A new global review argues passive cooling technology must become central to climate adaptation.
As temperatures rise around the world, air conditioning is saving lives. But a growing reliance on it is also placing unprecedented pressure on electricity grids, increasing greenhouse gas emissions and making cities even hotter.
A global review led by UNSW Sydney's Professor Mat Santamouris AM – an expert in innovative heat mitigation technologies and strategies for cities, opens in a new window – argues that keeping buildings cool without relying solely on air conditioning will be critical for adapting to climate change.
With 10 systems purchased every second worldwide, the University of NSW professor fears the cooling technology has become the default response to rising global temperatures.
"We cannot air-condition our way out of climate change," he said.
"If every building depends entirely on mechanical cooling, we create enormous pressure on electricity systems while adding even more heat to our cities."
Passive cooling technologies reduce heat and solar gains in buildings and public spaces while dissipating excess heat. This approach could reduce impacts of mechanical air conditioning, which has environmental impacts and consumes electricity, contributing to peak demand and grid stress. In this Review, we discuss advances in passive cooling technologies, focusing on smart solar control, ventilation, and radiative, evaporative and hybrid dissipation systems.
RESEARCH PATHWAY: personal reflections on a career in research
Mat Santamouris (University of New South Wales) reflects on a research journey explaining how an early fascination with solar energy and building physics evolved into research on urban overheating, cool materials, and city-scale heat mitigation. The social imperative for research to address now is: Who is most exposed to extreme heat, and what can science do to protect them?
My research career evolved in close alignment with changing societal agendas to address energy scarcity, climate change, and thermal discomfort in buildings and cities. What began as an inquiry rooted in the physics of buildings and passive cooling strategies progressively expanded in scale, first to encompass urban microclimates and urban overheating, and later to the development of innovative materials and large-scale heat mitigation strategies aimed at protecting cities from extreme heat.
Throughout this trajectory, a consistent objective has been to translate scientific understanding into solutions that enhance thermal comfort, reduce energy demand, and promote environmental and social equity. At the same time, this process has not been without constraints: significant barriers frequently emerged in translating research into practice, including limited engagement frameworks with policymakers, institutional inertia, regulatory constraints, and the challenge of communicating complex scientific concepts to non-specialist audiences.
As temperatures rise, researchers are rethinking how cities measure and respond to urban heat. But experts say successful solutions require finding solutions tailored to local conditions rather than relying on one-size-fits-all fixes.
Record-breaking heat and humidity are already upon us at the start of what is predicted to be a scorcher of a summer.
Our cities, with their dark, asphalt surfaces, exhaust-emitting vehicles, and heat-trapping buildings, feel these temperatures the most. Many residents experience at least 8 degrees of additional heat just because of their neighborhood layout, according to Climate Central, which assessed heat patterns in 65 metropolitan areas.
I am deeply honoured to have been named a Member of the Order of Australia by the Governor‑General, a recognition that humbles me and fills me with gratitude. This distinction reflects not only my own efforts but, more importantly, the unwavering support, insight, and dedication of the many collaborators, colleagues, and mentors who have walked alongside me throughout my career.
Why is climate action so slow when the evidence is conclusive?
Prof. Mat Santamouris explained that climate action moves at different speeds because countries have different priorities, and that the overall pace is shaped more by those in power than by the public.
A simple example is political lobbying. Fossil fuel companies spend millions influencing governments and policy processes, which can delay stricter emissions rules or weaken climate targets.
I am deeply honoured and truly grateful to share that Northumbria University, Newcastle UK, has appointed me as a Visiting Professor.
This distinction carries great meaning for me, and I feel a profound sense of
responsibility toward the University’s leadership for their trust and
confidence.
I look forward to contributing with dedication, enthusiasm, and respect for the
academic community that has welcomed me so warmly.
I feel very proud, and I am deeply moved by the awarding of an honorary recognition plaque from the French Grande École nationale des Travaux publics de l'Etat in Lyon. I warmly thank all those who honored me, and I would like to dedicate this award to my unjustly lost friend and ENTPE professor, Gerard Guarraccino. We will always remember you, Gerard
