Modern heritage practice has largely operated through visual continuity when it comes to historic gardens. We view them as stable time capsules that offer a reprieve from the chaos of the modern world, an experience that is often easy to understand and, above all, familiar.

In the context of accelerating climate change, this logic becomes unstable. As the world changes, so does our relation to certain notions. All sorts of antagonisms are constantly being reframed to help us process the state of affairs in the current moment; from geopolitics, to culture, to identity politics, to colonial aggression, and to the idea of Nature. Gardens are especially productive in this respect. And not just how we build now, but how ideas behind decades and centuries of landscape architecture have accumulated and are now under environmental pressure.

Ecological systems no longer support the conditions under which many heritage sites were conceived. The commitment to cosmetic continuity increasingly requires substitution, replacement, and technical adjustment to sustain the appearance of permanence.

In the neo-baroque parterre at the protected Arboretum Volčji Potok, Chamaecyparis lawsoniana hedges and cones began to die under prolonged summer heat. The response from the management was consistent with conservation practice: replace them with a more heat-resilient Thuja variant in order to maintain the formal structure. Formally, the intervention is discreet, but conceptually, it reveals an issue; the design is being adapted so that visual permanence is maintained through substitution. In other words, the image remains stable, but the ecological basis has shifted.

An alternative would not be to dramatise or aestheticize decay, but simply to resist correcting it—to refrain from replacement and allow the incompatibility between past and present to remain visible. The failure would become part of the site’s meaning rather than something concealed for the sake of appearances. In cities, we can replace dying trees indefinitely, but heritage sites—maintained to appear stable and timeless—offer a particularly potent perceptual platform where the effects of climate change can become visible.

At Rousham, preservationists oppose a large-scale development at Heyford Park, a former RAF airbase now proposed to accommodate housing, industry, and renewable energy infrastructure. The scale of transformation raises legitimate concerns regarding territorial pressure, infrastructure, and ecological impact.

Yet beyond the planning debate lies a deeper issue. Rousham is often described as “unspoilt,” but it stands beside a landscape long shaped by military runways, geopolitics, and contemporary settlement. The horizon appears pastoral, but what remains unseen are the systems that have sustained it—agricultural labour in the 18th century, military infrastructure in the 20th, and atmospheric and demographic pressures today.

The resistance to visible energy infrastructure, such as the three tall wind turbines that are a part of the plan, exposes a desire to preserve the image of a stable rural horizon—as if energy, housing demand, and climate were external to the site. This is not an endorsement of the development scheme, nor a dismissal of legitimate concerns about scale. The issue is different: how heritage imagines its horizon in relation to the systems already structuring it.

Weren’t the English landscape gardens conceived precisely as relational constructs? They framed the surrounding world rather than isolating themselves from it. The 18th-century picturesque harmonized working agricultural land shaped by labour, extraction, and estate management. Pastoral calm was always constructed. If the surrounding world now includes post-military reuse, renewable infrastructure, and housing, excluding these from view may preserve scenic coherence but sustain the fiction that heritage exists outside contemporary systems. There is no “away”; the world is already inside the garden.

The conflict exposes a larger question: is authenticity and historic autonomy located in the protection of a once-existing pastoral horizon, or in sustaining the garden’s structural openness to its contemporary environment?

If heritage is premised on continuity and stability, climate change introduces structural discontinuity and instability. The incompatibility between these temporalities cannot be indefinitely resolved through replacement and aesthetic maintenance. It is at this point that preservation becomes simulation.

In conferences, lectures and publications, we often make projections about our climate futures; how many places will end up underwater, which tree species will retreat, and how severe the storms will be. That world is already here. We no longer need to project scenarios in order to awaken or inform those we consider distracted; we must also reveal. The question is, how will landscape architecture intervene in aesthetic terms? By masking the cracks in the background, as so many failing projects have done before their demise? What is the social role of heritage in a climate crisis, and with that, the role of landscape architecture?

We need to let the image be disturbed—even completed by less pleasant confrontations—to remind us that the precious things we are trying to preserve are falling apart more fundamentally. We keep demanding from ecology to smile through landscape, and seldom consider that the necessary changes to our being-in-the-world will not necessarily come as “friendly ecology” but as an unsettling list of inconvenient restrictions and changes to our lifestyles. We speak easily of planting more trees, yet we rarely speak of consuming, replacing and making less. What we throw away returns as microplastics; the more we build, the heavier the carbon footprint. When these heritage sites were built, the sky was the limit. Today, we know how limited that sky is.

The Still Alive project – a temporary garden in Aglie, near Torino, Italy, represents one possible direction of how such interweaving of temporalities may look in practice. Within a historic garden, Wagon Landscaping introduced a small “low-resolution” circle. This circle features invasive species, construction waste, asphalt, and various artifacts of the Anthropocene. A second circle introduces a mowing regime for maximum biodiversity.

It acts as a puncture where the future—and the reality of the world outside—leaks into the past. It interrupts the old with the introduction, or better, intrusion of today. It serves as an “ecological saboteur”, a necessary reminder that climate change is omnipresent even when it is imperceptible, and that visual harmony has little to do with planetary health.

Climate has always shaped landscape, architecture, social practices, agriculture, meaning … When climate shifts structurally, the cultural frameworks built upon it cannot remain untouched. As the stable Genius Loci becomes frail with the change of climate, a move toward a Genius Mutabilis, a cultivated sense of change, seems more promising. The reframing of heritage sites should make the incompatibility of these temporalities visible by acknowledging that the old harmonics can no longer operate. Such a paradigm shift would increase the social role of not only cultural heritage sites, but landscape architecture itself.

Precisely because landscape architecture deals with perception, and because carbon and microplastics remain invisible, the discipline can intervene to make the damage perceptible. This intervention unsettles the immunity traditionally granted to heritage and interrupts the false certainty of continuity. It opens a portal into ecological reality from landscapes that may otherwise seem unconcerned with the issues of today. Landscape architecture should not conceal the damage it cannot repair.

We must alter the criteria of Visual Impact Assessments: in the Anthropocene, infrastructure that participates in environmental health, for the better or worse, may demand a visible presence. Visual Impact Assessments must measure ecological denial so that the authenticity of experience includes climatic incompatibility.

Today we know that the ambition to compose landscapes of timelessness rested on an assumption of environmental stability—the belief in limitless skies and inexhaustible capacity. Historic gardens are not external to this condition. It is not that ecology “happened to them” from outside, leaving them as collateral victims of an extractive world. They were conceived within that very cosmology of limitless sky that relied on abundance and extraction, that harmonized a cultural image of Nature into our collective consciousness.

Disturbing the tranquillity and visual stability of heritage sites can therefore be understood as a necessary acknowledgement of the limits of that cosmology. These landscapes were an answer that appeared coherent in their time, but no longer holds in the 21st century. Reframing heritage sites requires us to trade the illusion of safety, where we bathe in simpler times, for the reality of the Genius Mutabilis.

They must become places where we register the distance between a vanishing past and a contingent future. To recognize the limits of the sky is therefore not to betray the past, but to understand why it can no longer continue unchanged.