In the most recent ASHRAE lecture series, Professor Tim Wentz gave the first of a series of three presentations over three weeks to the South African Chapter of ASHRAE. The first was on the topic of A Human Behaviour Approach to Net Zero Energy Buildings hosted by the CCT Committee. The following is a summary of that presentation, with lectures two and three being covered in subsequent issues of Cold Link Africa. This is Part 2 of a five-part series.
The consequences of inaction in the face of climate change are already manifesting worldwide. Freepik.com
Urbanisation is a phenomenon witnessed globally, and its impact is profound. Analysing data from Africa, for instance, reveals a staggering rate of growth in major cities. The astonishing growth per hour in Johannesburg, for instance, stands at an astounding 21 people per hour – and 77 people per hour in Lagos. This trend is not limited to Africa alone but holds true worldwide. From South Africa to the US, from Pakistan to Brazil, cities are witnessing an influx of residents while rural areas experience population decline. Understanding these migration patterns and their implications becomes vital for effective HVAC&R planning.
When we couple urbanisation with projected global population growth, the magnitude of the challenge becomes evident. According to the United Nations, the world population is estimated to approach 10 billion by 2050, with recent reports marking the arrival of the eight billionth person on the planet. To accommodate this population surge, an astonishing 3 500 new buildings must be constructed daily, equivalent to building a new New York City every month for three decades. Such a monumental task underscores the criticality of the HVAC&R industry’s contributions in ensuring energy-efficient and sustainable buildings.
Buildings account for approximately 35% of global energy consumption and contribute around 38% of carbon emissions. As a result, decarbonising the built environment becomes a crucial focus for achieving overall emissions reductions. While it is essential to address other industries like transportation, the HVAC&R sector shoulders the majority of the responsibility. Consequently, the industry’s work is put under the microscope, requiring it to play a central role in combating climate change through sustainable building design and energy efficiency improvements.
The Jevons paradox
Efficiency gains in energy consumption often face the Jevons paradox, where improvements lead to increased energy usage due to lower costs and enhanced usability. The US Energy Information Administration predicts a 28% increase in energy consumption by 2040, reflecting this paradox. The decreasing cost of gas, for example, encourages the purchase of larger vehicles with greater fuel consumption. Recognising and addressing such behavioural tendencies is essential to curbing energy demand and achieving net zero targets.
The consequences of inaction in the face of climate change are already manifesting worldwide. Rising temperatures contribute to extreme weather events, including floods, sea-level rise, wildfires, and heatwaves. Recent examples from South Africa and Pakistan demonstrate the devastating effects of heavy rainfall and flooding. The frequency and intensity of these events continue to escalate, emphasising the urgent need for swift action to mitigate climate change.
Recognising the severity of the climate crisis, the international community united under the Paris Accord in 2015. With a goal of limiting global temperature rise to below 2°C, and ideally 1.5°C, the accord received support from 196 nations, save for one. It is now crucial to translate these commitments into concrete actions. By 2030, the building sector must reduce carbon dioxide emissions by 50% to stay on track.
