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September 17th, 2010:

Hot air

Last updated: September 17, 2010

Source: South China Morning Post

Is carbon dioxide really the monster driving climate change? If not, maybe we should prepare for a colder world

In my 20-plus years of studying carbon dioxide and global warming, I have found that hypothetical scares often come before any realities or factual presentations. Horror stories about rising seas inundating land, cities and wildlife, super typhoons and hurricanes, and epic “mega droughts” lasting a decade or longer are all promoted as devastating results of global warming caused by the rising levels of carbon dioxide, according to reports and scientists associated with the UN Intergovernmental Panel on Climate Change (IPCC).

But will any of these scary scenarios about the carbon dioxide monster prove true for Hong Kong?

My recent seminar at the University of Hong Kong’s Department of Earth Sciences offered this simple answer: No. Objective science informs us that the so-called “consensus viewpoints” offered by the IPCC – about man-made carbon dioxide being the dominant factor in climate change – is primarily a political conclusion, and not likely a scientifically accurate one.

The natural and human history of Hong Kong was captured by former British foreign secretary Lord Palmerston around 1841. He described the area as “a barren island with hardly a house upon it!” That was of course explainable by the massive tree-cutting that began during the Song dynasty a millennium ago. It explains why the history of land use changes must surely be a decisive factor in determining the recorded evolution of meteorological and climatic conditions in Hong Kong, before urban greenhouse effects could have played any role.

There is another reason to support a minimal climatic role from atmospheric carbon dioxide. If carbon dioxide is the dominant driver of temperature, why has warming ceased over at least the past decade? Carbon dioxide levels have risen steadily, and yet average planetary temperatures have been stable or even declining since 1995.

Extremist views serve only to increase public panic about climate change – and the media’s, IPCC’s and political establishment’s unwillingness to address the real science only leads to spurious claims that “the science is settled”.

If global temperatures cease to rise, when they are supposedly affected by rapidly rising atmospheric carbon dioxide concentrations, then something more important than carbon dioxide must be driving climate change.

This is also why many peer-reviewed papers on past climatic records (as exemplified by the work of professors Zhonghui Liu and Jason Ali at HKU’s Department of Earth Sciences) tell us convincingly that weather and climate varied naturally in the past and will probably do so in the future, without any ties to atmospheric carbon dioxide levels.

In recent years, the world’s attention has indeed been drawn to the reality and danger of changing climate. Scientists well understand that climatic records comprise alternating periods of warming and cooling all over our earth. Yet, we have rarely considered how modern civilisation would best deal with the challenges of an emerging cooling trend.

There is no excuse for this neglect. Our knowledge about centuries of climate changes clearly indicates that significant cooling can happen on a time frame of a few decades. Several natural drivers of climate have been enumerated that could drive cooling on these time frames and, today, global climate observations seem to be on a razor’s edge between indications of warming and harbingers of cooling.

Thomas Jefferson once remarked: “I have no doubt but that cold is the source of more sufferance to all animal nature than hunger, thirst, sickness and all the other pains of life and death itself put together.” Closer to home, the transition from the Ming to Qing dynasty, a chaotic time owing to crop failures and periods of civil unrest, was likely to be related to a cooling climate. As geographer and historian David Zhang and his HKU colleagues recently noted, “during cold phases, China suffered more often from frequent wars, population decline and dynastic change”.

Another study of the 1,000-year history of typhoon landfalls in Guangdong, by climate scientists from Chinese University of Hong Kong and Louisiana State University, tells us that the two periods of 1660-1680 and 1850-1880 saw the most devastating typhoons.

It is not surprising to find that these two most active typhoon periods also correspond to the coldest and driest periods in northern and central China, as it is often the relatively colder, dryer times that cause the strongest contrasting meteorological conditions in the land, ocean and atmosphere, leading to frequent and damaging typhoons. Therefore, hypothetical scares proposed by global warming scenarios caused by carbon dioxide must raise more serious questions.

What if Hong Kong’s climate turns cold within the next 100 years?

How would the proposed 33 per cent carbon dioxide emissions reduction by 2020 benefit Hong Kong citizens, if it results in soaring energy costs but has no effect on climate?

Why should anyone continue to blindly demonise a life-supporting molecule: carbon dioxide?

Willie Soon is an astrophysicist and geoscientist at the Harvard-Smithsonian Centre for Astrophysics. All views are strictly based on his own scientific research and conclusions