There has been an article or two of late arguing that climate systems are beyond human control and that the global climate and what is occurring recently is just part of the natural cycle of things and that our contribution to this is marginal. They argue we cannot, even through concerted action, reduce the increasing global temperature and should concentrate instead on addressing environmental degradation and waste. Of course, these things are not uncoupled and are fine aims in themselves. 

However, as a forensic scientist whose opinions are modified by hard data, I do not buy into this overall argument though it does contain some elements of truth, at least in terms of historical climate changes being real over billions, millions and tens of thousands of years. These changes are accompanied by significant effects on flora and fauna, sometimes gradual, sometimes rapid.

Indeed, occasionally these changes are catastrophic and usually the result of episodes of supervolcano explosions, large cometary or asteroidal impacts, or both, or even massive radiation events from nearby supernovas destroying the earth’s ozone layer. Over geological time they have come close to wiping out all life on Earth and recently in the popular consciousness through movies like Don’t Look Up about the end of the world via a large comet impact, which is itself a metaphor for our past heads-in-the-sand approach to climate change.

Major extinction events and massive climate change accompany these impact events that are themselves immediate. The last major climate change for our planet was arguably the so-called “younger dryas”, which lasted less than 1,500 years and ended the last ice age and brought in the warmer Holocene Epoch about 12,000 years ago. There is accumulating geological evidence that not only was this caused by some kind of planetary impact by an external body like a comet or meteorite but that it also had planetwide rapid and catastrophic, wildfires and major flooding. It acted as a short, sharp shock and reset to the global climate. Human communities were also affected extensively, according to new research, including with remarkable sites like Gobleki Tepe in Türkiye that are also dated to about 12,000 years ago and are currently rewriting our concepts of human civilization.

To 97 percent of climate scientists actually working on the problem for decades, the science for human-induced climate change is compelling if not incontrovertible. For them, the debate is over and has moved on to how humanity can ameliorate the worst impending effects of climate change. This is because they believe many climate tipping points are already past the point of no return and that further negative impacts are built in now regardless. Furthermore, the likelihood of us being able to meet the goals of limiting global warming to less than 1.5 C is likely increasingly unachievable.

To the broader scientific community and scientifically literate population, there is likewise increasing recognition that climate change is not only real but is obvious everywhere from melting ice-caps (Antarctica just the other day carved an ice-shelf the size of New York City), rising sea levels (just ask Pacific Island nations if this is real), extremes of heat and, counter intuitively perhaps, extreme cold but against a backdrop of annual hottest overall records broken year on year around the world and the massive wildfires in Chile, Siberia, California, Spain, Greece, Canada and Australia to name but a few! The melting Siberian and Canadian tundra is also creating weird craters and land changes and the release of millions of metric tons of previously captured methane gas that is about 25 times more potent as a greenhouse gas than CO2.

I was born when the parts per million (ppm) of CO2 was 317 ppm. It’s now 417 ppm. Indeed, atmospheric CO2 did not exceed 300 ppm for the last 800,000 years at least. It’s the clear and incontrovertible result of human actions since the Industrial Revolution of the 19th century and on a linear plot of CO2 levels over nearly 1 million years the rise looks precipitous and vertical. 

China is doing more than any other country to tackle the issues via hydro, wind, solar and other actions like reversing desertification via the largest tree-planting and aggressive environmental degradation reversal programs in human history — to see already the massive strides made here is mind-boggling.

The Hong Kong Special Administrative Region, too can play a better role in this important national endeavor. I have been long struck by the lone wind turbine on Lamma Island in contrast to the three large chimneys of the coal-fired power station currently visible. I know these chimneys will likely disappear as this power station transitions from coal to gas — better, yes, but still burning fossil fuel, so one hopes carbon capture components will either be built in from the start or retrofitted as soon as possible.

On Feb 10, the HKSAR Construction Industry Council held its annual cocktail party where pleas were made to focus on three key areas of innovation, manpower and safety for the future. These are all laudable aims, especially innovation. This should also have a firm intent to include the very latest energy efficiency processes and wherever practicable renewable energy generation components in any new build. Retrofitting of such measures to existing buildings should also be more vigorously pursued. This should be coupled with improved insulation (even in Hong Kong for the cooler months it is important to keep heat in) and in the hotter months to ensure that the cooling effect of air conditioning so many now see as essential is most effective too, aided where possible by novel airflow and passive cooling systems that do not even require power. Rooftop solar and miniwind turbines can certainly help.

 One thing that could be done for our future smart city and for the future Northern Metropolis is to understand where heat is lost and generated in our buildings so that these can be targeted first.

The author is a professor in the Faculty of Science at the University of Hong Kong, the director of its Laboratory for Space Research, and vice-chairman of the Orion Astropreneur Space Academy.

The views do not necessarily reflect those of China Daily.