Cambridge needs more development in the city to help reduce its residents’ environmental impact
Meeting emissions targets
The UK Government has committed to reaching net zero emissions by 2050, in line with the 2015 Paris Agreement. Cambridge City Council has set the yet more ambitious target of reaching net zero by 2030 – a mere eight and a half years away. Between 2005 and 2019, Cambridge’s greenhouse gas emissions in tonnes of CO2 equivalent fell from 6.7 per person to 3.9 – an average reduction of about 3.5% per year. At this current rate, it would take until 2039 for Cambridge to actually reach net zero. Clearly, more work must be done if the city wants to hit its target. What’s more, these figures only include Scope 1 & 2 emissions (more direct, measurable emissions) and not the total level of emissions all along supply chains – Scope 3 emissions. This means the actual challenge is larger than the published data may suggest.
Between 2005 and 2019, per person greenhouse gas emissions in Cambridge fell by 41%, despite the city’s population growing by nearly 70,000 in the intervening period. Cambridge could potentially learn lessons from regional neighbour Ipswich, which saw a 52% reduction in per capita emissions over the same period. Most of this fall was due to greater efficiency in the industrial and commercial sectors, where emissions fell 50% over that period. Domestic emissions fell 36%. But transportation remains the lagger, with emissions falling barely 4% over 15 years. Journeys using non-main roads were the worst offender, seeing an 11% increase in emissions over the same period.
Denser living is greener living
The new housing supply on the horizon is largely focused on delivering large, relatively low-density sites on the city fringe and the hinterland beyond. It’s an inconvenient truth, however, that these sort of sites tend to be worse for the environment, as greater reliance on cars for transport means emissions per person tend to be much higher than in denser, more central locations.
Suburban homes have seen increasing popularity over the past year, as lockdowns and shifts to working from home have reduced the appeal of city centre life. While many will be expecting to commute less, commutes only account for 14% of car use. The greater distance to amenities and services means a household’s transport emissions likely increase after such a move, even with a significant reduction in commuting into town. No small issue, with road use remaining the highest growth source of emissions in the county.
Focusing on increasing residential density in the city centre would help Cambridge reach its net zero targets. But given the heritage challenges of building centrally, the bulk of new housing will continue to be on the edge of the city. This will mean more journeys to and from the city centre, even if the current trend of working from home continues. Facilitating these journeys in a sustainable manner, such as with regular environmentally friendly buses, will be a priority going forward.
While the council has various plans to reduce emissions, such as installing heat pumps and solar panels at leisure centres, using low carbon heating and switching to low emission council vehicles, there is clearly a lot of progress to be made.

The costs of going green
Cambridge does not sit in a vacuum, and the wider region will need to address the efficiency of its housing stock. Our analysis suggests there are 114,000 homes across Cambridgeshire with an EPC grade of D or below. Within the city, many of these homes will be used by the colleges to house students. Upgrading all homes to at least EPC C standard could reduce CO2 emissions from 939,000 to 542,000 tonnes per year, a fall of 42%. We estimate the total cost of upgrading these homes would be about £1.6bn. For context, Government had earmarked £2bn funding in its now axed Green Home Grant scheme.
The distribution of housing quality and type varies across Cambridgeshire. 47% of homes in Cambridge are EPC D or below, while 58% of homes in Fenland are D or below. There is an inverse relationship between the number of homes in need of upgrades and the economic output of an area. Thus Fenland, the authority with the lowest economic output in the county, would find itself paying 12.2% of its GVA just improving housing stock to meet the new standards, compared to (much richer) Cambridge’s 3.6%. The distribution of costs for meeting environmental standards is loaded against the areas least able to pay.
An even greater challenge is ensuring the colleges themselves are kept in line with requirements. Trinity College has pledged to reach net zero by 2050, and aims to divest itself of fossil fuel investments by the end of 2021.
Many of the 16th and 17th century buildings that make up the college were not built with the 2015 Paris Agreement in mind, however. Renovating them to increase their energy efficiency, while maintaining their character will likely prove an impossible task.
Given the colleges’ landholdings around Cambridge, a more feasible approach may be to invest in renewable energy generation through solar, wind and biomass, and using this green energy to heat and power these buildings. This would reduce the scale of intervention needed in historic city centre buildings, though colleges would still need to replace gas heating and boilers with electric.
Read the articles within Cambridge: Thriving on Innovation below.