A branching approach to net zero

Getting to net zero emissions requires a paradigm shift in the way that we think and in the way that we do business collaboration between climate resilience, decarbonisation and improving biodiversity along with systems thinking could deepen efforts to reduce global carbon emissions, improve our natural environment and protect society from the impacts of climate change.

This is critical as the UN Environment Programme reports that progress is not happening fast enough to keep global warming between 1.5 and 2 degrees centigrade. It finds that infrastructure will absorb 88 percent of the investment needed to prevent climate catastrophe.

We have to do things differently, and recently the Green Construction Board has recognised the need to update the PAS 2080 specification to emphasise the importance of systems and accelerated enablers for decarbonisation.

The environment multiplier

Collaboration is an environmental multiplier, meaning that aligning infrastructure needs with natural processes could take us towards net zero in a sustainable way.

Net zero, the point where greenhouse gases produced are counterbalanced by those that are removed, has become a quest for countries all over the world as they strive to prevent catastrophic climate change by reducing global warming.

The UK was one of the first to write this into its national legislation in June 2019 

But despite this the UN Environment Programme reports that progress is not happening fast enough to keep global warming between 1.5 and 2 degrees centigrade. We have to do things differently.

Kim Yates is an atmospheric chemist who works as the climate change operational lead at Mott MacDonald. She supports organisations in creating action plans to get to Net Zero. But this is not all that operators in the built environment have to consider.

“We have to address climate change, we have to reduce our carbon emissions and the stakes couldn’t be higher,” says Yates. “But this is set in the context of enhancing biodiversity and also making our assets, our life, resilient to climate change. And bringing all these three aspects together is key.”

Carbon reduction, climate resilience. and enhancing biodiversity, also known as creating a biodiversity net gain. And a paradigm shift in our way of thinking and approaching this is part of it. A paradigm shift where interventions that work with nature, known as nature based solutions, and better collaboration, could potentially unlock all of the benefits that organisations are looking for: reducing carbon, creating climate resilient assets and improving biodiversity.

“We see bringing all of these three elements together in terms of nature, climate resilience, and carbon reduction are key to impacting climate change going forward. But we are also aware that if it’s not taken in the round, there can be some negative impacts,” Yates adds.

Julia Baker is head of nature services at Mott MacDonald. The UK’s Environment Act which received Royal Assent in November 2021 contains the very important step of requiring that all developments must deliver a net gain in biodiversity of at least 10 percent.

That includes both projects that fall under local planning law, and nationally significant projects permitted through a development consent order. This is expected to become effective for all projects requiring planning permission in late 2023 and for nationally significant projects from 2025.

“It’s a joint biodiversity and climate crisis. There’s no climate crisis without the biodiversity crisis, the things are so intertwined […] We achieve biodiversity net gain by following what’s called the mitigation hierarchy. We seek to avoid or minimise our impacts on biodiversity, but it’s a development project so there will be some residual losses. And then we achieve a net gain by creating enhancing restoring habitats.

“Habitats sequester carbon. So the act of achieving biodiversity net gain will impact climate change. Now, if we’re careful and if we have the right data, and if we think about biodiversity net gain in the context of climate change, we can plant, restore habitats with high carbon sequestration rates and we will have a positive impact. But if we don’t measure the impact on carbon and biodiversity net gain, if we just think about it, in a very narrow perspective on biodiversity, we could have a negative impact.”

This is a very important point to consider as the new legislation comes into effect.

“I’ve seen biodiversity net gain projects where you have a young plantation woodland currently of low biodiversity value, some of that is cleared for a development project and the biodiversity net gain enhances a degraded but more established woodland,” says Baker. “Just thinking about biodiversity that might be seeming to be a good outcome……but if that decreases carbon sequestration rates, that is far from any biodiversity net gain outcome, because its biodiversity net gain that’s making climate change worse, we have to join the dots when it comes to development projects.”

