The climate change challenge
The world is getting warmer as a result of human activity. Global emissions and the increase in temperature since 1850, the beginning of the second phase of the Industrial Revolution, are shown in the graphic below.
Emissions and global temperature rise since 1850
Source: Climate Levels
The impacts of climate change have been felt in all parts of the world in recent years. Extreme weather has become more frequent and more intense, causing a range of devastating events including droughts, wildfires and flooding. Examples of these climate change threats in different parts of the globe are shown in the graphic below.
Climate change threats in different regions
In 2021, the UN’s Intergovernmental Panel on Climate Change (IPCC) issued a stark warning about the deepening climate emergency, suggesting it would already take centuries for some changes to be reversed.
The IPCC’s Sixth Assessment Report highlighted the scale of the emergency, noting that changes were already having an impact on every region of the planet. Every fraction of a degree of global warming has an impact, which is why many governments have pledged to reduce global emissions to net zero as quickly as possible.
These pledges were committed to paper under the Paris Agreement and adopted by 196 parties at the COP21 UN Climate Change Conference in Paris in December 2015. It is a legally binding international treaty on climate change that aims to limit global warming to well below 2C, preferably to 1.5C, compared with ‘pre-industrial’ levels.
The graphic below shows the forecast effect on global temperatures, dependent on action taken. The blue forecast illustrates the optimal path that would be achieved by adhering to the pledges.
Source: Climate Action Tracker
The UK and decarbonisation
The UK government has made a legal commitment to reduce emissions from carbon dioxide and other greenhouse gases. This is enshrined in the Climate Change Act 2008, which commits the UK to reducing greenhouse gas emissions by at least 100% of 1990 levels (i.e. net zero) by 2050. It includes reducing emissions from the devolved administrations of Scotland, Wales and Northern Ireland, which together account for about 20% of the UK’s total emissions.
Under the Climate Change Act, the government must set legally binding ‘carbon budgets’ to act as stepping stones towards the 2050 target. A carbon budget is a cap on the amount of greenhouse gases emitted in the UK over a five-year period.
These budgets are designed as a cost-effective way of achieving the UK’s long-term climate change objectives. Once a carbon budget is set, the Climate Change Act places an obligation on the government to prepare policies to ensure it is met.
Climate change in the UK
The act also established the Climate Change Committee to ensure that emissions targets were evidence-based and independently assessed. It requires the government to assess the risks and opportunities from climate change for the UK, and to adapt to them.
The act contains a requirement for the government to produce a UK Climate Change Risk Assessment every five years that assesses current and future risks to, and opportunities for, the UK from climate change. The government must also produce a National Adaptation Programme for England, while the devolved administrations produce their own programmes and policies.
The government’s Green Book sets out Treasury requirements for business cases that seek public funding, including for infrastructure projects and programmes. A review of the Green Book was published in November 2020 that included updated guidance on the appraisal of projects, programmes and policies based on their alignment with net-zero carbon emissions targets.
Under revised Green Book requirements, the whole-life carbon emissions impact from all proposed projects should be assessed and quantified at the earliest stage, typically in tonnes of carbon dioxide equivalent.
Who is responsible for climate change policy in the UK?
The Cabinet Committee on Climate Change outlined that all government departments should include climate change in their thinking when making policy decisions. The two main departments responsible for climate change are shown in the graphic below.
The governments and assemblies of the devolved administrations create climate change policy for their own devolved areas, as well as helping to implement UK-wide policies. They are covered by the Climate Change Act but also have their own climate change policies:
- England is covered by the UK Climate Act 2008 and is committed to achieving net zero by 2050 within that framework.
- Northern Ireland does not have specific climate change legislation and contributes to the UK target under the Climate Act 2008. Climate change legislation is being considered, based on advice from the Committee on Climate Change, in relation to Northern Ireland’s contribution to UK net zero by 2050.
- The Climate Change (Scotland) Act 2009 commits Scotland to net-zero emissions by 2045. This includes a 56% reduction by 2020, 75% by 2030 and 90% by 2040 against the baseline. There is also a requirement to produce a Scottish Climate Change Adaptation Programme.
- The Environment (Wales) Act 2016 introduced a duty on Wales's government to develop carbon budgets for the country and to reduce emissions by at least 80% by 2050. It has since committed to achieving net-zero emissions by 2050, and is pushing to get there sooner.
Standards and guidance
There are various standards and guidance documents that support carbon reduction. Those listed below are the most relevant for civil engineers based in the UK.
Net Zero Strategy: Build Back Greener
Published in October 2021, this sets out the UK government’s long-term plan for transition to a decarbonised economy by 2050. It includes a delivery pathway that gives indicative emissions reductions across different sectors to meet the targets for the Sixth Carbon Budget (2033-2037), including buildings and transport.
The Climate Change Committee’s 2022 progress report to Parliament says that, while the UK government now has a solid net-zero strategy in place, important policy gaps remain and greater emphasis and focus must be placed on delivery.
