In the most comprehensive report on climate change the UN IPCC has said that the impacts of global warming are likely to be "severe, pervasive and irreversible". Dr Saleemul Huq, a convening lead author said: "Before this we thought we knew this was happening, but now we have overwhelming evidence that it is happening and it is real."
Philip Pearson at the TUC has picked out some of the key energy points at the Touchstone blog and highlights four points on which there is high scientific confidence:
- Global greenhouse gas emissions are accelerating. Despite greater investment in low carbon technologies, emissions grew by one billion tonnes a year (ie a gigatonne) in the past decade, reaching 49 gigatonnes in 2010. This compares with 400 million tonnes a year in the period 1970-2010.
- Carbon dioxide (CO2) from burning fossil fuels and industrial processes made up three quarters (78%) of the increase in greenhouse gases. Most of this is CO2, methane and Nitrous Oxide.
- By 2100, without additional effort, global average temperatures will increase by between 3.7 and 4.8 degrees C. One driver is the albedo effect, the amount of incoming radiation reflected back from the earth’s surface, which falls as the amount of sea ice decreases.
- In futures where we take deliberate action to stem man made global warming to below 2 degrees C above pre-industrial levels, atmospheric concentration of CO2 are “likely” to be 450 parts per million. We are now at 399.5 (March 2014).
The IPCC report also covers the economic impact of taking action on climate change. Diverting investment from fossil fuels into renewable energy and cutting energy waste would shave just 0.06% off expected annual economic growth rates of 1.3%-3%. “It is actually affordable to do it and people are not going to have to sacrifice their aspirations about improved standards of living,” said Professor Jim Skea, co-chair of the IPCC, “It is not a hair shirt change of lifestyle at all that is being envisaged and there is space for poorer countries to develop too.”
On a more controversial note the report takes a more positive view of investment in gas. Many environmentalists argue against investing in gas, for fear it would lock us into a high-carbon future compared with renewables. However, the latest IPCC report seems to accept the gas argument by saying:
"Greenhouse gas emissions from energy supply can be reduced significantly by replacing current world average coal‐fired power plants with modern, highly efficient natural gas combined‐cycle power plants or combined heat and power plants, provided that natural gas is available and the fugitive emissions associated with extraction and supply are low or mitigated (robust evidence, high agreement)."
It can be argued that an abundance of cheap gas puts competitive pressure on renewables and nuclear and offers a short-term bridge to a low carbon future. Producing electricity from gas gives of about half the CO2 emissions of coal and as coal is still a dominant fuel source in many countries in the world switching to gas would reduce their CO2 emissions at lower costs than switching to renewables. While this may be a strategy for the developing world that doesn't just justify fracking in Scotland, or environmental or economic grounds.
Equally controversial in environmental circles, the report also recommends that nuclear power can make an “increasing contribution to low-carbon energy supply”, though they accept this is not without its ill-effects on the environment.
Overall, the IPCC report is a very clear wake up call to the world that measures taken to date are simply not sufficient to halt global warming. The scientific evidence is overwhelming, leaving little room for climate change sceptics. However, the report is also pragmatic on energy issues like gas and nuclear and that will be a challenge for some in the environment lobby.