Rooftop Garden on Funan Mall in Singapore

Tricky trees

Younger trees sequester carbon as they grow. This peaks as the tree reaches maturity when the sequestration rates fall and the carbon becomes locked in. So enhancing established woodland might seem better for biodiversity and that woodland could provide an important carbon store, but planting more trees is needed to sequester more carbon over time.

Planting trees for their high carbon sequestration rates can also be needed to balance out a decrease in carbon sequestration when developments clear trees. The point that Julia is making is that biodiversity net gain and carbon must both be considered.

This means understanding the carbon sequestration properties of different habitats to really capture the best benefits.

“So we have to find that magic place in the middle, where we are achieving biodiversity net gain, and ambition for restoring nature in that particular location, but also then balance that with the urgent need to sequester carbon, but to also establish habitats that will be the carbon sinks over time,” says Baker.

Carbon sequestration projects might miss opportunities to design in benefits to biodiversity. Maria Manidaki has spent the past decade working on low carbon infrastructure. This has included co-authoring PAS 2080, the world’s first specification for low carbon management of infrastructure,  and the first sector wide route map to get to net zero created for the UK water industry.

“We’ve seen in the last few years, quite a lot of leading infrastructure owners, being in the water sector or other sectors, to really put down concrete plans to decarbonize their operations and assets with a view to achieve net zero emissions in different timescales. They have also some leading organisations have also embraced specifications such as PAS 2080 that we co-authored back in 2016, which is essentially the “how to do that” it is the behavioural piece and how to systematically manage whole life carbon, such as setting targets, baselines, challenge each other in the value chain,” says Manidaki.

“Now, in recognition of how fast this field has been moving, and I would like to quote from some recent work Mott MacDonald did for the Green Construction Board on progress for decarbonisation in infrastructure in the last seven years: “it’s good progress, but not fast enough.”

The decarbonisation landscape has moved very quickly and the PAS 2080 update encourages asset owners, and in fact anyone involved in the built environment, to think of their assets in the context of the whole system of infrastructure, buildings and the natural environment.

It is possible to have the best infrastructure engineered to modern low-carbon approaches, but it can still be vulnerable to climate-related events.

Nikki Van Dijk is a technical director and Mott MacDonald’s climate resilience lead. For her, natural solutions where the natural features of nature are engineered to solve societal problems from river restoration to manage flooding and improve water supplies, to peatland restoration for sequestering carbon are a way of combining these three disciplines.

“The common thread, or the common solution that pins all of this together is doing more with nature based solutions. And that’s where the three pieces come together for me,” says Vam Dijk. “How climate change in future is going to affect what we’re designing now. Whether that be infrastructure, whether that’d be a biodiversity net, gain habitat, actually making sure that we understand how the future is going to change and what that means for what we’re designing and creating right now is so important.”

That is not to say that natural solutions can solve every challenge. There are limitations on what is possible.

Manidaki adds, “One of the main challenges I see as at least as an engineer, is the fact that we’re relying too much on sequestration of carbon from natural solutions. This will not happen overnight. Peatland restoration could be a quick winner, but it’s important to understand the science behind these things and [initiate] them jointly.”

Data is needed before engineers can come to the answers needed, so there is a lot of work being done with academics. For example, the carbon sequestration rate of regenerative farming is not known, as Natural England has only published data on the sequestration from intensive farming.

Regenerative farming focusses on preserving the health of the top soil regenerating it and supporting biodiversity and nutrient growth. By doing this it increases the amount of organic matter in the soil in the form of fungal and bacterial microbes and decaying plant and animal tissue. There are lots of local factors influencing the soil sequestration potential meaning that data to estimate this is scarce.

“We have great data in the UK on projected climate change,” says Van Dijk. “But making sure that’s done early enough in a project and that data is shared widely enough with those who are actually designing infrastructure assets or biodiversity net gain habitats is what’s really important.”

But assessing the ‘net’ part of net zero requires low uncertainty on performance and sequestration rates, making it difficult to put together a solid business case to invest.

Baker says to really get to the heart of this issue we need more collaboration and data to create a standardised process like that which was created for carbon management in the PAS 2080 specification.

