a study published by the Global Wind Energy Council and Greenpeace International.

New analysis of national emissions ceilings

Additional measures to achieve the interim targets of the thematic strategy on air pollution would cost less than €3 per person in 2020, or less than one eurocent per day.

MEPs call for a binding energy efficiency target

On 9 November 2010 the European Parliament's Industry, Research and Energy (ITRE) Committee reiterated its call for a binding EU target on energy saving, a demand also made by the Environment Committee in October...