The Manchester branch of Friends of the Earth has none too happy with the government's proposals to look at raising the speed limit on the nation's motorways
Here is their press release
Manchester Friends of the Earth is dismayed by the proposals outlined by Philip Hammond, Secretary of State for Transport during the Conservative Party conference to allow 80 mph speed limits on the UK’s motorway network.
The Minister has claimed that increasing the motorway speed limit to 80mph would “generate economic benefits of hundreds of millions of pounds through shorter journey times."
Manchester Friends of the Earth believes the Minister appears to either be unaware of, or be ignoring, evidence from both his own, and other government departments that has shown that increasing motorway speed limits will:
Increase the number of people killed and injured on the strategic road network.
The Transport Committee report on Road Traffic Speed estimated that raising the motorway speed limit to 80 mph would lead to an increase in motorway casualties of between 5 and 10 per cent. This indicates that a change in the limit would lead to between 50 and 115 more people killed and seriously injured per year.
Waste more fuel.
According to the Department for Transport driving at 70mph uses up to 9% more fuel than at 60mph and up to 15% more than at 50mph. Cruising at 80mph can use up to 25% more fuel than at 70mph.
Cause more air pollution.
In 2011, the GM Air Quality Strategy Plan acknowledged that the motorway network around Greater Manchester was one of two areas that was breeching the EU limit value of 40μg/m3 for NO2 air pollution.
Have a higher impact in poorer communities.
A 2006 study found that the most deprived areas had some of the highest levels of NO2 and PM10 pollutants and that this air pollution was “driven by road transport sources”.
Cause higher C02 emissions.
In June 2011, the UK Committee on Climate Change (an independent body established under the Climate Change Act (2008) to advise the UK Government on setting and meeting carbon budgets and on preparing for the impacts of climate change) reported that a “sustained increase in speeds would significantly increase emissions (e.g. an 80mph speed limit could result in emissions up to 3.5 MtCO2 higher than restricting speeds to the current limit)”  The Committee recommended a reduction in motorway speed limits to 60mph.
The transport sector is responsible for 25% of the C02 emissions in the United Kingdom  and enforcing the current speed limits or reducing speed limits would provide considerable CO2 emission reductions. 
Graeme Sherriff, Manchester Friends of the Earth Transport campaign co-ordinator said:
“The proposed speed limit increase is being justified on economic grounds, but it is unfortunately likely to result in more deaths and injuries on the roads, worse air pollution, and increased climate change emissions. It would make a mockery of evidence from the minister's own department and fly in the face of the Government's aspiration to be in the 'greenest government ever’.”