“PAS 2080 was a milestone, you know, you had to standardise, you had a process, “this is how I do it,” and it’s raising our professional standards because [we are pretty siloed],” Baker says.

This means systemic change is needed in industry and at policy level too to make sure that policy, consenting systems and technical standards are joined up.

“We need to join the dots between our professional standards. And we need to join the dots within policy. If policy is coming out with biodiversity net gain, link it to climate change, if policy is coming out about net zero, and we hear those discussions around the policy, but when it comes to the hard wording in the Environment Act, what is it saying about biodiversity net gain being climate resilient?” says Baker

And this is where industry can make a difference, says Manidaki, in demonstrating to policy makers where the gaps are and crucially how these can be closed. This is critical because regulated industries can only invest in measures that are required by law, which could prevent some opportunities for decarbonisation and climate resilience across sectors.

“I’m talking about the more transformational systemic opportunities that we’ve seen exist, such as exporting waste heat, and utilising it in district heating systems or industrial facilities,” says Manidaki. “But without the right incentives, then none of none of these things will happen quickly enough, so that we meet our targets. And that’s why it’s so important when we’re talking about systems. It’s not only the physical system of the assets, but it’s also the system of regulation, the system of government of policy of different stakeholders in the value chain. I’m a little bit sceptical of the pace of progress in this space.”

But this is where the real opportunities to make a difference lie, an opportunity to do things better, create better solutions, better infrastructure, deliver better projects. An opportunity, not a risk. And this is where infrastructure development can create very powerful benefits such as improving the ability of an area to act as a carbon sink. Baker has seen this work on projects that are embracing this collaboration.

“The original site footprint did have a lot of intensive agricultural farmland, you know, quite low grade but intensive agricultural farmland. And if you model that, according to Natural England’s published data, you know, you do see a decline in carbon sequestration over time,” says Baker.

So, if nothing was done in this area the site would have naturally found its carbon sequestration rates falling. Bringing together carbon sequestration and biodiversity net gain specialists very early on led to a solution that brought both ecological and carbon benefits.

“Historically there was woodland in that location. So they wanted to restore woodland in that location, they picked particular species that had really good carbon sequestration rates. That combination of experts around the room, the biodiversity experts choosing that particular woodland, restoring that woodland that we should see on historical maps mapped with the carbon experts to do something under biodiversity net gain had a positive carbon result at the end of it, but also, that is truly biodiversity net gain.”

Adaptation

It is particularly important to consider that over 70 percent of the infrastructure that we will have in 2050 is already built. Adaptation is critical.

“Making our existing infrastructure more resilient is one of those really big challenges,” says Van Dijk. “It wasn’t necessarily designed to be resilient to the conditions that were either seeing now or that it will be exposed to over its lifetime. There is a lot of work to be done to make sure the water keeps coming out the tap, or the trains keep running.

“Some of these solutions can be really straightforward. We had record temperatures this summer, and there’s an interesting bit of work looking at the effect on the railway and the temperature on rails. The solution can be as simple as painting sections of line white. And it ranges all the way up to the more complicated and costly solutions.”

With retrofitting, we have to look at both the simple and the transformational investments. Timing is also everything, we do not necessarily have to do everything right now, but it is important to know what is required and when. And to be agile enough to change pathway when warranted.

“And that’s such an important point for biodiversity net gain,” says Baker. “Because we might say, “Well, look, this area might be too flooded for woodland”. Do we just go to something else completely like a reed bed, or do we stick with woodland but build into the management plan those checks, that thinking. Maybe make a mosaic of wet woodland or there might be drainage options.”

Another danger of carrying out work in a market where policy and standards are immature is that of greenwashing – being able to make claims about the sustainability of projects because accountability is vague. A company might have simply offset its emissions and not actually reduced its carbon output.

From policy to regulation to working in an interdisciplinary way within businesses, to researching and gathering the data needed to understand mitigation measures for the climate emergency, collaboration is the key to unlocking net zero.

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