Infrastructure Carbon Review
This sets out a series of actions for government, clients and suppliers to reduce carbon from the construction and operation of the UK’s infrastructure assets, in line with the UK’s climate change commitments.
The recommendations have the potential to reduce up to 24m tonnes of carbon a year and save the UK £1.46bn a year by 2050. The review was developed jointly by government and industry though the Infrastructure Working Group of the Green Construction Board.
The Construction Playbook
This sets out key policies and guidance for how public works projects and programmes are assessed, procured and delivered.
One of its aims is to help the UK move towards its 2050 net-zero commitment, using whole-life carbon approaches to reduce carbon emissions linked to buildings and infrastructure and within the construction supply chain.
The Building Regulations 2010
The Building Regulations set standards for the design and construction of buildings in England and Wales to ensure the safety and health for people in or about those buildings.
In July 2021 the construction industry proposed an amendment, known as Part Z, to regulate carbon on all major construction projects. The amendment, which is still undergoing review, would require whole-life carbon assessments and compliance with capital carbon limits for projects greater than 1,000 square metres (or 10 dwellings).
The principle of introducing carbon regulations is supported by more than 150 organisations involved in the UK construction industry, including the ICE.
BREAAM
The Building Research Establishment Environmental Assessment Method (BREEAM) is a suite of validation and certification systems for assessing the sustainability of new or existing buildings. It assesses projects against a range of sustainability criteria – including capital and operational carbon emissions – and gives a rating from ‘acceptable’ to ‘outstanding’.
BREEAM is owned by the UK’s Building Research Establishment and operates in many countries around the world. It supports solutions to decarbonisation in the built environment.
BREEAM Infrastructure is a method of assessing, rating and certifying the sustainability of buildings.
ISO 14001 Environmental Management System
ISO 14001 is a suite of standards setting out the criteria for an environmental management system. The standards map out a framework that companies and organisations can follow to set up an environmental management system.
Organisations can be ISO 14001-certified, and there are currently more than 300,000 certifications to ISO 14001 in 171 countries.
PAS 2050:2011 Specification for the assessment of the lifecycle greenhouse gas emissions of goods and services
PAS 2050 is a specification for assessing the carbon footprint of goods and services over their lifetime. It was developed by the British Standards Institution (BSI) in 2008 and revised in 2011.
PAS 2060: 2014 Specification for the demonstration of carbon neutrality
PAS 2060 is an internationally recognised specification detailing how to demonstrate carbon neutrality. It was developed by the BSI, building on other environmental standards such as ISO 14001 and PAS 2050.
It sets out requirements for quantification, reduction and offsetting of greenhouse gas emissions for organisations, products and events. Companies can self-certify to PAS 2060 or seek third-party verification.
PAS 2080: Carbon management in infrastructure
PAS 2080 is the world’s first standard for managing carbon in building and infrastructure.
It looks at the whole value chain and aims to reduce carbon and cost through intelligent design, construction and use.
The standard offers a common language and framework for asset owners and managers, designers, constructors and suppliers to manage whole-life carbon. It also highlights the importance of strong leadership and early supplier engagement.
PAS 2080 provides guidance on setting targets and also establishes stages throughout the infrastructure delivery lifecycle where leaders should challenge their supply chain to achieve the greatest carbon and cost benefits.
Culture change
The climate crisis presents the engineering profession with the biggest challenge it has faced. To help stave off environmental catastrophe, engineers need to completely rethink the infrastructure they provide and how it is delivered. They need to offer alternatives that do not deplete the world’s resources or contribute to carbon emissions.
Engineers should provide infrastructure that actively encourages a shift to low-carbon behaviours. A carbon net-zero world will involve changes in lifestyle that may currently seem unimaginable but will soon become routine. Engineers need to adapt and provide the infrastructure that will enable this to happen at speed.
PAS 2080 gives engineers a hierarchy for reducing carbon emissions that should be followed for every project, asset or programme they work on. The hierarchy consists of four options, shown in the graphic below.
Carbon reduction potential across the carbon hierarchy
At first glance, the options proposed in the carbon reduction hierarchy might seem like a threat to the civil engineering profession. Suggesting a no-build solution seems to call into question the whole basis of the profession and the work it does. But, as the ICE’s State of the Nation 2021: Six Ways for Civil Engineers to Act on Climate Change report explains, it does not mean the end of the profession.
“This is the moment when we rise to the challenge, with civil and infrastructure experts at the very heart of the transformation needed to break the many links between infrastructure and carbon,” the report says. “The problems presented by the climate emergency present an opportunity for engineers to take a more creative, collaborative and holistic approach.”
But engineers will have to think and act differently. As the report points out: “Some skills that have been valued highly in the past will become less important, while others will be needed: collaboration; understanding of human behaviour; systems thinking; knowledge of how to adapt existing structures; asset operation; and community engagement.
"Civil engineers need to be able to promote their design ethos and the impact of their solutions on people and the environment, and to see their projects in a wider context. And they will have to learn how to work with a diverse group of experienced people. Carbon literacy will be a crucial skill set. “
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