Towns and cities across the South West will see a massive increase in carbon dioxide emissions, the main cause of climate change, unless thousands of new homes planned for the next 20 years are built to high environmental standards.

According to the conservation lobby group WWF-UK, Exeter will see the highest rise in emissions. The area should expect a 24% increase in domestic carbon emissions, if proposals to build 18,500 new homes between 2006 and 2026 are delivered to current minimum standards.

In Plymouth, figures show that the development of 31,500 homes would result in an 18% increase while in Taunton about 14,000 new homes would lead to approximately a 17% rise. This compares to a 12% average increase across the rest of the South West.

However, new research by WWF shows that if all future developments are built to high environmental standards and existing good practice this could be reduced by around 30%.

The news comes as two major new settlements planned for Devon are opting for contrasting approaches to tackling the threat of climate change. The group criticised plans for a major settlement in Cranbrook near Exeter foir failing to meet the eco-homes "very good" standard.

Mark Ellis-Jones, WWF's Regional Development Officer, said: "How we build new housing today will shape the way people live and work for many years to come."

"Currently, our homes are responsible for about 27% of all the UK's CO₂ emissions. If we are serious about tackling climate change new housing must enable householders to reduce those emissions."

WWF's One Million Sustainable Homes campaign is calling for all future developments to meet the EcoHomes 'Very Good' standard as a minimum, and for the use of 'Sustainability Checklists' to accompany major planning applications.