Incessant squabbling between advocates of classical and modernist architecture is an unhelpful distraction in the face of the climate emergency, which requires us to escape both, writes Barnabas Calder.

Last week the century-old squabble between modernism and historicism raised its tired old head once again after a UK government minister backed a report advocating a more "tradition"-friendly new architecture school. But in the bright light of climate emergency, it's clear that both sides in this venerable battle of the styles are equally wrong.

We all know that buildings are responsible for 39 per cent of anthropogenic carbon emissions globally, and that we need to radically and urgently decrease both operational and embodied carbon if we're to keep climate warming from hitting catastrophic levels.

There is only one crucial divide in architecture: architecture that is dependent on heavy fossil fuel inputs, and architecture that isn't

It's time, therefore, to recognise that there is only one crucial divide in architecture: architecture that is dependent on heavy fossil fuel inputs, and architecture that isn't. Georgian terraces and Brutalist towers, Victorian Gothic and Foster's Bloomberg HQ – all are part of the same architectural movement: Fossil Fuelism. And we need to escape it fast.

Fossil Fuelism – architecture dependent for its creation and operation on coal, oil or gas – is the weird exception in architectural history. For millennia, humans built using muscle power as the biggest input. Wherever possible they avoided using heat from scarce, slow-growing, expensive firewood. Heat-processed materials like fired brick or metals were used when overwhelming technical reasons demanded it, or when a rich client like the Shah of Iran wanted to really show off, as in the case of the Sheikh Lotfollah Mosque's extravagant tiles.

More representative were the famous carpentry traditions, whether Japanese, Chinese, Maori or Tudor, which mustered extraordinary ingenuity and skill to avoid the heat cost of making metal nails. Using glass for windows was an outrageous luxury reserved for the most powerful and affluent.

People in areas without local building stone accepted the ongoing maintenance obligations of mud brick and reed thatch rather than spend scarce heat on longer-lasting fired brick and tile.

In the absence of diesel lorries, almost all materials were sourced very locally. Roman Emperors boasted by bringing beautiful stone long distances to decorate their most important projects, but even these were just a thin skin over a building made up of more local materials. Seventy-six per cent of the Baths of Caracalla's volume of materials came from within 20 kilometres of its site in the centre of the world's greatest metropolis. Only 0.5 per cent of the building was actually made up of the flashy marble it was coated in.

London's reconstruction after the Great Fire emitted around 300,000 tonnes of embodied carbon

In completed buildings, comfort was achieved by negotiation with the climate: in hot places siestas might be needed, with social and working life clustered into the cooler hours. In cold places people would wrap up in warm clothes, and heat themselves by gathering round a precious fire, rather than warming all the air in the building to an invariant "thermal beige".

That all changed in 17th-century London, where rising availability of cheap coal from Newcastle, and the Great Fire of 1666, led to the deliberate adoption of a new energy-hungry architecture: coal-fired brick, coal-calcined lime mortar and coal-glass windows. The resultant houses were heated through the long, cold winters by open fires burning more coal, with 90 per cent of the cheap heat disappearing wastefully up the chimney.

London's reconstruction after the Great Fire emitted around 300,000 tonnes of embodied carbon from brick and lime production, and domestic coal consumption in the city produced around 600,000 tonnes of emissions per year by the 1670s, for a population of half a million.

Over the following three-and-a-half centuries the range of things that fossil fuels can make our buildings do has increased, but the fundamentals remain the same. This is architecture built of materials that are made through the consumption of huge amounts of energy, and producing an ever-narrower definition of "comfort" for those within, through heavy operational energy inputs.

Even most of the architecture given high marks by our sustainability assessment systems is dependent on heat-hungry production processes for concrete, steel, aluminium, plastics and excessive glazing, very often with HVAC systems continuing to pump away within, albeit somewhat more efficiently than a few decades ago.

In this context, the UK version of the fight between "tradition" and "modernism" seems absurd: Georgian architecture is not traditional at all, but the founding phase of modernism – the first generation of architecture to be entirely and gleefully dependent on heavy use of cheap fossil fuels.

Georgian architecture is not traditional at all, but the founding phase of modernism

If we want to learn from traditional architecture we need either to look back further in the history of long-industrialised countries – Tudor and medieval English architecture, for example, was mostly genuinely circular, renewable, zero-carbon and low-energy – or look to areas of the world whose dependence on fossil fuels has arrived more recently, and whose traditions therefore survive.

The extraordinary work of Yasmeen Lari's Heritage Foundation of Pakistan leads the way: it helps rural people in Pakistan to construct new housing after natural disasters, and does so using local funding and very low-carbon techniques and materials – earth, bamboo, and a little lime.

If some of the poorest people on earth, who have contributed least to the climate emergency, can build very low-carbon housing at their time of greatest need, how much more ought we in the rich world be redoubling our efforts to legislate, design and build for radical carbon reduction?

We do not need to go back to pre-fossil-fuel discomforts, let alone dangers. Our material understanding is far greater – the options for what Michael Ramage describes as a "vegetarian diet" for architecture are growing by the month through excellent research and experimentation.

And even if we switched off fossil fuels tomorrow, our renewable electricity resources would make us far more energy-rich than our ancestors. But we do need to ask of everything the fundamental question: "how can this be decarbonised?", and be governed by the answer, whether it requires regulation, restraint, technical change or lifestyle adaptation.

We all have things to contribute to this great and exciting challenge. Lovers of Fossil Fuelism have things to offer in learning how to adapt architecture round rapid shifts in energy systems, as Fossil Fuelism has repeatedly done over 450 years of constantly accelerating change. Experts in pre-fossil-fuel traditions have lessons to teach us about the durable use of low-energy materials, and about achieving comfort without such heavy energy inputs.

This is no time to be distracted by quarrels between modernists and neo-Georgians about whose inadequately-shaded windows are prettier. There are bigger issues at stake.

Barnabas Calder is head of the Architectural and Urban History Research Group at the University of Liverpool, and author of Architecture: From Prehistory To Climate Emergency and Raw Concrete: The Beauty of Brutalism. He is a trustee of the Society of Architectural Historians of Great Britain.

The photography is by Siddhant Kumar via Unsplash.