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Carbon Brief Staff

Carbon Brief Staff

07.06.2011 | 11:00am
ScienceLatest emission figures show world on track for 4 degrees
SCIENCE | June 7. 2011. 11:00
Latest emission figures show world on track for 4 degrees

Figures released by the International Energy Agency (IEA) last week showed that carbon emissions from energy production reached a record high in 2010.

At 30.6 Gigatonnes, emissions were 5% higher than the previous record year in 2008.

Dr. Fatih Birol, the chief economist of IEA called the latest data “another wake-up call” while Lord Stern warned that “the room for manoeuvre is narrow and the window of opportunity is closing” for emissions cuts.

The IEA figures were particularly significant because emissions had been expected to fall as a result of the economic downturn. As a result of the recession, emissions fell in the UK and globally during 2009, leading some to suggest that the world had been given “breathing space” to start a shift to low-carbon infrastructure. The resurgence of carbon emissions makes it clear that this hasn’t happened.

Australian blog Skeptical Science has now produced the following graph comparing current global emissions with the IPCC ’emissions scenarios’, which speculate about future emissions and likely temperature changes that may result.

CO2_Emissions _IPCC_1024

Figure 1: US Energy Information Administration (EIA) global human CO2 annual emissions from fossil fuels estimates vs. IPCC SRES scenario projections.  The IPCC Scenarios are based on observed CO2 emissions until 2000, at which point the projections take effect. For actual emissions, figures up to 2008 are taken from the EIA. 2009 emissions are 29Gt, 2010 emissions are 30.6Gt – figures taken from the IEA.

The creators of the graph suggest that the best fit for our behaviour in the real world is currently IPCC Scenario A2, which describes a world where there is:

* Delayed development of renewable energy.

* Relatively slow change in current birth and death rates.

* Relatively slow reduction of inequality.

* Relatively slow improvement in energy efficiency.

* No barriers to the use of nuclear energy.

Scenario A2 gives a most likely global temperature rise of around 3.5°C by 2100 above temperatures in 2000 – more than 4°C above pre-industrial levels. See the second (red highlighted) grey bar from the right in the graph below.


Figure -spm -5-l

Figure 2: IPCC 2007 Working Group 1, Figure SPM 5

If the prospect of a four-degree rise in temperatures by the end of the century on current trends wasn’t alarming enough, the IEA calculated that 80 percent of projected 2020 emissions from the power sector are already ‘locked in’ by infrastructure already being built or has been given the go-ahead.

This means that emissions may well continue to accelerate – with global emissions continuing to rise towards – or beyond – the IPCC’s most pessimistic A1FI or “fossil-fuel intensive” projection.

Scenario planning gives a broad-brush picture of what future temperature rise will be. Scientists needs more than a few years data to draw conclusions about where we are going, so we don’t know exactly where we are going. But with the fall in emissions over the last couple of years occurring as an accident of global economic turmoil rather than because of infrastructure change, it’s the higher emissions scenarios that remain the most relevant for mapping our future.

Ironically, relatively little research has been done on the likely consequences of these higher-end scenarios – because scientists assumed that the world would take action to reduce emissions. Met Office scientist Richard Betts however estimated in a paper published in later 2010 that the A1FI scenario could lead to a temperature rise of 4 degrees in just fifty years time (2060-70).

There is no doubt that the impacts of four degrees of temperature rise would be incredibly serious for the environment and for human society. One recent paper concluded that:

“In such a 4°C world, the limits for human adaptation are likely to be exceeded in many parts of the world, while the limits for adaptation for natural systems would largely be exceeded throughout the world. Hence, the ecosystem services upon which human livelihoods depend would not be preserved.”

The disconnection of climate skeptics from the realities of the debate were thrown into contrast during the debate around the IEA publication. Dr Benny Peiser, director of the Global Warming Policy Foundation argued on Radio 4 that:

“â?¦ no-one really knows what the trajectory will be within the next 100 years, whether the warming trend will be pronounced, whether it will be moderate, whether it will be smaller, no-one knows…”

Whilst may not know precisely what trajectory we are on, but it is inaccurate – and irresponsible – to suggest that we don’t have ballpark figures for what will happen if global emissions aren’t curbed. We do – and the news isn’t good.

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