Decarbonising the built environment

Jonathon Porritt CBE, environmentalist and writer, speaks at our first #TTNewLeaf Lecture.

With the 26th UN Climate Change Conference of the Parties (COP26) taking place in Glasgow next month, Jonathon Porritt CBE, the renowned environmentalist and writer, delivered our inaugural #TTNewLeaf Lecture on decarbonising the built environment.

During the talk, Jonathon outlined his thoughts on the scale of the climate challenge, the implications and opportunities for the built environment and what we can expect from COP26.

In the context of restricting the rise in global temperatures to no more than 1.5 degrees Celsius between now and 2100, he considered the impact that chronic cognitive dissonance, multiple overlapping time lags and the inevitable policy response are having on climate efforts. 

Although the imperative to limit greenhouse gases and mitigate the impact of climate change may be a relatively new issue for governments to grapple with, efforts to address it span decades.

The challenge, Jonathon said, is that “all governments suffer from chronic cognitive dissonance” when it comes to facing the scale of action required and finding a “path to reconcile our past and our present.”

Speed of climate response

Jonathon expects that over the course of the COP26, chronic cognitive dissonance will be visible and much of its success will depend on how effective governments are at addressing it.

The speed at which scientific data is translated into real world policy has a significant bearing on climate mitigation efforts. This is where cognitive dissonance has a significant impact.

As Jonathon pointed out, the “policy is always a decade behind the manifestation of scientific evidence in the natural world”, meaning that what we are enacting today has been developed to address the issues we were first seeing ten years ago. Jonathon referred to this as “multiple overlapping time lags”.

Raising the alarm 

The Intergovernmental Panel on Climate Change (IPCC), the body responsible for making sense of all the climate related scientific data, released the first part of its sixth assessment report Climate Change 2021: The Physical Science Basis in August this year.

Highlighting the speed of change we are witnessing and its potential impact, Jonathon said that the report “could not have raised more red flags about our current status”.

Many scientists now believe it is absolutely inevitable that sea levels will rise by a minimum of two metres by the end of this century and that this scenario “will play out dramatically in the built environment”.

Given this combination of chronic cognitive dissonance and multiple overlapping time lags stalling the pace of essential action, Jonathon said that a moment will come for an “inevitable policy response”.

We have not reached this tipping point yet, but at some stage events will force the hands of politicians and they will have to “dramatically change the combined effects of policies to meet the speed of climate impact.”

Getting to net zero

When we consider the above, it is possible to see how we need to raise our own game. Jonathon asserted that “we already have the resources we need to make this a success story”, adding that we know “everything we need to get to net zero by 2050.”

Technology has a critical role to play. The global construction sector is responsible for 40 percent of greenhouse gas emissions; currently, 25 percent are operational, and 15 percent are embodied.

Jonathon expects this to pivot, so that by 2035 these figures will be switched round and those in the sector need to think fast about how they manage embodied carbon.

Perception is still a significant challenge. Carbon reduction is still being seen as a cost and a constraint. The numbers “have got to be flipped if we are going to close the gap between science and delivery”, otherwise we will fail to reach our net zero goals.

Climate resilience is particularly important in the built environment given the lag between scientific data and policy implementation. Jonathon said that for new build offices, assuming an asset lifespan of 30 to 40 years, construction projects one metre (or less) above sea level are increasingly going to be seen as high-risk investments.

Likewise, we will now have to give serious thought to when specific cities become unviable.

Closing on COP

If we have all the tools we need to effectively tackle climate change, then all we need now is to secure the political will and public opinion.

In this regard all eyes will be on COP26. Jonathon believes that a good outcome of the climate summit will be to have a “reminder that America is back in the game”, providing intelligent responses to the climate emergency. Seeing “a different America to previous COPs” will help drive international collaboration.

The success of the summit will also be measured on whether delegates secure the $100bn funding for the climate finance pledge. This would be a “big break”, according to Jonathon, in the race to limit global temperature increases and sea level rises.

For further information contact:

Ben Steele
Senior Communications Manager

t: +44 (0)20 7544 4553
e: